Learn more about Dr. Coy and the creation of his sugar solutions.
Dr Johannes Coy is a world-renowned scientist whose research focuses on the health benefits of sugar awareness. Dr Coy has made a number of important genetic discoveries which change our understanding of cancer and nutrition and make him the leading expert on sugars.
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Book: Fit with Sugar, by Dr Johannes Coy
Dr Coy has written several books about cancer nutrition. His latest book, Fit with Sugar, is now available. In this book, you’ll discover the evolutionary role of sugar in the human body. Consuming too much conventional sugar isn’t good for our health, but with the right sugars, we can stop cell ageing, keep the brain fit, protect against diseases and switch on fat burning. Find out how you can maintain physical and mental performance using natural low- glycaemic sugars and sugar substitutes. The book includes many delicious recipes for cakes, snacks and desserts, so you can implement a sugar-conscious diet easily and intelligently, without giving up sweet treats.
Buy the book: Cancer-Fighting Diet: Diet and Nutrition Strategies to Help Weaken Cancer Cells and Improve Treatment, by Dr Johannes Coy.
Research & Resources
Intracellular Protective Functions and Therapeutical Potential of Trehalose
Trehalose, a naturally occurring saccharide, is a multifunctional molecule that protects cells from various stress factors. It serves as an osmoprotectant, chemical chaperone, free radical scavenger, carbon source, and metabolic regulator, while also contributing to the virulence of bacteria and fungi. Research highlights its potential medical and therapeutic applications, emphasising its role in maintaining cellular homeostasis under stress.
Trehalose inhibits solute carrier 2A (SLC2A) proteins to induce autophagy and prevent hepatic steatosis
The accumulation of lipids in hepatocytes that occurs in nonalcoholic fatty liver disease (NAFLD) can result in liver failure or liver cancer. Trehalose is a ubiquitous sugar that is present in the food consumed by animals. DeBosch et al. determined that trehalose blocked glucose uptake into cells by inhibiting glucose transporters in the plasma membrane, which induced a “starvation”-like response that activated autophagy even in the presence of adequate nutrients and glucose. Furthermore, providing trehalose to mice that are a model of NAFLD prevented lipid accumulation in the liver. As noted by Mardones et al. in the associated Focus, trehalose, which has been previously under investigation to treat neurodegenerative diseases characterized by toxic protein aggregates, may be a “silver bullet” for treating diseases resulting from inadequate cellular degradative metabolism.
Association between HbA1c and carotid atherosclerosis among elderly Koreans with normal fasting glucose
This study investigated the association between glycated hemoglobin (HbA1c) and carotid atherosclerosis in an elderly Korean population with normal fasting glucose. The analysis of 1,133 participants revealed that higher HbA1c levels were independently associated with increased carotid intima-media thickness (IMT), indicating carotid atherosclerosis. This association remained significant after adjusting for various factors. However, fasting insulin and glucose levels did not show a significant association with carotid IMT. These findings suggest that HbA1c may serve as an informative marker for carotid atherosclerosis in elderly individuals with normoglycemia.
Advanced Glycation End Products: Building on the Concept of the “Common Soil” in Metabolic Disease
AGEs play a role in metabolic disorders like obesity and diabetes. They are formed when sugars bind to proteins or fats in our body. AGEs contribute to the development of these disorders by causing insulin resistance and inflammation. They can be produced inside our bodies or come from external sources like pollution, smoking, and unhealthy diets. The accumulation of AGEs in key organs disrupts metabolism and worsens the condition.
Metabolic reprogramming in chondrocytes to promote mitochondrial respiration reduces downstream features of osteoarthritis
This study looked at how changing the way chondrocytes (cartilage cells) get energy could help reduce damage linked to osteoarthritis. Normally, these cells rely heavily on a process called glycolysis, but by replacing glucose with galactose, the researchers forced the cells to depend more on their mitochondria for energy. This change improved mitochondrial function, reduced harmful byproducts like reactive oxygen species and nitric oxide, and decreased levels of MMP13, a molecule that breaks down cartilage. Overall, this suggests that targeting cell metabolism could be a new way to treat osteoarthritis.
Advanced Glycation End Products and Risks for Chronic Diseases: Intervening Through Lifestyle Modification
AGEs are compounds formed when sugars react with proteins, lipids, or nucleic acids in our bodies. They bind to receptors found on different cells and trigger various biological responses. This review summarizes the characteristics of AGEs, how they are measured, their receptors, and how their expression changes in different physiological and disease conditions. The review suggests lifestyle modifications to regulate the AGE-RAGE cycle for improved health.
Advanced Glycation End Products: New Clinical and Molecular Perspectives
AGEs are compounds formed when sugars react with proteins, lipids, or nucleic acids in our bodies. They bind to receptors found on different cells and trigger various biological responses. This review provides an overview of AGEs, including how they are measured and their interactions with receptors. It also discusses how AGE expression changes in different physiological and disease states. Lastly, the review suggests lifestyle choices that can help modulate the AGE-RAGE cycle for better health.
The role of advanced glycation end products in aging and metabolic diseases: bridging association and causality
Accumulation of advanced glycation end products (AGEs) on nucleotides, lipids, and proteins is a natural part of the aging process in all living organisms, including humans. Numerous studies have demonstrated that AGEs and their impaired forms play a role in aging-related changes and the development of age-related diseases. However, there is still much to uncover about how AGEs are formed, their causal relationship with these conditions, and whether interventions can be developed to prevent or reduce AGE-related damage. Invertebrate models such as Drosophila melanogaster and Caenorhabditis elegans can be valuable tools to explore AGE-related pathways and identify potential drugs that can mitigate the harmful effects of AGE accumulation. These models offer insights for further research and intervention development in this area.
Accumulation of advanced glycation end products (AGEs) during aging is associated with age-related changes and diseases. Invertebrate models like Drosophila melanogaster and Caenorhabditis elegans can help study AGE-related pathways and identify potential interventions to mitigate AGE-related damage.
Development and Progression of Non-Alcoholic Fatty Liver Disease: The Role of Advanced Glycation End Products
Non-alcoholic fatty liver disease (NAFLD) affects a significant portion of the adult population and is a leading cause of liver-related illness and mortality worldwide. Treatment mainly relies on lifestyle changes, which can be challenging for most patients. The progression from simple fatty liver to more severe forms, such as non-alcoholic steatohepatitis (NASH) and liver fibrosis, is explained by a “two-hit hypothesis.” Advanced glycation end products (AGEs), formed when sugars react with proteins or lipids, have emerged as major contributors to this second hit, driving the progression from steatosis to NASH through the receptor for AGEs (RAGE). Both endogenous and exogenous AGEs from processed foods can activate RAGE in specific liver cells, promoting NAFLD progression. This review focuses on the pathophysiology of NAFLD, highlighting the role of food-derived AGEs in the development of NASH and liver fibrosis. Additionally, the potential impact of dietary changes to reduce AGEs in food or therapies targeting the AGE/RAGE pathway on disease progression is discussed.
NAFLD affects a large portion of the population and is a major cause of liver-related illness and deaths. The progression from fatty liver to NASH is driven by advanced glycation end products (AGEs) acting through the RAGE receptor. Both endogenous and exogenous AGEs contribute to NAFLD progression. This review focuses on the role of food-derived AGEs in NASH and liver fibrosis and discusses dietary modifications and therapies targeting the AGE/RAGE pathway.
Tagatose as a Potential Nutraceutical: Production, Properties, Biological Roles, and Applications
D-tagatose is a low-calorie nutraceutical that has potential applications in the food and feed industries due to its antidiabetic properties and beneficial effects on gut bacteria. While d-tagatose is present in small amounts in natural foods, it is mainly produced via chemical or biological means. The article provides an overview of the current state of d-tagatose production, properties, and applications.
Downregulation of the Werner syndrome protein induces a metabolic shift that compromises redox homeostasis and limits proliferation of cancer cells
The Werner syndrome protein (WRN) is important for cell growth, and its loss leads to premature aging-related diseases. When WRN is depleted, there is a metabolic shift in cells that weakens pathways involved in detoxification and increases mitochondrial respiration. In cancer cells, this shift counteracts the Warburg effect, altering redox balance and causing DNA damage, which inhibits cell growth and induces senescence. Antioxidant supplementation partially restores cell growth and reduces senescence in WRN-deficient cancer cells. WRN plays a critical role in cancer cell proliferation by influencing metabolism and preventing metabolic stress.
Oral Galactose Provides a Different Approach to Incretin-Based Therapy of Alzheimer’s Disease
Incretin-based drugs, such as GLP-1 and GIP analogues, show promise for treating sporadic Alzheimer’s disease (sAD) due to their neuroprotective and neurotrophic effects. This review highlights oral galactose as a potential sAD therapy, demonstrating its ability to prevent or improve cognitive deficits in a rat model by stimulating GLP-1-mediated effects and normalising cerebral glucose metabolism. Further research is needed to explore galactose’s therapeutic potential, safety, and its interaction with existing GLP-1 therapies.
Trehalose inhibits solute carrier 2A (SLC2A) proteins to induce autophagy and prevent hepatic steatosis
The accumulation of lipids in hepatocytes that occurs in nonalcoholic fatty liver disease (NAFLD) can result in liver failure or liver cancer. Trehalose is a ubiquitous sugar that is present in the food consumed by animals. DeBosch et al. determined that trehalose blocked glucose uptake into cells by inhibiting glucose transporters in the plasma membrane, which induced a “starvation”-like response that activated autophagy even in the presence of adequate nutrients and glucose. Furthermore, providing trehalose to mice that are a model of NAFLD prevented lipid accumulation in the liver. As noted by Mardones et al. in the associated Focus, trehalose, which has been previously under investigation to treat neurodegenerative diseases characterized by toxic protein aggregates, may be a “silver bullet” for treating diseases resulting from inadequate cellular degradative metabolism.
Trehalose alleviates oxidative stress-mediated liver injury and Mallor-Denk body formation via activating autophagy in mice
Trehalose, a disaccharide, has been shown to induce autophagy and reduce cellular stress in various disease models. However, its effects in hepatocytes have not been fully investigated. In a study using mice treated with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC), trehalose was found to induce autophagy, reduce endoplasmic reticulum stress, oxidative stress, Mallory-Denk body formation, and apoptosis in hepatocytes. Electron microscopy revealed the formation of autolysosomes in close proximity to the Mallory-Denk bodies. These findings suggest that trehalose has the potential to be a therapeutic agent for liver diseases associated with oxidative stress by activating autophagy.
Trehalose improves traumatic brain injury-induced cognitive impairment
This study investigated the potential of trehalose, a natural sugar, to treat Alzheimer’s disease (AD) in a mouse model. The study found that trehalose improved the cognitive performance of mice through mechanisms that were independent of the reduction of Aβ protein or activation of autophagy. Trehalose increased the levels of proteins associated with synapses and neurogenesis, suggesting a neuroprotective effect. The study suggests that trehalose may be a potential treatment option for AD and other neurodegenerative disorders.
Trehalose Improves Cognition in the Transgenic Tg2576 Mouse Model of Alzheimer’s Disease
This study investigated the therapeutic effects of trehalose in a mouse model of Alzheimer’s disease (AD). Trehalose treatment improved cognitive performance without significant changes in amyloid-β protein levels or autophagy. There was also no significant alteration in metal levels. However, trehalose treatment led to increased levels of synaptophysin, doublecortin, and progranulin, indicating enhanced synaptic function and neurogenesis. These findings suggest that trehalose may have neuroprotective mechanisms independent of traditional pathways, making it a potential therapeutic option for AD and other neurodegenerative disorders.
Human TKTL1 implies greater neurogenesis in frontal neocortex of modern humans than Neanderthals
This study investigated the role of the TKTL1 gene in neocortex development and its impact on neuroprogenitor numbers. The researchers found that the human-specific amino acid substitution in TKTL1 (hTKTL1) increased the abundance of basal radial glia (bRG), a type of neuroprogenitor associated with increased cortical neuron production. The Neanderthal variant of TKTL1 (aTKTL1) did not have the same effect. Additionally, hTKTL1 promoted the synthesis of specific membrane lipids required for bRG growth. The findings suggest that hTKTL1 contributes to greater neocortical neurogenesis in modern humans, particularly in the frontal lobe, compared to Neanderthals.
Scaling brain neurogenesis across evolution
The neocortex, responsible for cognitive abilities, has expanded and folded in mammals, partly due to basal radial glial cells (bRGs). A study by Pinson et al. reveals that a variant of transketolase-like protein 1 (TKTL1) in modern humans increases the number of bRGs and upper layer projection neurons. This genetic change may contribute to cognitive differences between modern humans and extinct archaic humans.
Trehalose alleviates oxidative stress-mediated liver injury and Mallor-Denk body formation via activating autophagy in mice
This study investigated the effects of trehalose on autophagy, ER stress, oxidative stress-mediated cytotoxicity, and Mallory-Denk body (MDB) formation in hepatocytes. The study used a mice model with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) treatment and administered trehalose through intraperitoneal injection. The results showed that trehalose induced autophagy, reduced ER stress, oxidative stress, MDB formation, and apoptosis in hepatocytes. Electron microscopy revealed autolysosome formation close to the MDBs. These findings suggest that trehalose has the potential to be a therapeutic agent for oxidative stress-related liver diseases by activating autophagy.
Ketogenic diet – a literature review
The ketogenic diet has gained attention for its potential benefits in various health conditions. It has been found to aid in weight reduction, improve lipid profile, and potentially reduce the need for antidiabetic drugs and insulin therapy in type 2 diabetes. Animal studies suggest positive effects in cancer treatment, although human studies are limited. Additionally, there are reports of the ketogenic diet delaying the onset of dementia symptoms. However, the long-term impact on cardiovascular risk is still unknown, emphasizing the need for careful consideration before adopting the diet.
Glucose levels and risk of dementia
This study examined the relationship between glucose levels and the risk of dementia in individuals with and without diabetes. The study included 2,067 participants without dementia, with 232 having diabetes and 1,835 without. The participants were followed for approximately 6.8 years. The findings showed that higher average glucose levels within the preceding 5 years were associated with an increased risk of dementia in both groups. Among participants without diabetes, higher glucose levels were linked to a 1.18 times higher risk of dementia, and among those with diabetes, higher glucose levels were associated with a 1.40 times higher risk of dementia. These results suggest that elevated glucose levels may be a risk factor for dementia, even in individuals without diabetes.
Higher glucose levels associated with lower memory and reduced hippocampal microstructure
This study examined the impact of glycosylated hemoglobin (HbA1c) and glucose levels on memory in healthy older individuals without diabetes or dementia. Lower HbA1c and glucose levels were associated with better memory performance, and the effects were mediated by changes in the hippocampus. The findings suggest that even within the normal range, higher blood glucose levels can negatively affect memory. Lowering glucose levels may improve cognition in older adults
Risk of dementia and cognitive dysfunction in individuals with diabetes or elevated blood glucose
This study investigated the risk of dementia in individuals with type 1 or type 2 diabetes and those with elevated glycosylated hemoglobin (HbA1c) levels. The findings revealed that both type 1 and type 2 diabetes were associated with a higher risk of dementia. Additionally, high HbA1c levels were linked to lower cognitive performance. However, the significance of screening-detected elevated HbA1c in relation to dementia risk requires further clarification.
Insulin resistance predicts brain amyloid deposition in late middle-aged adults
Insulin resistance (IR) has been linked to an increased risk of Alzheimer’s disease (AD), but its association with amyloid deposition in the brain has not been well-studied. This research involved late middle-aged individuals at risk for AD and used positron emission tomography to measure amyloid levels. The findings revealed that higher insulin resistance was associated with greater amyloid deposition in specific brain regions affected by AD, particularly in participants with normoglycemia. This study provides evidence that insulin resistance may contribute to amyloid accumulation in the brain, shedding light on the relationship between metabolic factors and AD pathology.
Gut microbes modulate neurodegeneration
A recent study investigated the role of gut microbes in tau-mediated neurodegeneration, a major factor in Alzheimer’s disease. The study found that gut bacteria play a causative role in inflammation in the central nervous system and peripheral tissues, leading to neurodegeneration. The inflammation was found to be dependent on the specific isoform of apolipoprotein E and was sex-specific. The study highlights the importance of understanding the interplay between gut microbes, APOE, and tau in the development of Alzheimer’s disease
Centella asiatica Protects d-Galactose/AlCl 3 Mediated Alzheimer’s Disease-Like Rats via PP2A/GSK-3β Signaling Pathway in Their Hippocampus
Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by cognitive decline and brain pathology. Centella asiatica (CA), an herb used in traditional medicine, has shown potential in improving cognitive functions. This study investigated the effects of CA on AD-like pathologies induced in rat models. The results revealed that CA increased the levels of protein phosphatase 2 (PP2A), reduced glycogen synthase kinase-3 beta (GSK-3β) levels, and improved the expression of genes associated with cell survival. Additionally, CA prevented structural abnormalities in the hippocampus. This study suggests that CA may have a protective effect against AD-like pathologies by regulating tau proteins, promoting cell survival, and maintaining brain structure.
Metabolism of galactose in the brain and liver of rats and its conversion into glutamate and other amino acids
This animal study measured galactose uptake in various organs. It demonstrated that the liver, brain and muscles can use galactose. They showed that galactose concentrations in the brain remain higher for longer, demonstrating its ability to provided a more sustaining energy. They also found that galactose enhanced the breakdown of toxic ammonia and proposed “galactose as a new means of removal of this neurotoxic compound from the brain in patients suffering from hepatic encephalopathy or Alzheimer’s disease”.
Nicotinamide ribose ameliorates cognitive impairment of aged and Alzheimer’s disease model mice
In this study, the researchers investigated the effects of nicotinamide ribose (NR) supplementation in mice models of Alzheimer’s disease (AD) and aging. The mice were given NR-supplemented food for three months, and their cognitive function, behavior, pathological processes, and biomarkers were assessed. The findings revealed that NR supplementation improved short-term spatial memory in aged mice and contextual fear memory in AD mice. It also inhibited astrocyte activation and reduced the accumulation of amyloid-beta (Aβ) plaques in the brains of AD mice. Additionally, NR supplementation prevented weight gain in both aged and AD mice. These results suggest that NR has selective benefits for AD and aged mice, highlighting its potential as a preventive measure against dementia.
Trehalose improves traumatic brain injury-induced cognitive impairment
In this study, researchers investigated the therapeutic potential of trehalose in a mouse model of traumatic brain injury (TBI). Trehalose, known for its neuroprotective properties, was found to improve behavioral performance in TBI mice without affecting lesion volume or biometals. However, trehalose treatment resulted in an upregulation of synaptic proteins and neurotrophic factors in the contralateral cortex. These findings suggest that trehalose could be an effective treatment option for TBI and other central nervous system disorders
Trehalose Improves Cognition in the Transgenic Tg2576 Mouse Model of Alzheimer’s Disease
This study investigated the therapeutic effects of trehalose in a mouse model of Alzheimer’s disease (AD). Trehalose treatment improved cognitive performance without significant changes in amyloid-β protein levels or autophagy. There was also no significant alteration in metal levels. However, trehalose treatment led to increased levels of synaptophysin, doublecortin, and progranulin, indicating enhanced synaptic function and neurogenesis. These findings suggest that trehalose may have neuroprotective mechanisms independent of traditional pathways, making it a potential therapeutic option for AD and other neurodegenerative disorders.
Human TKTL1 implies greater neurogenesis in frontal neocortex of modern humans than Neanderthals
This scientific article explores the differences in neurogenesis (the formation of new neurons) between modern humans and Neanderthals. Although Neanderthals had brains similar in size to modern humans, researchers discovered a genetic difference in a specific protein called transketolase-like 1 (TKTL1). The modern human variant of this protein, hTKTL1, was found to increase the abundance of basal radial glia (bRG) during neocortex development. These bRG cells play a crucial role in generating neurons. However, the Neanderthal variant of the protein did not have the same effect on bRG. The study suggests that modern humans have a different process of neurogenesis compared to Neanderthals, which may have contributed to unique characteristics of the human brain.
Trehalose alleviates oxidative stress-mediated liver injury and Mallor-Denk body formation via activating autophagy in mice
Trehalose, a disaccharide, has been shown to induce autophagy and reduce cytotoxicity in neurodegenerative diseases. However, its effects on hepatocytes are not fully understood. In a study using a mice model of liver disease, trehalose was found to induce autophagy and decrease ER stress, oxidative stress, Mallory-Denk body (MDB) formation, and apoptosis in hepatocytes. The results suggest that trehalose could be a potential therapeutic agent for oxidative stress-related liver diseases by activating autophagy.
KATP channels are necessary for glucose-dependent increases in amyloid-β and Alzheimer’s disease–related pathology
High blood glucose levels can contribute to Alzheimer’s disease (AD), but the underlying mechanisms are unclear. This study focused on ATP-sensitive potassium (KATP) channels and their role in AD. They found that these channels were present in the human brain and changed with AD progression. Using a mouse model, they discovered that blocking KATP channels reduced the effects of high glucose on Aβ levels, plaque formation, and amyloid precursor protein processing. These findings suggest that targeting KATP channels could be a potential treatment strategy for AD in individuals with diabetes or prediabetes.
Dietary fructose enhances tumour growth indirectly via interorgan lipid transfer
Fructose consumption has risen due to the use of high-fructose corn syrup, and it’s thought that fructose can fuel the growth of some cancers. This study shows that adding fructose to the diet increases tumor growth in animal models of melanoma, breast cancer, and cervical cancer, without causing weight gain or insulin resistance. While cancer cells can’t use fructose directly, liver cells process it into compounds called lysophosphatidylcholines (LPCs), which are then taken up by cancer cells to help build their cell membranes. Adding fructose increased LPC levels in the blood, promoting tumor growth. Blocking a key enzyme involved in processing fructose reduced LPC levels and slowed tumor growth.
Ecological impact of a rare sugar on grapevine phyllosphere microbial communities
Plants host a complex microbiota inside or outside their tissues, and phyllosphere microorganisms can be influenced by environmental, nutritional and agronomic factors. Rare sugars are defined as monosaccharides with limited availability in nature and they are metabolised by only few certain microbial taxa. Among rare sugars, tagatose (TAG) is a low-calories sweetener that stimulates and inhibits beneficial and pathogenic bacteria in the human gut microbiota, respectively. Based on this differential effect on human-associated microorganisms, we investigated the effect of TAG treatments on the grapevine phyllosphere microorganisms to evaluate whether it can engineer the microbiota and modify the ratio between beneficial and pathogenic plant-associated microorganisms. TAG treatments changed the structure of the leaf microbiota and they successfully reduced leaf infections of downy mildew (caused by Plasmopara viticola) and powdery mildew (caused by Erysiphe necator) under field conditions. TAG increased the relative abundance of indigenous beneficial microorganisms, such as some potential biocontrol agents, which could partially contribute to disease control. The taxonomic composition of fungal and bacterial leaf populations differed according to grapevine locations, therefore TAG effects on the microbial structure were influenced by the composition of the originally residing microbiota. TAG is a promising biopesticide that could shift the balance of pathogenic and beneficial plant-associated microorganisms, suggesting selective nutritional/anti-nutritional properties for some specific taxa. More specifically, TAG displayed possible plant prebiotic effects on the phyllosphere microbiota and this mechanism of action could represent a novel strategy that can be further developed for sustainable plant protection.
Cytoprotection by fructose and other ketohexoses during bile salt-induced apoptosis of hepatocytes
Toxic bile salts cause hepatocyte necrosis at high concentrations and apoptosis at lower concentrations. Although fructose prevents bile salt-induced necrosis, the effect of fructose on bile salt-induced apoptosis is unclear. Our aim was to determine if fructose also protects against bile salt-induced apoptosis. Fructose inhibited glycochenodeoxycholate (GCDC)-induced apoptosis in a concentration-dependent manner with a maximum inhibition of 72% +/- 10% at 10 mmol/L. First, we determined if fructose inhibited apoptosis by decreasing adenosine triphosphate (ATP) and intracellular pH (pHi). Although fructose decreased ATP to <25% of basal values, oligomycin (an ATP synthase inhibitor) did not inhibit apoptosis despite decreasing ATP to similar values. Fructose (10 mmol/L) decreased intracellular pH (pHi) by 0.2 U. However, extracellular acidification (pH 6.8), which decreased hepatocyte pHi 0.35 U and is known to inhibit necrosis, actually potentiated apoptosis 1.6-fold. Fructose cytoprotection also could not be explained by induction of bcl-2 transcription or metal chelation. Because we could not attribute fructose cytoprotection to metabolic effects, alterations in the expression of bcl-2, or metal chelation, we next determined if the poorly metabolized ketohexoses, tagatose and sorbose, also inhibited apoptosis; unexpectedly, both ketohexoses inhibited apoptosis. Because bile salt-induced apoptosis and necrosis are inhibited by fructose, these data suggest that similar processes initiate bile salt-induced hepatocyte necrosis and apoptosis. In contrast, acidosis, which inhibits necrosis, potentiates apoptosis. Thus, ketohexose-sensitive pathways appear to initiate both bile salt-induced cell apoptosis and necrosis, whereas dissimilar, pH-sensitive, effector mechanisms execute these two different cell death processes.
Fructose and tagatose protect against oxidative cell injury by iron chelation
To further investigate the mechanism by which fructose affords protection against oxidative cell injury, cultured rat hepatocytes were exposed to cocaine (300 microM) or nitrofurantoin (400 microM). Both drugs elicited massively increased lactate dehydrogenase release. The addition of the ketohexoses D-fructose (metabolized via glycolysis) or D-tagatose (poor glycolytic substrate) significantly attenuated cocaine- and nitrofurantoin-induced cell injury, although both fructose and tagatose caused a rapid depletion of ATP and compromised the cellular energy charge. Furthermore, fructose, tagatose, and sorbose all inhibited in a concentration-dependent manner (0-16 mM) luminolenhanced chemiluminescence (CL) in cell homogenates, indicating that these compounds inhibit the iron-dependent reactive oxygen species (ROS)-mediated peroxidation of luminol. Indeed, both Fe2+ and Fe3+ further increased cocaine-stimulated CL, which was markedly quenched following addition of the ketohexoses. The iron-independent formation of superoxide anion radicals (acetylated cytochrome c reduction) induced by the prooxidant drugs remained unaffected by fructose or tagatose. The iron-chelator deferoxamine similarly protected against prooxidant-induced cell injury. In contrast, the nonchelating aldohexoses D-glucose and D-galactose did not inhibit luminol CL nor did they protect against oxidative cell injury. These data indicate that ketohexoses can effectively protect against prooxidant-induced cell injury, independent of their glycolytic metabolism, by suppressing the iron-catalyzed formation of ROS.
Antioxidant and cytoprotective properties of D-tagatose in cultured murine hepatocytes
D-Tagatose is a zero-energy producing ketohexose that is a powerful cytoprotective agent against chemically induced cell injury. To further explore the underlying mechanisms of cytoprotection, we investigated the effects of D-tagatose on both the generation of superoxide anion radicals and the consequences of oxidative stress driven by prooxidant compounds in intact cells. Primary cultures of hepatocytes derived from male C57BL/6 mice were exposed to the redox cycling drug nitrofurantoin (NFT). Lethal cell injury induced by 300 microM NFT was completely prevented by high concentrations (20 mM) of D-tagatose, whereas equimolar concentrations of glucose, mannitol, or xylose were ineffective. The extent of NFT-induced intracellular superoxide anion radical formation was not altered by D-tagatose, indicating that the ketohexose did not inhibit the reductive bioactivation of NFT. However, the NFT-induced decline of the intracellular GSH content was largely prevented by D-tagatose. The sugar also afforded complete protection against NFT toxicity in hepatocytes that had been chemically depleted of GSH. Furthermore, the ketohexose fully protected from increases in both membrane lipid peroxidation and protein carbonyl formation. In addition, D-tagatose completely prevented oxidative cell injury inflicted by toxic iron overload with ferric nitrilotriacetate (100 microM). In contrast, D-tagatose did not protect against lethal cell injury induced by tert-butyl hydroperoxide, a prooxidant which acts by hydroxyl radical-independent mechanisms and which is partitioned in the lipid bilayer. These results indicate that D-tagatose, which is a weak iron chelator, can antagonize the iron-dependent toxic consequences of intracellular oxidative stress in hepatocytes. The antioxidant properties of D-tagatose may result from sequestering the redox-active iron, thereby protecting more critical targets from the damaging potential of hydroxyl radical.
BSN723T Prevents Atherosclerosis and Weight Gain in ApoE Knockout Mice Fed a Western Diet
This study tests the hypothesis that BSN723T can prevent the development of hyperlipidemia and atherosclerosis in ApoE-/- knockout mice fed a Western (high fat, high cholesterol, and high sucrose) diet. BSN723T is a combination drug therapy consisting of D-tagatose and dihydromyricetin (BSN723). D-tagatose has an antihyperglycemic effect in animal and human studies and shows promise as a treatment for type 2 diabetes and obesity. Many claims regarding BSN723’s pharmacological activities have been made including anti-cancer, anti-diabetic, anti-hypertensive, anti-inflammatory, and anti-atherosclerotic effects. To our knowledge this is the first study that combines D-tagatose and BSN723 for the treatment of hyperlipidemia and the prevention of atherosclerosis.ApoE-deficient mice were randomized into five groups with equivalent mean body weights. The mice were given the following diets for 8 weeks: Group 1 – Standard diet; Group 2 – Western diet; Group 3 – Western diet formulated with D-tagatose; Group 4 – Western diet formulated with BSN723; Group 5 – Western diet formulated with BSN723T. Mice were measured for weight gain, tissue and organ weights, total serum cholesterol and triglycerides and formation of atherosclerosis.The addition of D-tagatose, either alone or in combination with BSN723, prevented the increase in adipose tissue and weight gain brought on by the Western diet. Both D-tagatose and BSN723 alone reduced total cholesterol and the formation of atherosclerosis in the aorta compared to mice on the Western diet. Addition of BSN723 to D-tagatose (BSN723T) did not increase efficacy in prevention of increases in cholesterol or atherosclerosis compared to D-tagatose alone. Addition of either D-tagatose or BSN723 alone to a Western diet prevented weight gain, increases in total serum cholesterol and triglycerides, and the formation of atherosclerosis. However, there was no additive or synergistic effect on the measured parameters with the combination BSN723T treatment.
Feasibility, Safety, and Beneficial Effects of MCT-Based Ketogenic Diet for Breast Cancer Treatment: A Randomized Controlled Trial Study
The present study was aimed to evaluate the safety, tolerability, and beneficial effects of a ketogenic diet (KD) on body composition and blood parameters and survival in patients with breast cancer. In this randomized, controlled trial, 60 patients with locally advanced or metastatic breast cancer and planned chemotherapy, were randomly assigned to a group receiving KDs (n ¼ 30) or to a control group with standard diet (n ¼ 30) for 3 months. Serum biochemical parameters and body composition were analyzed at baseline, every 3 weeks and end of each arm. Compliance and safety of KD were also checked weekly. Fasting blood sugar (FBS) was significantly decreased in intervention group compared to the baseline (84.5 ± 11.3 vs. 100.4 ± 11.8, P ¼ 0.001). A significant inter-group difference was also observed
for FBS level at end of intervention. There was an increasing trend in serum levels of ketone bodies in intervention group (0.007–0.92, P < 0.001). Compared to the control group, BMI, body weight, and fat% were significantly decreased in intervention group in last visit (P < 0.001). No severe adverse side effect was found regarding lipid profile and kidney or
liver marker. Overall survival was higher in KD group compared to the control group in neoadjuvant patients (P ¼ 0.04). Our results suggested that chemotherapy combined with KDs can improve the biochemical parameters, body composition, and overall survival with no substantial side effects in patients with breast cancer.
The Role of the Pentose Phosphate Pathway in Diabetes and Cancer
T2DM is a chronic metabolic disease featured by persistently abnormal hyperglycemia, which can cause serious chronic damage to kidneys, eyes, and nerves. Deregulated insulin secretion and progressive insulin resistance are two main characteristics of T2DM (6). Over the past few decades, studies on the pathogenesis of T2DM have revealed a close relationship between the PPP, obesity-related insulin resistance and T2DM. In this part, we will mainly focus on the role of the PPP in obesity-related insulin resistance, insulin secretion and chronic diabetic complications.
Mystery solved: Trehalose kickstarts autophagy by blocking glucose transport
Although vertebrates cannot synthesize the natural disaccharide trehalose, exogenous administration of trehalose to mammalian cells may be beneficial for protein misfolding disorders. In this issue, DeBosch et al. show that trehalose may also be useful in treating nonalcoholic fatty liver disease and identify inhibition of cellular glucose import through SLC2A (also known as GLUT) transporters as a mechanism by which trehalose stimulates autophagy through the adenosine monophosphate–activated protein kinase (AMPK).
Trehalose inhibits solute carrier 2A (SLC2A) proteins to induce autophagy and prevent hepatic steatosis
The accumulation of lipids in hepatocytes that occurs in nonalcoholic fatty liver disease (NAFLD) can result in liver failure or liver cancer. Trehalose is a ubiquitous sugar that is present in the food consumed by animals. DeBosch et al. determined that trehalose blocked glucose uptake into cells by inhibiting glucose transporters in the plasma membrane, which induced a “starvation”-like response that activated autophagy even in the presence of adequate nutrients and glucose. Furthermore, providing trehalose to mice that are a model of NAFLD prevented lipid accumulation in the liver. As noted by Mardones et al. in the associated Focus, trehalose, which has been previously under investigation to treat neurodegenerative diseases characterized by toxic protein aggregates, may be a “silver bullet” for treating diseases resulting from inadequate cellular degradative metabolism.
Tumor Tissue Acidosis as a Factor Determining the Malignant Phenotype and Tumor Resistance to Chemotherapy
Currently, it has been shown that there are differences in the regulation of the functioning of normal and tumour cells. Based on this, the term “cell reprogramming” was introduced, meaning the formation of
a malignant phenotype.
Trehalose alleviates oxidative stress-mediated liver injury and Mallor-Denk body formation via activating autophagy in mice
Trehalose, a disaccharide, has been shown to induce autophagy and reduce cellular stress in various disease models. However, its effects in hepatocytes have not been fully investigated. In a study using mice treated with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC), trehalose was found to induce autophagy, reduce endoplasmic reticulum stress, oxidative stress, Mallory-Denk body formation, and apoptosis in hepatocytes. Electron microscopy revealed the formation of autolysosomes in close proximity to the Mallory-Denk bodies. These findings suggest that trehalose has the potential to be a therapeutic agent for liver diseases associated with oxidative stress by activating autophagy.
A New Target for Hepatic Fibrosis Prevention and Treatment: The Warburg Effect
Hepatic fibrosis is a major public health problem that endangers human wellbeing. In recent years, a number of studies have revealed the important impact of metabolic reprogramming on the occurrence and development of hepatic fibrosis. Among them, the Warburg effect, as an intracellular glucose metabolism reprogramming, can promote the occurrence and development of hepatic fibrosis by promoting the activation of hepatic stellate cells (HSCs) and inducing the polarization of liver macrophages (KC). Understanding the Warburg effect and its important role in the progression of hepatic fibrosis will assist in developing new strategies for the prevention and treatment of hepatic fibrosis. This review focuses on the Warburg effect and the specific mechanism by which it affects the progression of hepatic fibrosis by regulating HSCs activation and KC polarization. In addition, we also summarize and discuss the related experimental drugs and their mechanisms that inhibit the Warburg effect by targeting key proteins of glycolysis in order to improve hepatic fibrosis in the hope of providing more effective strategies for the clinical treatment of hepatic fibrosis.
Biological function, regulatory mechanism, and clinical application of mannose in cancer.
This study focuses on the potential of mannose, a sugar found in the body, as a treatment for cancer. Unlike glucose, mannose is mainly involved in protein modification rather than energy metabolism. Recent research shows that mannose can directly inhibit cancer cell growth both in lab settings and in animals. Simple supplementation with mannose, either in cell cultures or drinking water, has shown promising results. It also appears to boost the effectiveness of existing cancer treatments like chemotherapy and radiotherapy. Additionally, mannose is being explored as a cancer biomarker and as a component in drug delivery systems to enhance treatment efficacy. The review summarizes the latest findings on mannose’s role in cancer progression, its mechanisms of action, and its applications in cancer diagnosis and therapy.
Increased sugar uptake promotes oncogenesis via EPAC/RAP1 and O-GlcNAc pathways
Recent research highlights that increased aerobic glycolysis, often seen in cancer cells, can actually drive cancer development rather than just being a result of it. In a 3D culture model of human breast cells, overexpressing GLUT3, a glucose transporter, triggered cancer-related signaling pathways, leading to abnormal cell growth and loss of tissue structure. On the other hand, reducing glucose intake in cancer cells helped them form organized structures and halted their growth. Interestingly, the differences between normal and cancerous cells in this model weren’t due to the usual pathways like HIF-1α or mTOR, but were linked to other mechanisms involving RAP1 and specific enzyme interactions. This suggests that targeting the ways in which increased glucose uptake drives cancer could offer new avenues for diagnosis and treatment.
Temporal characterization of serum metabolite signatures in lung cancer patients undergoing treatment
This study explores the potential of using metabolite profiles as biomarkers to predict treatment outcomes in lung cancer patients. Researchers analyzed serum samples from 25 patients undergoing chemotherapy, with or without radiation, using nuclear magnetic resonance (1H-NMR) spectroscopy and gas chromatography-mass spectrometry (GC-MS). The results showed that metabolite profiles varied significantly before, during, and after treatment. Certain metabolites identified via GC-MS, such as hydroxylamine, tridecan-1-ol, and octadecan-1-ol, were linked to patient survival, while others like tagatose and threonine were associated with disease progression. 1H-NMR data were more reflective of the cancer stage and type. The findings suggest that metabolite profiling could serve as a valuable prognostic tool for assessing clinical outcomes in lung cancer patients, although further research with a larger patient group is needed.
Decline of lactate in tumor tissue after ketogenic diet: in vivo microdialysis study in patients with head and neck cancer
This study explores the effects of a ketogenic diet on carbohydrate metabolism in patients with head and neck squamous cell carcinoma (HNSCC), where aerobic glycolysis is crucial for tumor energy supply. Researchers used quantitative microdialysis (μD) to measure metabolic parameters directly in both tumor and tumor-free tissues over several days. The study involved monitoring levels of urea, glucose, lactate, and pyruvate during a 24-hour period on a standard Western diet followed by up to four days on a ketogenic diet.
Results showed that after three days on the ketogenic diet, lactate levels significantly decreased in tumor tissue compared to tumor-free mucosa, while glucose and pyruvate levels increased. This suggests that the ketogenic diet impacts the tumor’s glucose metabolism, possibly indicating that HNSCC tumor cells may use lactate as a fuel source under these conditions. The findings highlight the potential for dietary interventions to influence tumor metabolism in cancer treatment.
AKR1B1 drives hyperglycemia-induced metabolic reprogramming in MASLD-associated hepatocellular carcinoma
This study explored the role of the enzyme AKR1B1 in liver cancer linked to metabolic diseases. The researchers found that AKR1B1 levels were significantly higher in patients with metabolic-associated fatty liver disease (MASLD), metabolic-associated steatohepatitis (MASH), and liver cancer (HCC). In lab tests and mouse models, they discovered that AKR1B1 influences key metabolic processes, promoting the development of liver cancer in a high-sugar diet environment.
The study suggests that inhibiting AKR1B1 could prevent the early stages of liver cancer. The researchers propose AKR1B1 as a potential target for new cancer treatments and suggest measuring AKR1B1 levels in the blood as a diagnostic tool for liver diseases. The study highlights AKR1B1’s role in promoting a specific metabolic process (the Warburg effect) in liver cancer.
Sugary drink consumption and risk of cancer: results from NutriNet-Santé prospective cohort.
This population-based study aimed to examine the association between sugary drinks, artificially sweetened beverages, and the risk of cancer. The study included over 101,000 participants and assessed their beverage consumption using dietary records. The results showed that consuming sugary drinks was significantly associated with an increased risk of overall cancer and breast cancer. However, artificially sweetened beverages did not show a significant association with cancer risk. Additionally, the consumption of 100% fruit juice was also found to be associated with an increased risk of overall cancer. These findings suggest that sugary drinks, including fruit juices, may be modifiable risk factors for cancer and warrant further investigation in future studies.
Blood Glucose and Risk of Incident and Fatal Cancer in the Metabolic Syndrome and Cancer Project (Me-Can): Analysis of Six Prospective Cohorts
This prospective study investigated the association between blood glucose levels and the risk of cancer in six European cohorts. The study included over 274,000 men and 275,000 women, with an average follow-up of 10.4 years. The results showed that higher blood glucose levels were associated with an increased risk of overall incident cancer and fatal cancer, independent of body mass index (BMI) and smoking status. The associations were stronger among women compared to men and for fatal cancer compared to incident cancer. Specific associations were found for various cancer sites, including the liver, gallbladder, respiratory tract, pancreas, urinary bladder, uterine corpus, cervix uteri, and stomach. These findings suggest that abnormal glucose metabolism, beyond BMI, may contribute to an elevated risk of cancer, highlighting the importance of glucose control for cancer prevention.
Serum glucose and risk of cancer: a meta-analysis
In this meta-analysis, the relationship between raised serum glucose levels and the risk of solid cancers was examined. PubMed and Embase databases were searched for relevant studies, and inclusion criteria focused on epidemiological studies with clear definitions of serum glucose levels, cancer type, and well-described statistical methods
The underlying biological mechanisms are not fully understood, but the findings suggest that reducing serum glucose through lifestyle and dietary changes could potentially impact cancer mortality.
Elevated fasting serum glucose levels increase the risk of hepatocellular carcinoma: A prospective cohort study
This study investigated the relationship between fasting blood glucose (FBG) levels and the risk of hepatocellular carcinoma (HCC), a type of liver cancer. The study used competing risk regression models to account for death as an event that may occur before HCC. A cohort of 93,447 participants without prior HCC was followed, and their FBG concentrations were measured. The results showed that higher FBG levels were associated with an increased risk of HCC. Participants with FBG levels between 4.82 mmol/L and 5.49 mmol/L had a 47% increased risk, while those with FBG levels above 5.49 mmol/L had a 69% increased risk. These findings suggest that controlling FBG levels could potentially reduce the risk of HCC in the Chinese population.
Higher glucose and insulin levels are associated with risk of liver cancer and chronic liver disease mortality among men without a history of diabetes
This prospective study examined the associations between fasting glucose, insulin, and insulin resistance with liver cancer and chronic liver disease (CLD) mortality in Finnish male smokers. Participants were followed for up to 22 years, and various risk factors were considered. The results showed that elevated fasting glucose levels were positively associated with liver cancer risk. Undiagnosed, biochemically defined diabetes also increased the risk of liver cancer and CLD mortality. Similarly, higher serum insulin levels and insulin resistance were independently associated with increased risks of liver cancer and CLD mortality. These findings suggest that insulin and glucose dysregulation, even in the absence of diagnosed diabetes, may play a significant role in the development of liver cancer and CLD.
Insulin Resistance Is Associated with Early Gastric Cancer: A Prospective Multicenter Case Control Study
This study aimed to investigate the factors associated with early gastric cancer and evaluate the predictive value of the homeostasis model assessment of insulin resistance (HOMA-IR) index, fasting glucose, and lipid profile. The study included 63 patients with early gastric cancer and a matched control group. The results showed that higher levels of total cholesterol, fasting glucose, body mass index, and diastolic blood pressure were associated with an increased risk of early gastric cancer. Furthermore, hyperglycemia, lower high-density lipoprotein cholesterol levels, and a low HOMA-IR level were identified as potential risk factors for early gastric cancer.
Prostate Size Correlates with Fasting Blood Glucose in Non-Diabetic Benign Prostatic Hyperplasia Patients with Normal Testosterone Levels
This retrospective study aimed to evaluate the correlations between BMI, fasting glucose, insulin, testosterone level, insulin resistance, and prostate size in non-diabetic benign prostatic hyperplasia (BPH) patients with normal testosterone levels. The study included 212 patients who underwent transurethral resection of the prostate (TURP) due to medical treatment failure. The results showed that prostate size correlated positively with age, PSA levels, and fasting glucose levels, but not with BMI, testosterone, insulin level, or insulin resistance. Testosterone levels were inversely correlated with BMI, insulin level, and insulin resistance, but not with age, prostate size, PSA, or fasting glucose level. Multiple adjusted regression analysis revealed that prostate size was associated with elevated PSA and increased fasting glucose levels. In non-diabetic BPH patients with normal testosterone levels, fasting glucose level was identified as an independent risk factor for prostate hyperplasia.
Effects of a novel palatinose based enteral formula (MHN-01) carbohydrate-adjusted fluid diet in improving the metabolism of carbohydrates and lipids in patients with esophageal cancer complicated by diabetes mellitus
A study investigated the effects of a novel enteral formula (MHN-01) on perioperative management of patients with esophageal cancer and diabetes mellitus. MHN-01 showed promising results in suppressing post-prandial hyperglycemia, improving lipid metabolism, and reducing fat accumulation in animal experiments. In clinical cases, MHN-01 was successfully used in the perioperative management of patients with severe diabetes mellitus and esophageal cancer.
Autophagy induction by trehalose: Molecular mechanisms and therapeutic impacts
The role of trehalose as an innovative drug in the treatment of neurodegenerative diseases and other illnesses opening a new scenario of intervention in conditions difficult to be treated.
Trehalose protects against oxidative stress by regulating the Keap1-Nrf2 and autophagy pathways
This study looked at the potential of trehalose, a natural sugar found in plants and microorganisms, to activate a pathway that regulates cellular balance and reduces oxidative stress. The study found that trehalose can activate this pathway in a way that induces autophagy (cellular cleaning) and increases the expression of antioxidant factors. This suggests that trehalose has the potential to be a useful treatment for chronic diseases that involve oxidative stress and problems with cellular balance.
Galactose inhibits migration and invasive growth of cancer cells
This study provides clear evidence that specific types of dietary sugar are implicated in either feeding, or starving, the spread of cancer: “In order to test whether TKT’s promotion of colorectal cancer metastasis is dependent on glycolysis, we used galactose which induced cells to survive on ATP provided by mitochondrial respiration instead of glucose.”
How Sugar Suppresses the Immune System Hypoxia-Related Gene-Based Signature Can Evaluate the Tumor Immune Microenvironment
Researchers investigated the correlation between hypoxia-related genes and the prognosis of colon adenocarcinoma (COAD) patients. They identified four hypoxia genes (TKTL1, SLC2A3, ALDOB, and ENO3) and developed a hypoxia risk model to predict overall survival. The model showed stability and could be used to assess the prognosis of COAD patients. Additionally, the hypoxia risk score was found to be associated with immunosuppression in the tumor microenvironment.
How Sugar Suppresses the Immune System A hypoxia-linked gene signature for prognosis prediction
The study aimed to develop a prognostic model using hypoxia-linked genes to predict the prognosis of hepatocellular carcinoma (HCC) patients and investigate the relationship between hypoxia and immune status in the tumor microenvironment (TME). Six hypoxia-linked genes (HMOX1, TKTL1, TPI1, ENO2, LDHA, and SLC2A1) were used to create the prediction model. The model showed satisfactory estimation power and could independently predict overall survival (OS) in HCC patients. Additionally, the model could distinguish between high- and low-risk groups based on immune status. The findings have implications for improving the diagnosis and treatment of HCC.
A hypoxia-linked gene signature for prognosis prediction and evaluating the immune microenvironment in patients with hepatocellular carcinoma
This study aimed to develop a prognostic model using six hypoxia-linked genes to predict the prognosis of hepatocellular carcinoma (HCC) patients and investigate the relationship between hypoxia and immune status in the tumor microenvironment. The model was created using transcriptome and clinical data from TCGA and validated using data from GEO. The model showed satisfactory estimation power and could independently predict overall survival in HCC patients. It also successfully distinguished between high- and low-risk groups in terms of immune status. The findings have implications for improving the diagnosis and treatment of HCC.
TKTL1 Knockdown Impairs Hypoxia-Induced Glucose-6-phosphate Dehydrogenase and Glyceraldehyde-3-phosphate Dehydrogenase Overexpression
This study investigated the role of transketolase-like-1 (TKTL1) in metabolic reprogramming under hypoxic conditions in leukemia cells. Using THP-1 AML cells, the researchers found that knockdown of TKTL1 led to decreased activities of transketolase (TKT), glucose-6-phosphate dehydrogenase (G6PD), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). This resulted in impaired hypoxia-induced overexpression of G6PD and GAPDH, affecting the redox capacity of NADPH- and NADH-related cells. TKTL1 knockdown also hindered the transcription of genes involved in glucose, pentose phosphate pathway (PPP), and amino acid metabolism, preventing cells from switching to enhanced glycolysis under hypoxia. These findings highlight the crucial role of TKTL1 in the metabolic adaptation to hypoxia in THP-1 AML cells, impacting glucose and amino acid metabolism through modulation of key enzymes and transporters.
Growth of human gastric cancer cells in nude mice is delayed by a ketogenic diet supplemented with omega-3 fatty acids and medium-chain triglycerides
In this study, researchers investigated the effects of a ketogenic diet enriched with omega-3 fatty acids and medium-chain triglycerides (MCT) on tumour growth in a mouse model of gastric adenocarcinoma. The ketogenic diet, characterized by low carbohydrate intake and high fat content, significantly delayed tumour growth compared to a standard diet. Tumours in the ketogenic diet group exhibited larger necrotic areas and fewer blood vessels in the viable tumour cell regions. These tumour cells in the border zone showed a glycolytic phenotype. The results suggest that the ketogenic diet can effectively impede tumour growth in this mouse model, although further research is needed to explore its impact on other tumour-related processes such as invasive growth and metastasis.
Transketolase Serves as a Biomarker for Poor Prognosis in Human Lung Adenocarcinoma
Half of the patients who undergo surgical resection for early-stage lung cancer experience relapse and succumb to the disease, despite the use of adjuvant chemotherapy, which only minimally reduces the risk of relapse. Identifying the factors driving relapse, determining who would benefit from adjuvant therapy, and finding new targets are crucial. The pentose phosphate pathway (PPP) has been implicated in cancer, but the role of transketolase (TKT), an enzyme involved in the PPP, in lung adenocarcinoma (LUAD) is not well understood. This study examined TKT expression in LUAD and found that it was elevated in cancer tissues compared to normal tissues. High TKT expression was associated with advanced tumor stage. Additionally, inhibiting TKT led to tumor cell apoptosis and cell cycle arrest. These findings highlight the significant role of TKT in LUAD progression and prognosis, suggesting its potential as a biomarker for predicting recurrence after lung cancer resection.
Inhibition of Transketolase Improves the Prognosis of Colorectal Cancer
This study explored the role of transketolase (TKT) in colorectal cancer (CRC). TKT was found to be up-regulated in CRC and associated with poor prognosis. Inhibiting TKT reduced tumor cell viability, proliferation, migration, and induced apoptosis. TKT may serve as a prognostic biomarker and therapeutic target for CRC.
Hypoxia-Related Gene-Based Signature Can Evaluate the Tumor Immune Microenvironment and Predict the Prognosis of Colon Adenocarcinoma Patients
This study focused on the prognosis of colon adenocarcinoma (COAD) patients in relation to hypoxia-related genes. A prognostic model using four hypoxia genes (TKTL1, SLC2A3, ALDOB, and ENO3) was constructed to predict overall survival. The hypoxia risk score from the model was also found to be associated with immunosuppression in the tumor microenvironment. This model provides a stable prediction of overall survival for COAD patients.
TKTL1 participated in malignant progression of cervical cancer cells via regulating AKT signal mediated PFKFB3 and thus regulating glycolysis
This study investigated the role of TKTL1 in cervical cancer (CC) cells and its involvement in glucose metabolism. The findings revealed that TKTL1 expression was increased in CC cells and its inhibition led to decreased cell proliferation, invasion, migration, and glycolysis. TKTL1 was shown to activate PFKFB3 through AKT signaling, contributing to the malignant progression of CC cells. Animal experiments also demonstrated that TKTL1 inhibition reduced tumor volume and improved histopathological status. Overall, TKTL1 plays a crucial role in CC by regulating glucose metabolism through AKT-mediated pathways.
Transketolase promotes colorectal cancer metastasis through regulating AKT phosphorylation
This study focused on the role of transketolase (TKT) in colorectal cancer (CRC). The findings revealed that TKT expression was significantly increased in CRC and correlated with poor prognosis. TKT was found to promote CRC cell growth and metastasis. Further investigation showed that TKT interacted with GRP78 and enhanced glycolysis in CRC cells by increasing AKT phosphorylation, thereby facilitating metastasis. These findings suggest that TKT could serve as a prognostic indicator for CRC and provide insights for developing new treatment targets for the disease.
Hyperglycemia induces metabolic reprogramming into a glycolytic phenotype and promotes epithelial-mesenchymal transitions via YAP/TAZ-Hedgehog signaling axis in pancreatic cancer
This study investigated the impact of hyperglycemia on pancreatic ductal adenocarcinoma (PDAC). The findings revealed that hyperglycemia promotes epithelial-mesenchymal transition (EMT) and metabolic reprogramming in PDAC cells, leading to a glycolytic phenotype. Hyperglycemia also enhances chemoresistance and activates the Hedgehog pathway, contributing to tumor progression. Additionally, hyperglycemia stimulates YAP/TAZ expression in cancer-associated fibroblasts, leading to the production of tumor-promoting proteins in the tumor microenvironment. Inhibition of YAP/TAZ reverses these effects, suggesting YAP/TAZ as a potential therapeutic target in PDAC.
Ketogenic diets slow melanoma growth in vivo regardless of tumor genetics and metabolic plasticity | Cancer & Metabolism | Full Text (biomedcentral.com)
This study investigated the impact of ketogenic diets on melanoma progression and metabolism. The findings demonstrated that ketogenic diets effectively reduced tumor growth in mice with genetically and metabolically diverse melanoma xenografts. The diets also reduced metastasis in mice with a functional immune system. Targeted metabolomics analysis revealed that ketogenic diets induced changes in amino acid metabolism and reduced levels of alpha-amino adipic acid, a cancer biomarker, in circulation and tumors. Additionally, ketogenic diets affected sphingomyelin levels and hydroxylation in plasma and tumors. These findings suggest that ketogenic diets have antitumor effects on melanoma, regardless of genetic background or immune status, by altering multiple metabolic pathways and creating an unfavorable environment for tumor cell proliferation.
Scaling brain neurogenesis across evolution
The neocortex, responsible for cognitive abilities, has expanded and folded in mammals, partly due to basal radial glial cells (bRGs). A study by Pinson et al. reveals that a variant of transketolase-like protein 1 (TKTL1) in modern humans increases the number of bRGs and upper layer projection neurons. This genetic change may contribute to cognitive differences between modern humans and extinct archaic humans.
P1249: Inhibition of The Pentose-Phosphate-Pathway (Ppp) Mediates Macrophage Reprogramming From Supportive Bystander Function Towards Antibody-Dependent Lymphoma Cell Clearance And Lymphoma Suppression
This study investigated the metabolic pathways regulating macrophages in the tumor microenvironment (TME) of lymphoma and their impact on macrophage function in therapy. Inhibition of the pentose phosphate pathway (PPP) increased macrophage phagocytosis of lymphoma cells and induced morphological and functional changes. PPP inhibition also altered immune profiles and reduced support for CLL cells. Multiomics analyses revealed connections between PPP inhibition, metabolism, and immunity. In a mouse model, PPP inhibition improved macrophage maturation, prolonged survival, and enhanced pro-inflammatory polarization. The PPP was identified as a targetable modulator of macrophage function in lymphoma therapy.
Fructose and the Liver
In this study, it is revealed that fructose overconsumption is linked to metabolic syndrome and liver-related diseases. The detrimental effects include insulin resistance, inflammation, non-alcoholic fatty liver disease (NAFLD), and an increased risk of liver cancer. The study demonstrates that fructose activates proinflammatory, fibrogenic, and oncogenic pathways, particularly in the liver.
A dose- and time-dependent effect of oxythiamine on cell growth inhibition in non-small cell lung cancer
In this study, the researchers investigated the effect of Oxythiamine (OT), an antimetabolite of Thiamine-dependent enzymes (TDEs), on the growth of non-small-cell lung cancer (NSCLC) cells. They co-cultured A549 cells with varying doses of OT and examined cell proliferation and apoptosis. The results showed that OT treatment significantly inhibited the proliferation of A549 cells in a dose- and time-dependent manner. The inhibition of TDEs led to cell cycle arrest and induced apoptotic cell death. These findings suggest that OT could be a potential therapeutic target for NSCLC treatment.
The role of transketolase in human cancer progression and therapy
In this review, the researchers highlight the significance of Transketolase (TKT) and its family members, TKTL1 and TKTL2, in cancer regulation. TKT and TKTL1 have been implicated in various cancer-related processes, including cell proliferation, metastasis, invasion, chemoradiotherapy resistance, and patient prognosis. The detection of TKTL1 levels using EDIM technology has shown promise as a sensitive and specific method for early malignancy detection and evaluating the effectiveness of surgery. While targeted TKT therapy has demonstrated positive effects in suppressing cancer, it is important to consider potential detrimental effects on the organism. The review discusses the role of TKT in different tumors, underlying mechanisms, and its clinical applications, providing insights for future targeted therapy and cancer-related research.
Ingredients such as trehalose and hesperidin taken as supplements or foods reverse alterations in human T cells, reducing asbestos exposure-induced antitumor immunity
This study investigated the potential of trehalose (Treh) and glycosylated hesperidin (gHesp) to reverse the reduced antitumor immunity caused by asbestos exposure. Human immune cells exposed to asbestos were treated with Treh or gHesp, and gene expression levels related to immune response were assessed. The results suggest that Treh and gHesp may have the ability to restore antitumor immunity in T helper cells affected by asbestos exposure. Further research is needed to confirm these findings and evaluate their efficacy in asbestos-exposed populations.
Expression of Transketolase TKTL1 in Iraqi Breast Cancer Females
This scientific article discusses the expression of the TKTL1 gene in breast cancer patients and its relationship with clinical characteristics. The study involved 50 Iraqi breast cancer patients and 25 healthy controls. The findings revealed that breast cancer patients showed increased expression of the TKTL1 gene compared to the control group. The level of gene expression was higher on the right side compared to the left side. Significant differences in gene expression were observed based on tumor site, tumor grade, and cancer stage. The results suggest that TKTL1 gene expression may serve as a potential biomarker for early detection of breast cancer.
Trehalose alleviates oxidative stress-mediated liver injury and Mallor-Denk body formation via activating autophagy in mice
This study investigated the effects of trehalose on autophagy, ER stress, oxidative stress-mediated cytotoxicity, and Mallory-Denk body (MDB) formation in hepatocytes. The study used a mice model with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) treatment and administered trehalose through intraperitoneal injection. The results showed that trehalose induced autophagy, reduced ER stress, oxidative stress, MDB formation, and apoptosis in hepatocytes. Electron microscopy revealed autolysosome formation close to the MDBs. These findings suggest that trehalose has the potential to be a therapeutic agent for oxidative stress-related liver diseases by activating autophagy.
Hyperglycemia and cancer in human lung carcinoma by means of Raman spectroscopy and imaging
This study used Raman spectroscopy and imaging to analyze human lung cancer cells and their response to glucose and deuterated glucose under normal and hyperglycemic conditions. The results showed that substituting glucose with deuterated glucose allowed the distinction between de novo lipid synthesis and lipid uptake from the diet. It was observed that glucose is primarily used for de novo lipid synthesis and that high glucose levels decrease mitochondrial oxidative phosphorylation, leading to a shift towards glycolysis (Warburg effect). This suggests that hyperglycemia may contribute to a more aggressive cancer phenotype by inhibiting oxidative phosphorylation and apoptosis.
Molecular Mechanisms for Ketone Body Metabolism, Signaling Functions, and Therapeutic Potential in Cancer
Ketone bodies (KBs) are alternative energy sources to glucose during nutrient deprivation. They play a role in cellular signaling, protect against inflammation and oxidative stress, and have therapeutic potential in various diseases, including cancer. Abnormal KB metabolism is involved in tumorigenesis, and targeting it through dietary interventions, like ketogenic diets, shows promise in cancer therapy. This review explores the molecular mechanisms of KB metabolism and their potential use in cancer treatment.
High Blood Sugar Levels Trigger Transition of Benign to Malignant Tumours in Pancreatic Cancer
High blood sugar levels (hyperglycemia) in pancreatic ductal adenocarcinoma (PDAC) cause metabolic changes that promote the transition of cancer cells and increase their resistance to chemotherapy. This is mediated by the overexpression of certain proteins (YAP and TAZ) and activation of the Hedgehog pathway. Hyperglycemia also affects the surrounding tissue, stimulating the production of proteins that support tumor growth. Blocking the activity of YAP and TAZ can reverse these effects and improve treatment outcomes.
Preneoplastic cells switch to Warburg metabolism from their inception exposing multiple vulnerabilities for targeted elimination
Early stages of cancer involve a metabolic shift known as the “Warburg effect,” where cells rely on glycolysis instead of oxidative phosphorylation. In a zebrafish model, preneoplastic cells quickly activate glycolysis and impair oxidative phosphorylation. Blocking glycolysis inhibits cell growth, while enhancing glucose availability promotes proliferation and reduces cell death. Targeting impaired oxidative phosphorylation with metformin induces cell death specifically in preneoplastic cells. Additionally, mitochondrial fragmentation occurs early on and blocking it leads to increased cell death. These findings offer insights for targeted tumor prevention strategies.
High glucose promotes benign prostatic hyperplasia by downregulating PDK4 expression
This study investigated how high levels of glucose can affect prostate cells and potentially lead to benign prostatic hyperplasia (BPH), a condition that affects many aging men. The researchers focused on a specific gene called Pyruvate dehydrogenase kinase 4 (PDK4), which is involved in glucose metabolism and the development of various diseases. They treated normal and BPH prostate cells with high glucose levels and found that it caused these cells to grow more, change their characteristics, reduce cell death, and decrease PDK4 expression. Patients with diabetes-related BPH also had lower levels of PDK4. When they manipulated PDK4 levels in these cells, it had corresponding effects. They also used a medication called Rosiglitazone, which can increase PDK4 expression and suggested it might be a potential treatment for BPH. This study implies that high glucose levels could contribute to BPH development by reducing PDK4, making it a possible target for therapy.
Feasibility, Safety, and Beneficial Effects of MCT-Based Ketogenic Diet for Breast Cancer Treatment: A Randomized Controlled Trial Study, Nutrition and Cancer
This study aimed to explore the safety and benefits of a ketogenic diet (KD) on patients with breast cancer undergoing chemotherapy. In a 3-month randomized trial with 60 participants, half followed a KD, and the other half maintained a standard diet. The KD group showed reduced fasting blood sugar, increased ketone levels, and significant improvements in BMI, body weight, and fat percentage compared to the control group. No severe adverse effects were observed in lipid profile or kidney/liver markers. Notably, overall survival was higher in the KD group, suggesting that combining chemotherapy with KD may enhance biochemical parameters and body composition while improving survival in breast cancer patients without major side effects.
Warburg effect-related risk scoring model to assess clinical significance and immunity characteristics of glioblastoma
This study examined glioblastoma (GBM), an aggressive brain tumor. Researchers investigated the Warburg effect, an abnormal energy metabolism in tumors, and its impact on GBM prognosis and the immune environment.
They developed a predictive model using GBM data, identifying age, treatment, and Warburg effect gene scores as key factors for prognosis. A predictive tool showed high accuracy.
The study revealed that high Warburg effect gene scores were associated with an immunosuppressive environment, limiting the effectiveness of immunotherapy. Drugs targeting these genes inhibited GBM cell growth in lab tests.
In summary, the Warburg effect affects GBM prognosis and the immune environment, and targeting related genes may offer new treatment options.
Ketogenic diet – a literature review
The ketogenic diet has gained attention for its potential benefits in various health conditions. It has been found to aid in weight reduction, improve lipid profile, and potentially reduce the need for antidiabetic drugs and insulin therapy in type 2 diabetes. Animal studies suggest positive effects in cancer treatment, although human studies are limited. Additionally, there are reports of the ketogenic diet delaying the onset of dementia symptoms. However, the long-term impact on cardiovascular risk is still unknown, emphasizing the need for careful consideration before adopting the diet.
Significant Systemic Insulin Resistance is Associated With Unique Glioblastoma Multiforme Phenotype
This study investigated the relationship between insulin resistance and a specific type of brain cancer called glioblastoma multiforme (GBM), which is characterized by the presence of gemistocytes (GCs). These GCs are typically associated with reactive astrocytes, a type of brain cell. The study aimed to find a connection between insulin resistance and the presence of GCs in newly diagnosed GBM patients.
The researchers looked at medical records of 220 patients with newly diagnosed GBM. Among these patients, 26.3% had a history of type 2 diabetes at the time of diagnosis. They found that in the group of GBM patients with GCs, poorly-controlled diabetes was more common compared to the group without GCs. Specifically, there was a higher prevalence of poorly-controlled diabetes in the GC-GBM group (18.75%) compared to the non-GC GBM group (9.5%). In the subset of diabetic patients, those with GC-GBM were more likely to exhibit characteristics of insulin resistance, such as being male, morbidly obese, and not using synthetic insulin before diagnosis.
In conclusion, this study suggests that systemic metabolic factors related to insulin resistance, including type 2 diabetes, morbid obesity, and male gender, are associated with a distinct histological subtype of GBM characterized by the presence of GCs. This association is particularly significant in poorly-controlled type 2 diabetes GBM patients who do not use synthetic insulin. The findings highlight the potential relevance of glucose metabolism in astrocytes and its connection to high-grade brain tumors. Further research is needed to explore how patients’ metabolic status, tumor characteristics, molecular changes, and use of anti-diabetic drugs impact survival in GBM patients.
Hyperinsulinemia acts via acinar insulin receptors to initiate pancreatic cancer by increasing digestive enzyme production and inflammation
This study explores the link between pancreatic cancer, obesity, type 2 diabetes, and high levels of insulin in the blood (hyperinsulinemia). It is known that high insulin production is an independent risk factor for cancer, including pancreatic cancer. Previous research showed that reducing insulin production could suppress the development of pre-cancerous pancreatic lesions (PanIN) in mice with a specific genetic mutation (Kras). However, the precise mechanisms behind this connection and whether hyperinsulinemia directly affects PanIN precursor cells were unclear.
The study found that insulin receptors (Insr) in pancreatic acinar cells expressing the KrasG12D mutation were not essential for regulating glucose levels but were crucial for the formation of PanIN lesions in the presence of diet-induced hyperinsulinemia and obesity. The mechanism behind this involved an increase in the translation of digestive enzyme proteins, which led to local inflammation and the development of PanIN lesions in vivo. In laboratory experiments, insulin was shown to promote the transformation of acinar cells into ductal cells (acinar-to-ductal metaplasia) in a manner dependent on trypsin and insulin receptors.
In summary, this study sheds light on how obesity-driven hyperinsulinemia is connected to the development of pancreatic cancer. It shows that insulin receptors in pancreatic cells are not required for regulating blood sugar but play a crucial role in the formation of pre-cancerous pancreatic lesions under conditions of obesity and high insulin levels. The study provides insights into the mechanisms underlying the link between hyperinsulinemia and the development of pancreatic cancer.
Scaling brain neurogenesis across evolution
The neocortex, responsible for cognitive abilities, has evolved and expanded across mammals. Humans’ advanced cognitive abilities are attributed to neocortex size and structure. Basal radial glial cells (bRGs) play a role in neocortex expansion and folding. A study by Pinson et al. found that a variant of transketolase-like protein 1 (TKTL1) in modern humans increases the number of bRGs and upper layer projection neurons. This genetic change may contribute to cognitive differences between modern humans and extinct archaic humans.
Targeting Glucose Metabolism for HPV-Associated Cervical Cancer: A Sweet Poison
Targeting glucose metabolism (glycolysis and PPP) provides a new strategy for future clinical treatment of cervical cancer and offers a theoretical basis for the treatment of HPV-related diseases.
Targeting Metabolic Vulnerabilities in Pancreatic Cancer: The Synergistic Anti-Tumour Effects of a Ketogenic Diet and IDH1 Inhibition
A ketogenic diet exerts a strong anti-tumour effect in multiple pancreatic cancer mouse models, likely due to low glucose and increased fatty acid load. The metabolic shift towards an oxidative phosporylation (OXPHOS) phenotype makes pancreatic cancer cells particularly vulnerable to antioxidant and mitochondrial inhibitiors.
Proteomic Characterization of Gastric Cancer Response to Chemotherapy and Targeted Therapy Reveals New Therapeutic Strategies
Chemotherapy and targeted therapy are primary treatments for gastric cancer (GC), but drug resistance reduces their effectiveness. This study analyzed the proteome of 206 tumor tissues from GC patients undergoing chemotherapy or anti-HER2 therapy, identifying four subtypes (G-I–G-IV) with distinct clinical and molecular features.
Patients with high MSI-signature GC responded well to docetaxel combination therapy, showing an anticancer immune response. Those with high T cell receptor signaling responded better to anti-HER2 therapy, while activation of the extracellular matrix/PI3K-AKT pathway reduced the effectiveness of trastuzumab. The study found that CTSE enhances chemosensitivity to docetaxel, while TKTL1 reduces it.
Prognostic models were developed to predict therapeutic responses with high accuracy and validated in an independent cohort. This research offers valuable insights into the mechanisms and indicators of chemotherapy and targeted therapy in GC.
Human Papillomavirus Type 16 E6 Promotes Cervical Cancer Proliferation by Upregulating Transketolase Enzymatic Activity Through the Activation of Protein Kinase B
Over 99% of precancerous cervical lesions are linked to HPV, with types 16 and 18 present in over 70% of cervical cancer cases. The E6 gene of HPV16, which degrades p53, contributes to cancer but doesn’t fully explain HPV16’s oncogenic effects. This study explored additional targets of HPV16 E6.
We found significant changes in nonoxidative pentose phosphate pathway (PPP) metabolites in HPV16-positive cells. In HPV-negative cervical cancer cells (C33A), HPV16 E6 increased cell proliferation by activating the nonoxidative PPP and upregulating the enzyme transketolase (TKT) via AKT activation. TKT is highly expressed in cervical cancer and linked to poor prognosis.
Using the TKT inhibitor oxythiamine (OT) reduced tumor growth, with even better results when combined with cisplatin (DDP). Thus, HPV16 E6 promotes cervical cancer growth by enhancing TKT activity through AKT activation, and OT, especially with DDP, shows promise in inhibiting HPV16-positive cervical cancer.
Acidosis-medicated Increase in IFN-y-induced PD-L1 Expression on Cancer Cells as an Immune Escape Mechanism in Solid Tumors
Immune checkpoint inhibitors are effective cancer treatments but often limited by the tumor microenvironment (TME). This study shows that tumor acidity increases PD-L1 expression on cancer cells, helping them evade the immune system. Acidosis boosts IFN-γ activity, leading to higher PD-L1 levels.
Researchers found that neutralizing acidity with sodium bicarbonate reduced PD-L1 expression and tumor growth in responsive tumors. This effect was absent in nonresponsive tumors and IFN-γ-deficient mice.
These findings suggest tumor acidity and IFN-γ-induced PD-L1 are key to immune escape, offering potential biomarkers and new strategies to improve immunotherapy.
Metbolic Regulation of Homologous Recombinaton Repair by MRE11 Lactylation
Lactylation, where lactate attaches to proteins, affects their function. This study found that MRE11, a key DNA repair protein, is lactylated at K673 when DNA is damaged, aiding its ability to repair DNA through homologous recombination (HR). Blocking the enzymes CBP or LDH reduced this lactylation, impairing HR and making cancer cells more sensitive to chemotherapy. A peptide blocking MRE11 lactylation also increased cancer cells’ sensitivity to treatments like cisplatin. These findings suggest that targeting MRE11 lactylation could enhance cancer therapy effectiveness
Metabolic Management of Microenvironment Acidity in Glioblastoma
Glioblastoma (GBM) relies on fermentation metabolism for biomass and energy production, despite the tumor’s cellular and genetic diversity. This shift from respiration to fermentation is due to defects in mitochondrial structure and function in GBM tissue. Glucose and glutamine are the primary fuels for GBM growth. The waste products of GBM fermentation (lactic acid, glutamic acid, and succinic acid) acidify the tumor microenvironment, contributing to drug resistance, increased invasion, immunosuppression, and metastasis.
Current GBM treatments (surgery, radiation, chemotherapy, and steroids) further acidify the microenvironment, promoting tumor recurrence and complications. Restricting glucose and glutamine while increasing non-fermentable, anti-inflammatory ketone bodies can restore pH balance and provide a non-toxic strategy to kill cancer cells.
Combined effects of replacement of sucrose with d-tagatose and addition of different probiotic strains on quality characteristics of chocolate milk
Nowadays, tendency to improve human nutrition and consume new healthful foods such as low-calorie and functional ones has been increased. In this study, effects of ratios of sucrose/d-tagatose (100:0, 0:100, or 50:50) as well as type of commercial probiotic strains (Lactobacillus acidophilus LAFTI L10, Lactobacillus casei LAFTI L26, Lactobacillus rhamnosus HN001, and Bifidobacterium animalis subsp. lactis LAFTI B94) on biochemical and microbiological characteristics, percent of residual sugar, color, and sensory attributes of synbiotic chocolate milk were investigated during 21 days of refrigerated storage (5 °C). The treatments inoculated with L. acidophilus, L. casei, L. rhamnosus, and B. lactis showed significantly higher biochemical and color changes compared to non-probiotic ones. The greatest viability at the end of storage was related to the treatment of d-tagatose with L. rhamnosus (T-R) as well as d-tagatose with L. casei (T-C). Although L. acidophilus, L. casei, and L. rhamnosus mostly tended to ferment d-tagatose, B. lactis did not substantially consume the mentioned sugar. In general, the treatments T-R, ST-R (sucrose and d-tagatose with L. rhamnosus), T-B (d-tagatose with B. lactis), and ST-B (sucrose and d-tagatose with B. lactis) were realized as the best ones in terms of probiotic viability, functional property of d-tagatose, and sensory attributes. In conclusion, d-tagatose could be successfully used as a natural sugar substitute with functional properties for probiotic chocolate milks enhancing their health benefits, but the proper selection of ratio of sucrose/d-tagatose and type of probiotic strain is recommended.
Added sugar and dental caries in children: a scientific update and future steps
This scientific article discusses the strong association between added sugar intake and tooth decay in children in the United States. It emphasizes that sugar-sweetened beverages are the main source of added sugars in children’s diets. While health education is important, it alone is not enough to improve children’s beverage choices. The article highlights the influence of social factors such as socioeconomic disadvantage, household habits, and the availability of sugary products in local stores on added sugar intake. Sociobehavioral interventions, although currently uncommon, show promise in reducing added sugar intake and preventing tooth decay in children. Additionally, upstream approaches like sugar-sweetened beverage bans in schools, warning labels, and taxes can further help reduce excessive added sugar consumption. Although there is a lack of evidence-based clinical strategies, dental health professionals can adopt systematic clinical practices to identify and address excess added sugar intake in pediatric patients. The article calls for more research on sociobehavioral interventions, targeted public health programs for high-risk children, and changes in health policies to address this issue.
Cross-lagged associations between children’s stress and adiposity: the Children’s Body Composition and Stress study
This longitudinal study found that adiposity (body fat) in children is associated with increased stress levels over time. However, stress does not directly cause increases in adiposity. The relationship between stress and adiposity is influenced by cortisol levels and lifestyle factors. These findings highlight the importance of considering multiple factors in obesity prevention programs and the negative impact of unhealthy body composition on children’s well-being.
Consumption of Soft Drinks and Overweight and Obesity Among Adolescents in 107 Countries and Regions
This scientific article examines the relationship between soft drink consumption and the prevalence of overweight and obesity in adolescents. The study analysed data from 107 countries and regions, including a total of 405,528 school-going adolescents. The findings revealed that there was a positive correlation between the prevalence of daily soft drink consumption and the prevalence of overweight and obesity among adolescents. The analysis indicated a statistically significant association between daily soft drink consumption and overweight and obesity in school-going adolescents. The study suggests that reducing soft drink consumption should be a priority in addressing the issue of adolescent overweight and obesity.
Diabetics with COVID-19
High Sugar Levels and COVID-19
Research from Wuhan, China reveals that elevated blood sugar levels in COVID-19 patients without a previous diabetes diagnosis are associated with a more than twofold increase in the risk of death and higher chances of severe complications. The study, published in the journal Diabetologia, examined the relationship between fasting blood glucose levels upon admission and the 28-day mortality of COVID-19 patients without prior diabetes. The results showed that patients with higher blood glucose levels had a significantly higher mortality risk. Men and those with higher pneumonia severity scores also faced a greater risk of death. Additionally, patients with elevated blood glucose levels had a higher likelihood of experiencing complications. The study suggests that acute hyperglycemia may impact the prognosis of hospitalized COVID-19 patients, potentially through changes in coagulation, endothelial function, and the release of inflammatory cytokines. The authors emphasize the importance of blood sugar testing and control for all COVID-19 patients, even if they do not have a pre-existing diabetes diagnosis, to improve treatment outcomes during the pandemic.
A Machine-Generated View of the Role of Blood Glucose Levels in the Severity of COVID-19
SARS-CoV-2, the virus that caused COVID-19, spread rapidly worldwide. Researchers analyzed 240,000 scientific articles and found that elevated blood glucose levels played a significant role in the severity of the disease. The virus exploited high glucose levels to weaken the immune system, enter cells, replicate, and trigger inflammation and damage. Manual review and computational modeling supported this hypothesis. Elevated glucose levels could explain the varying severity of COVID-19 and had implications for diagnostics, treatments, and critical care.
Elevated Glucose Levels Favor SARS-CoV-2 Infection and Monocyte Response through a HIF-1α/Glycolysis-Dependent Axis
It remains unclear why individuals with uncontrolled glucose levels and diabetes are more susceptible to developing the severe form of COVID-19. However, studies have shown that monocytes and macrophages, the most enriched immune cell types in the lungs of COVID-19 patients, undergo metabolic changes that facilitate SARS-CoV-2 replication. These changes involve increased glycolysis mediated by hypoxia-inducible factor-1α (HIF-1α), which inhibits T cell response and reduces epithelial cell survival. Targeting HIF-1α could hold therapeutic potential for the development of novel drugs to treat severe COVID-19.
Tolerance of Human Fibroblasts to Benfo-Oxythiamine In Vitro
This study aimed to investigate the potential application of B-OT in the aspiration tract. An in vitro model was developed to assess the tolerance of primary human gingival fibroblasts to B-OT during mouth-washing simulation. The results showed no adverse effects on the cells even at high concentrations of B-OT (up to 1000 µM). Further testing with continuous exposure to B-OT in medium also demonstrated good tolerance, with minimal effects observed at 10 µM and a slight reduction at 100 µM. These findings support the potential use of B-OT as a mouth-washing solution and nasal spray, highlighting its favorable tolerance by oral cells.
D-Tagatose: A Rare Sugar with Functional Properties and Antimicrobial Potential against Oral Species
D-tagatose, a low-calorie rare sugar, offers significant health benefits, particularly for oral health. With antioxidant and prebiotic properties, it has a low glycaemic impact, supports lipid profile improvement, and shows potential in managing diabetes and obesity. Studies highlight its antibacterial effects, including reducing cariogenic bacteria like S. mutans, inhibiting biofilm formation, and preventing pH decline. D-tagatose also promotes oxidative stress reduction and demonstrates effectiveness as an air-polishing powder for biofilm removal. These attributes position D-tagatose as a promising alternative sugar for preventing systemic diseases and enhancing oral health.
Synbiotic impact of tagatose on viability of Lactobacillus rhamnosus strain GG mediated by the phosphotransferase system (PTS)
Synbiotics, the combination of prebiotics and probiotics, has been shown to produce synergistic effects that promote gastrointestinal well-being of host. Tagatose is a low calorie food ingredient with putative health-promoting benefits. Herein, we investigated its synbiotic impact on the viability of Lactobacillus casei 01 and Lactobacillus rhamnosus strain GG and the potential mechanism involved. Tagatose, as a synbiotic substrate, enhanced the growth of L. casei 01 and L. rhamnosus strain GG compared to other prebiotics. Other gut-indigenous such as Clostridium spp. readily utilized fructooligosaccharide (FOS), the most widely used functional prebiotics, but not tagatose. Additionally, tagatose enhanced probiotic functions of L. casei 01 and L. rhamnosus strain GG by reinforcing their attachment on HT-29 intestine epithelial cells and enhancing their cholesterol-lowering activities. Whole transcriptome study and quantitative real-time polymerase chain reaction (qRT-PCR) test showed that the presence of tagatose in L. rhamnosus strain GG caused induction of a large number of genes associated with carbohydrate metabolism including the phosphotransferase system (PTS). Collectively, these results indicate the tagatose enhanced the growth of L. casei 01 and L. rhamnosus strain GG and their probiotic activities by activating tagatose-associated PTS networks. Importantly, this study highlights the potential application of tagatose and L. casei 01 and/or L. rhamnosus strain GG as a synbiotic partner in functional dairy foods (i.e. yogurt and cheese) and therapeutic dietary supplements.
Disposition of D-[U-14C]tagatose in the rat
The purpose of this experiment was to determine the disposition of D-tagatose, under development as a low-calorie sweetener, in conventional and germ-free male rats. One group of conventional rats was fed a diet containing D-tagatose (100 g/kg) mixed with the nonpurified diet (900 g/kg) for 28 days. Then, [U-14C]-labeled D-tagatose was administered as a single dose (approximately 220-380 kBq) to 4 of these adapted rats, as well as to 15 conventional and germ-free rats with no prior exposure (i.e., unadapted) to D-tagatose. Eleven of the 19 dosed animals (4 adapted conventional, 3 unadapted conventional and 2 unadapted germ-free, all dosed orally, plus 2 unadapted conventional dosed intravenously) were placed in metabolism chambers and samples of CO2, urine, and feces taken at regular intervals. At termination, a complete material balance was obtained based on the recovery of 14C. Over the 6-h digestive period, D-tagatose was metabolized to release 39.9 and 13.9% of the oral dose as CO2 in the adapted conventional rats and in the unadapted germ-free rats, respectively. Total releases approximated 68 and 22%, respectively. The difference in CO2 evolution is ascribed to microbial fermentation of D-tagatose in the gut of the conventional rats. The role of adaptation was confirmed by finding 93% less D-tagatose in the feces of the adapted conventional rat than in the feces of the unadapted conventional rat. The intestinal absorption of D-tagatose in the rat is estimated to be 20%. The results demonstrate that D-tagatose is metabolized primarily by microorganisms in the gut of the rat, with an upper limit between 15 and 20% of oral dose metabolized by the host.
Use of a monosaccharide for sub-and/or supragingival tooth cleaning
The present invention refers to the use of at least one monosaccharide for the preparation of a powder for the sub- and/or supragingival powder jet cleaning of tooth surfaces.
Potent inhibitory effects of D-tagatose on the acid production and water-insoluble glucan synthesis of Streptococcus mutans GS5 in the presence of sucrose
We examined and compared the inhibitory effects of D-tagatose on the growth, acid production, and water-insoluble glucan synthesis of GS5, a bacterial strain of Streptococcus mutans, with those of xylitol, D-psicose, L-psicose and L-tagatose. GS5 was cultured for 12h in a medium containing 10% (w/v) of xylitol, D-psicose, L-psicose, D-tagatose or L-tagatose, and the inhibitory effect of GS5 growth was assessed. Each sugar showed different inhibitory effects on GS5. Both D-tagatose and xylitol significantly inhibited the acid production and water-insoluble glucan synthesis of GS5 in the presence of 1% (w/v) sucrose. However, the inhibitory effect of acid production by D-tagatose was significantly stronger than that of xylitol in presence of sucrose.
D‑Tagatose inhibits the growth and biofilm formation of Streptococcus mutans
Dental caries is an important global health concern and Streptococcus mutans has been established as a major cariogenic bacterial species. Reports indicate that a rare sugar, D‑tagatose, is not easily catabolized by pathogenic bacteria. In the present study, the inhibitory effects of D‑tagatose on the growth and biofilm formation of S. mutans GS‑5 were examined.
Food Labelling: Health Claims; D-tagatose and Dental Caries
The Food and Drug Administration (FDA) is amending the regulation authorizing a health claim on sugar alcohols and dental caries, i.e., tooth decay, to include the sugar D-tagatose, a novel food ingredient. Similar to the sugar alcohols currently listed in § 101.80 (21 CFR 101.80), D-tagatose is a carbohydrate sweetener that is slowly fermented by oral microorganisms, thus producing less acid than more fermentable carbohydrates. We (FDA) are taking this action in response to a petition filed by Arla Foods Ingredients amba.
EFSA-Approved General Function Claim (Commission Regulation (EU) No. 432/2012)
Consumption of foods/ drinks containing D-tagatose instead of sugar contributes to the maintenance of tooth
mineralization.
Use of d-galactose to regulate biofilm growth
This animal study demonstrated the effectiveness of toothpaste made with galactose in preventing biofilm growth: “Our results suggest that d-galactose can be a candidate substance for the development of oral hygiene products to prevent caries by inhibiting the biofilm formation of S. mutans”
Potential of Prebiotic D-Tagatose for Prevention of Oral Disease
This study explores the effects of D-tagatose, a sugar found in the saliva of individuals with good oral hygiene, on three key oral bacteria: Streptococcus oralis, Streptococcus mutans, and Streptococcus gordonii. It was found that higher levels of salivary D-tagatose are linked to lower dental biofilm. When D-tagatose was the only carbohydrate available, S. mutans and S. gordonii showed minimal biofilm formation, while S. oralis formed significant biofilms. Additionally, D-tagatose suppressed the growth of S. mutans and S. gordonii even in the presence of glucose, but had no inhibitory effect on S. oralis. This suggests that D-tagatose may interfere with glycolysis and downstream metabolism, specifically in the pathogenic bacteria. The study concludes that D-tagatose, due to its selective action against harmful oral bacteria while sparing beneficial ones, could be a promising oral prebiotic to improve oral health.
Anticaries effectiveness of D(+)-galactose
This study shows the effectiveness of galactose to prevent cavities and improve oral health: “5.0% galactose reduces the amount of caries with a high significance level, lowers abrasion of the chewing surfaces, possibly because of increased serum calcium related to this galactose concentration, and diminishes the amount of film.”
Removal and prevention of dental plaque with d-tagatose
The International Journal of Cosmetic Science published a study on removing and preventing dental plaque with tagatose.
The development of dental plaque involves the adherence of early and late bacterial colonizers to form a biofilm. In this study, researchers examined 15 oral isolates representing both early and late colonizers and tested their ability to coaggregate. They found that d-tagatose, a component of a toothpaste, effectively reversed coaggregation among these bacteria. d-Tagatose demonstrated a high success rate in reversing coaggregation, particularly among the late colonizers associated with periodontal diseases. This suggests that d-tagatose has the potential to prevent plaque development and modify the subgingival microbiota, providing a conservative approach to control gingival and periodontal diseases.
Food labeling: health claims; D-tagatose and dental caries. Final rule.
The FDA has finalized a rule that includes the sugar D-tagatose as an eligible substance for the dental caries health claim. This completes the rulemaking process that began with the interim final rule.
Virulence factors of Streptococcus mutans and dental caries prevention
Streptococcus mutans is a microorganism known for its ability to adhere to tooth surfaces and produce acids, which contribute to tooth decay. The synthesis of insoluble glucan from sucrose by S. mutans is crucial for its adherence. In this report, we discuss our recent findings on the virulence factors of S. mutans and potential methods for preventing dental caries caused by this microorganism.
Evaluation of a model for short-term clinical testing of cariogenicity
This study examined caries-like alterations on the teeth of 60 panelists using conventional and laser methods. Subjects consumed different candies or served as controls. After five days without oral hygiene, all groups showed increased caries-like changes, with no significant differences between them. The laser method consistently yielded higher scores. These findings emphasize the need for sensitive quantitative methods in short-term cariogenicity tests involving individuals who use fluorides regularly.
All sugars are not alike: Isomaltulose better than table sugar for type 2 diabetes patients
Like sucrose (table sugar), the natural disaccharide isomaltulose (PalatinoseTM) consists of glucose and fructose, but it is apparently more suitable for people with type 2 diabetes with regard to regulating blood glucose levels. The favorable metabolic effect of isomaltulose is due to the almost opposing release profiles of the gut hormones GLP-1 and GIP, a new study shows.
Novel findings on the metabolic effects of the low glycaemic carbohydrate isomaltulose (Palatinose)
This study included three human intervention trials to investigate the physiological characteristics of isomaltulose (iso). The results showed that iso is effectively absorbed from the small intestine, regardless of the food matrix, and provides a prolonged delivery of blood glucose. It was found to have lower postprandial blood glucose and insulin responses compared to sucrose. Regular consumption of iso within a Western-type diet was well tolerated and did not affect blood lipids in individuals with hyperlipidemia. Although no significant differences were observed compared to sucrose after the 4-week intervention, iso shows promise as a carbohydrate option for individuals at risk of vascular diseases.
The genes and enzymes for the catabolism of galactitol, D-tagatose, and related carbohydrates in Klebsiella oxytoca M5a1 and other enteric bacteria display convergent evolution
Enteric bacteria (Enteriobacteriaceae) carry on their single chromosome about 4000 genes that all strains have in common (referred to here as “obligatory genes”), and up to 1300 “facultative” genes that vary from strain to strain and from species to species. In closely related species, obligatory and facultative genes are orthologous genes that are found at similar loci. We have analyzed a set of facultative genes involved in the degradation of the carbohydrates galactitol, D-tagatose, D-galactosamine and N-acetyl-galactosamine in various pathogenic and non-pathogenic strains of these bacteria. The four carbohydrates are transported into the cell by phosphotransferase (PTS) uptake systems, and are metabolized by closely related or even identical catabolic enzymes via pathways that share several intermediates. In about 60% of Escherichia coli strains the genes for galactitol degradation map to a gat operon at 46.8 min. In strains of Salmonella enterica, Klebsiella pneumoniae and K. oxytoca, the corresponding gat genes, although orthologous to their E. coli counterparts, are found at 70.7 min, clustered in a regulon together with three tag genes for the degradation of D-tagatose, an isomer of D-fructose. In contrast, in all the E. coli strains tested, this chromosomal site was found to be occupied by an aga/kba gene cluster for the degradation of D-galactosamine and N-acetyl-galactosamine. The aga/kba and the tag genes were paralogous either to the gat cluster or to the fru genes for degradation of D-fructose. Finally, in more then 90% of strains of both Klebsiella species, and in about 5% of the E. coli strains, two operons were found at 46.8 min that comprise paralogous genes for catabolism of the isomers D-arabinitol (genes atl or dal) and ribitol (genes rtl or rbt). In these strains gat genes were invariably absent from this location, and they were totally absent in S. enterica. These results strongly indicate that these various gene clusters and metabolic pathways have been subject to convergent evolution among the Enterobacteriaceae. This apparently involved recent horizontal gene transfer and recombination events, as indicated by major chromosomal rearrangements found in their immediate vicinity.
Effects of D-Tagatose on the Growth of Intestinal Microflora and the Fermentation of Yogurt
To investigate the effect of tagatose on the growth of intestinal bacteria, various species were cultivated individually on m-PYF medium containing tagatose as a carbon source. The tagatose inhibited the growth of intestinal harmful microorganisms such as Staphylococcus aureus subsp. aureus, Listeria monocytogenes, Vibrio parahaemolyticus, Salmonella Typhimurium, and Pseudomonas fluorescens. In the case of beneficial microorganisms found in the intestine, Lactobacillus casei grew effectively on m-PYF medium containing tagatose, while Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc citreum, and Lactobacillus acidophilus did not. To examine the effect of tagatose on fermentation by Lactobacillus casei, yogurt was prepared with tagatose as a carbon source. The resulting acid production stimulated a remarkable growth of lactic acid bacteria in the yogurt. After fermentation for 24 hours, the viable cell count and viscosity of yogurt were above 8.49 log CFU/mL and 1,266 cps, respectively. Moreover, sensory evaluations showed that the yogurt supplemented with tagatose was as acceptable as control yogurt prepared with glucose as a carbon source. The changes in pH, titratable acidity and lactic acid bacteria in yogurt prepared with tagatose did not show any significant changes during storage for 15 days at 4°C.
Effect of L-glucose and D-tagatose on bacterial growth in media and a cooked cured ham product
Cured meats such as ham can undergo premature spoilage on account of the proliferation of lactic acid bacteria. This spoilage is generally evident from a milkiness in the purge of vacuum-packaged sliced ham. Although cured, most hams are at more risk of spoilage than other types of processed meat products because they contain considerably higher concentrations of carbohydrates, approximately 2 to 7%, usually in the form of dextrose and corn syrup solids. Unfortunately, the meat industry is restricted with respect to the choice of preservatives and bactericidal agents. An alternative approach from these chemical compounds would be to use novel carbohydrate sources that are unrecognizable to spoilage bacteria. L-Glucose and D-tagatose are two such potential sugars, and in a series of tests in vitro, the ability of bacteria to utilize each as an energy source was compared to that of D-glucose. Results showed that both L-glucose and D-tagatose are not easily catabolized by a variety of lactic bacteria and not at all by pathogenic bacteria such as Escherichia coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus, and Yersinia enterocolitica. In a separate study, D-glucose, L-glucose, and D-tagatose were added to a chopped and formed ham formulation and the rate of bacterial growth was monitored. Analysis of data by a general linear model revealed that the growth rates of total aerobic and lactic acid bacteria were significantly (P < 0.05) slower for the formulation containing D-tagatose than those containing L- or D-glucose. Levels of Enterobacteriaceae were initially low and these bacteria did not significantly (P < 0.20) change in the presence of any of the sugars used in the meat formulations. Compared to the control sample containing D-glucose, the shelf life of the chopped and formed ham containing D-tagatose at 10 degrees C was extended by 7 to 10 days. These results indicate that D-tagatose could deter the growth of microorganisms and inhibit the rate of spoilage in a meat product containing carbohydrates.
Naturally occurring rare sugars are free radical scavengers and can ameliorate endoplasmic reticulum stress
Because of potential use of naturally occurring rare sugars as sweeteners, their effect on superoxide (SO), hydroxyl and peroxyl radicals and endoplasmic reticulum (ER) stress was examined in human coronary artery endothelial cells. SO generation was measured using the superoxide-reactive probe 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo[1,2-A]pyrazin-3-one hydrochloride chemiluminescence. Phycoerythrin fluorescence based assay was used to monitor scavenging activity of sugars in the presence of hydroxyl or peroxyl radical generators [CuSO4 and azobis (2 amidinopropane) hydrochloride respectively]. Measurements were made in relative light units (RLU). ER stress was measured with an ER stress-sensitive secreted alkaline phosphatase (SAP) assay and by Western blot analysis of the expression and phosphorylation of key proteins in the unfolded protein response, namely CHOP47, eIF2α and JNK1. D-Glucose (27.5 mM) increased SO generation (5536 ± 283 vs. 2963 ± 205 RLU in controls; p < 0.0007) and decreased SAP secretion (73411 ± 3971 vs. 101749 ± 7652 RLU in controls; p < 0.005) indicating ER stress. Treatment of cells with 5.5 or 27.5 mM of D-allulose, D-allose, D-sorbose and D-tagatose reduced SO generation (all p < 0.05). This could not be attributed to inhibition of cellular uptake of dextrose by the rare sugars tested. In a cell free system, all four rare sugars had significantly more SO, hydroxyl and peroxyl radical scavenging activity compared to dextrose (all p < 0.01). Treatment of cells with rare sugars reduced ER stress. However, unlike other three rare sugars, D-sorbose did not inhibit tunicamycin-induced eIF2α phosphorylation. Naturally occurring rare sugars are free radical scavengers and can reduce ER stress.
Antioxidant and cytoprotective properties of D-tagatose in cultured murine hepatocytes
D-Tagatose is a zero-energy producing ketohexose that is a powerful cytoprotective agent against chemically induced cell injury. To further explore the underlying mechanisms of cytoprotection, we investigated the effects of D-tagatose on both the generation of superoxide anion radicals and the consequences of oxidative stress driven by prooxidant compounds in intact cells. Primary cultures of hepatocytes derived from male C57BL/6 mice were exposed to the redox cycling drug nitrofurantoin (NFT). Lethal cell injury induced by 300 microM NFT was completely prevented by high concentrations (20 mM) of D-tagatose, whereas equimolar concentrations of glucose, mannitol, or xylose were ineffective. The extent of NFT-induced intracellular superoxide anion radical formation was not altered by D-tagatose, indicating that the ketohexose did not inhibit the reductive bioactivation of NFT. However, the NFT-induced decline of the intracellular GSH content was largely prevented by D-tagatose. The sugar also afforded complete protection against NFT toxicity in hepatocytes that had been chemically depleted of GSH. Furthermore, the ketohexose fully protected from increases in both membrane lipid peroxidation and protein carbonyl formation. In addition, D-tagatose completely prevented oxidative cell injury inflicted by toxic iron overload with ferric nitrilotriacetate (100 microM). In contrast, D-tagatose did not protect against lethal cell injury induced by tert-butyl hydroperoxide, a prooxidant which acts by hydroxyl radical-independent mechanisms and which is partitioned in the lipid bilayer. These results indicate that D-tagatose, which is a weak iron chelator, can antagonize the iron-dependent toxic consequences of intracellular oxidative stress in hepatocytes. The antioxidant properties of D-tagatose may result from sequestering the redox-active iron, thereby protecting more critical targets from the damaging potential of hydroxyl radical.
90-Day oral toxicity study of D-tagatose in rats
D-tagatose is a ketohexose, tastes like sugar and is useful as a low-calorie sweetener. To assess D-tagatose’s safety, an oral 90-day toxicity study was conducted on male and female Crl:CDBR rats at dietary doses of 5, 10, 15, and 20% D-tagatose. One control group (dietary control) received only lab chow; a second control group received 20% cellulose/fructose in the diet. There were no treatment-related effects at 5% D-tagatose in the diet. At higher doses, treatment-related effects included transient soft stools in male and female animals from the 15 and 20% dose groups. This was anticipated as a result of the osmotic effect of a large dose of relatively undigested sugar and was not considered a toxic effect. All treatment groups gained weight over the study period; however, mean body weights were statistically significantly decreased in the 15 and 20% dose-group males and the 20% dose-group females at selected intervals compared to dietary control animals. No significant reduction in mean food consumption was noted in the treatment groups compared to the dietary control. Statistically significantly increased relative liver weights were noted in male and female animals from the 10, 15, and 20% dose groups compared to the dietary control. No gross pathological findings correlated with these increased liver weights. Minimal hepatocellular hypertrophy was observed in male and female animals from the 15 and 20% dose groups. An independent review of the liver slides concluded that histomorphologic changes associated with D-tagatose were restricted hepatocyte hypertrophy and hepatocyte glycogen accumulation. Therefore, it was concluded that increased liver weights and minimal hypertrophy were the result of adaptation to the high dietary levels (greater than 5% in the diet) of D-tagatose. No adverse effects were seen at 5% D-tagatose in the diet.
The acute effect of D-tagatose on food intake in human subjects
A double-blind randomized crossover study was performed with nineteen normal-weight men to investigate the effect on subsequent ad libitum food intake of replacing 29 g sucrose with 29 g D-tagatose as sweetener to a breakfast meal. D-Tagatose is a malabsorbed stereoisomer of fructose with potential application as a bulk sweetener. Food intake was measured at lunch offered 4 h after the breakfast meal, during the afternoon with access to abundant snacks, and finally at a supper buffet 9 h after the breakfast. Energy intake at lunch and during the snacking period was similar after ingesting the two sugars, while it was 15% lower after ingesting D-tagatose than with sucrose at supper (P < 0.05). Gastrointestinal factors such as the osmotic effects of unabsorbed D-tagatose causing distension of the gut might have mediated the acute appetite-suppressing effect. The present paper also refers to data from a preceding study in which we observed an increased self-reported energy intake after ingestion of D-tagatose compared with sucrose which, in fact, suggests a relative hyperphagic effect of D-tagatose. However, self-reported food intake may be biased by selective under-reporting and this subsequent study with a more controlled assessment of food intake was therefore conducted. This present study did not support any hyperphagic effect of D-tagatose, but rather suggests that D-tagatose may contribute to a reduced energy intake.
DDDAS Design of Drug Interventions for the Treatment of Dyslipidemia in ApoE-/- Mice
Computational models of complex systems, such as signaling networks and biological systems, can be used to explain the behavior of such systems under various conditions. The large number of integrated processes and variables, and the nonlinearities inherent in the fundamental processes, make it difficult for scientists unassisted by computer simulations to effectively predict the consequences of a particular intervention. For this reason, computer simulation has become an important tool for generating hypotheses about the behavior of these systems that can then be tested in the laboratory and clinic. A dynamic data-driven application simulation (DDDAS) was designed by Biospherics to model complex metabolic disease pathways by testing potential binary therapies in simulations at various combinations of two points in the pathways. Since DDDAS chooses the most effective pair-wise combinations, this data-driven system allows for the implementation of real-time data to model or predict a measurement or event. By incorporating data dynamically rather than statically, the predictions and measurements become more reliable. Dyslipidemia, a common precursor to atherosclerosis, can be manifested by high triglycerides, increased apolipoprotein (Apo) B, high levels of LDL, and low levels of HDL. SPX106 and D-tagatose is a combination drug therapy composed of a carbohydrate (D-tagatose) and SPX106. D-tagatose has been studied for the treatment of diabetes for several years, and has the ability to lower blood insulin levels and to decrease glycogen formation. SPX106 is a natural substance that accelerates lipid catabolism and inhibits dyslipidemia. In apolipoprotein E knockout mice (ApoE-/-), this drug combination has been shown to significantly lower both the amount of atherosclerosis and blood cholesterol levels. This study used 26 male ApoE-/- mice (n=13 in each group, control and treated). The control group received the normal “Western” diet (Harlan TD88137) and the treatment group received a modified version in which the sucrose was replaced with D-tagatose and 1g of SPX106 was added for every kilogram of chow. Mice were fed the diet for 8 weeks and then sacrificed via cardiac puncture. Blood serum was analyzed for cholesterol concentration. A significant difference was observed between the control and treated groups for total cholesterol levels. FPLC separations were done on fractions from both control and treated groups. A significant difference between VLDL and HDL levels was found between the treated and control mice (p<0.05 for both). Aortas were also taken and preserved in formalin to be quantified for atherosclerosis. Aortic sinuses were frozen in OCT and sectioned using a cryostat and then quantified for atherosclerosis. Treated mice showed statistically significant reduction in atherosclerosis in the aortic arch (p<0.01), the thoracic aorta (p<0.05), and the aortic sinus (p<0.05) as well as a reduction of cholesterol (p<0.05).
BSN723T Prevents Atherosclerosis and Weight Gain in ApoE Knockout Mice Fed a Western Diet
This study tests the hypothesis that BSN723T can prevent the development of hyperlipidemia and atherosclerosis in ApoE-/- knockout mice fed a Western (high fat, high cholesterol, and high sucrose) diet. BSN723T is a combination drug therapy consisting of D-tagatose and dihydromyricetin (BSN723). D-tagatose has an antihyperglycemic effect in animal and human studies and shows promise as a treatment for type 2 diabetes and obesity. Many claims regarding BSN723’s pharmacological activities have been made including anti-cancer, anti-diabetic, anti-hypertensive, anti-inflammatory, and anti-atherosclerotic effects. To our knowledge this is the first study that combines D-tagatose and BSN723 for the treatment of hyperlipidemia and the prevention of atherosclerosis.ApoE-deficient mice were randomized into five groups with equivalent mean body weights. The mice were given the following diets for 8 weeks: Group 1 – Standard diet; Group 2 – Western diet; Group 3 – Western diet formulated with D-tagatose; Group 4 – Western diet formulated with BSN723; Group 5 – Western diet formulated with BSN723T. Mice were measured for weight gain, tissue and organ weights, total serum cholesterol and triglycerides and formation of atherosclerosis.The addition of D-tagatose, either alone or in combination with BSN723, prevented the increase in adipose tissue and weight gain brought on by the Western diet. Both D-tagatose and BSN723 alone reduced total cholesterol and the formation of atherosclerosis in the aorta compared to mice on the Western diet. Addition of BSN723 to D-tagatose (BSN723T) did not increase efficacy in prevention of increases in cholesterol or atherosclerosis compared to D-tagatose alone. Addition of either D-tagatose or BSN723 alone to a Western diet prevented weight gain, increases in total serum cholesterol and triglycerides, and the formation of atherosclerosis. However, there was no additive or synergistic effect on the measured parameters with the combination BSN723T treatment.
Combined effects of replacement of sucrose with d-tagatose and addition of different probiotic strains on quality characteristics of chocolate milk
Nowadays, tendency to improve human nutrition and consume new healthful foods such as low-calorie and functional ones has been increased. In this study, effects of ratios of sucrose/d-tagatose (100:0, 0:100, or 50:50) as well as type of commercial probiotic strains (Lactobacillus acidophilus LAFTI L10, Lactobacillus casei LAFTI L26, Lactobacillus rhamnosus HN001, and Bifidobacterium animalis subsp. lactis LAFTI B94) on biochemical and microbiological characteristics, percent of residual sugar, color, and sensory attributes of synbiotic chocolate milk were investigated during 21 days of refrigerated storage (5 °C). The treatments inoculated with L. acidophilus, L. casei, L. rhamnosus, and B. lactis showed significantly higher biochemical and color changes compared to non-probiotic ones. The greatest viability at the end of storage was related to the treatment of d-tagatose with L. rhamnosus (T-R) as well as d-tagatose with L. casei (T-C). Although L. acidophilus, L. casei, and L. rhamnosus mostly tended to ferment d-tagatose, B. lactis did not substantially consume the mentioned sugar. In general, the treatments T-R, ST-R (sucrose and d-tagatose with L. rhamnosus), T-B (d-tagatose with B. lactis), and ST-B (sucrose and d-tagatose with B. lactis) were realized as the best ones in terms of probiotic viability, functional property of d-tagatose, and sensory attributes. In conclusion, d-tagatose could be successfully used as a natural sugar substitute with functional properties for probiotic chocolate milks enhancing their health benefits, but the proper selection of ratio of sucrose/d-tagatose and type of probiotic strain is recommended.
Synbiotic impact of tagatose on viability of Lactobacillus rhamnosus strain GG mediated by the phosphotransferase system (PTS)
Synbiotics, the combination of prebiotics and probiotics, has been shown to produce synergistic effects that promote gastrointestinal well-being of host. Tagatose is a low calorie food ingredient with putative health-promoting benefits. Herein, we investigated its synbiotic impact on the viability of Lactobacillus casei 01 and Lactobacillus rhamnosus strain GG and the potential mechanism involved. Tagatose, as a synbiotic substrate, enhanced the growth of L. casei 01 and L. rhamnosus strain GG compared to other prebiotics. Other gut-indigenous such as Clostridium spp. readily utilized fructooligosaccharide (FOS), the most widely used functional prebiotics, but not tagatose. Additionally, tagatose enhanced probiotic functions of L. casei 01 and L. rhamnosus strain GG by reinforcing their attachment on HT-29 intestine epithelial cells and enhancing their cholesterol-lowering activities. Whole transcriptome study and quantitative real-time polymerase chain reaction (qRT-PCR) test showed that the presence of tagatose in L. rhamnosus strain GG caused induction of a large number of genes associated with carbohydrate metabolism including the phosphotransferase system (PTS). Collectively, these results indicate the tagatose enhanced the growth of L. casei 01 and L. rhamnosus strain GG and their probiotic activities by activating tagatose-associated PTS networks. Importantly, this study highlights the potential application of tagatose and L. casei 01 and/or L. rhamnosus strain GG as a synbiotic partner in functional dairy foods (i.e. yogurt and cheese) and therapeutic dietary supplements.
Disposition of D-[U-14C]tagatose in the rat
The purpose of this experiment was to determine the disposition of D-tagatose, under development as a low-calorie sweetener, in conventional and germ-free male rats. One group of conventional rats was fed a diet containing D-tagatose (100 g/kg) mixed with the nonpurified diet (900 g/kg) for 28 days. Then, [U-14C]-labeled D-tagatose was administered as a single dose (approximately 220-380 kBq) to 4 of these adapted rats, as well as to 15 conventional and germ-free rats with no prior exposure (i.e., unadapted) to D-tagatose. Eleven of the 19 dosed animals (4 adapted conventional, 3 unadapted conventional and 2 unadapted germ-free, all dosed orally, plus 2 unadapted conventional dosed intravenously) were placed in metabolism chambers and samples of CO2, urine, and feces taken at regular intervals. At termination, a complete material balance was obtained based on the recovery of 14C. Over the 6-h digestive period, D-tagatose was metabolized to release 39.9 and 13.9% of the oral dose as CO2 in the adapted conventional rats and in the unadapted germ-free rats, respectively. Total releases approximated 68 and 22%, respectively. The difference in CO2 evolution is ascribed to microbial fermentation of D-tagatose in the gut of the conventional rats. The role of adaptation was confirmed by finding 93% less D-tagatose in the feces of the adapted conventional rat than in the feces of the unadapted conventional rat. The intestinal absorption of D-tagatose in the rat is estimated to be 20%. The results demonstrate that D-tagatose is metabolized primarily by microorganisms in the gut of the rat, with an upper limit between 15 and 20% of oral dose metabolized by the host.
Small-bowel absorption of D-tagatose and related effects on carbohydrate digestibility: an ileostomy study
The ketohexose D-tagatose is a new sweetener with a low energy content. This low energy content may be due to either low absorption of the D-tagatose or decreased absorption of other nutrients.The aims of this study were to measure the excretion of D-tagatose from the human small bowel, to calculate the apparent absorption of D-tagatose, and to study the effects of D-tagatose on the small-bowel excretion of other carbohydrates.A controlled diet was served for 2 periods of 2 d during 3 consecutive weeks to 6 ileostomy subjects. In one of the periods, 15 g D-tagatose was added to the diet daily. Duplicate portions of the diet and ileostomy effluents were freeze-dried and analyzed to calculate the apparent net absorption of D-tagatose and carbohydrates.Median D-tagatose excretion was 19% (range: 12-31%), which corresponded to a calculated apparent absorption of 81% (69-88%). Of the total amount of D-tagatose excreted [2.8 g (1.7-4.4 g)], 60% (8-88%) was excreted within 3 h. Between 3 and 5 h, 32% (11-82%) was excreted. Excretion of wet matter increased by 41% (24-52%) with D-tagatose ingestion. Sucrose and D-glucose excretion increased to a small extent, whereas no significant changes were found in the excretion of dry matter, energy, starch, or D-fructose.The apparent absorption of 15 g D-tagatose/d was 81%. D-Tagatose had only a minor influence on the apparent absorption of other nutrients.
Glycogen synthase activation by sugars in isolated hepatocytes
We have investigated the activation by sugars of glycogen synthase in relation to (i) phosphorylase a activity and (ii) changes in the intracellular concentration of glucose 6-phosphate and adenine nucleotides. All the sugars tested in this work present the common denominator of activating glycogen synthase. On the other hand, phosphorylase a activity is decreased by mannose and glucose, unchanged by galactose and xylitol, and increased by tagatose, glyceraldehyde, and fructose. Dihydroxyacetone exerts a biphasic effect on phosphorylase. These findings provide additional evidence proving that glycogen synthase can be activated regardless of the levels of phosphorylase a, clearly establishing that a nonsequential mechanism for the activation of glycogen synthase occurs in liver cells. The glycogen synthase activation state is related to the concentrations of glucose 6-phosphate and adenine nucleotides. In this respect, tagatose, glyceraldehyde, and fructose deplete ATP and increase AMP contents, whereas glucose, mannose, galactose, xylitol, and dihydroxyacetone do not alter the concentration of these nucleotides. In addition, all these sugars, except glyceraldehyde, increase the intracellular content of glucose 6-phosphate. The activation of glycogen synthase by sugars is reflected in decreases on both kinetic constants of the enzyme, M0.5 (for glucose 6-phosphate) and S0.5 (for UDP-glucose). We propose that hepatocyte glycogen synthase is activated by monosaccharides by a mechanism triggered by changes in glucose 6-phosphate and adenine nucleotide concentrations which have been described to modify glycogen synthase phosphatase activity. This mechanism represents a metabolite control of the sugar-induced activation of hepatocyte glycogen synthase.
Effect of diets containing sucrose vs. D-tagatose in hypercholesterolemic mice
Effects of functional sweeteners on the development of the metabolic syndrome and atherosclerosis are unknown. The objective was to compare the effect of dietary carbohydrate in the form of sucrose (SUCR) to D-tagatose (TAG; an isomer of fructose currently used as a low-calorie sweetener) on body weight, blood cholesterol concentrations, hyperglycemia, and atherosclerosis in low-density lipoprotein receptor deficient (LDLr(-/-)) mice. LDLr(-/-) male and female mice were fed either standard murine diet or a diet enriched with TAG or SUCR as carbohydrate sources for 16 weeks. TAG and SUCR diets contained equivalent amounts (g/kg) of protein, fat, and carbohydrate. We measured food intake, body weight, adipocyte diameter, serum cholesterol and lipoprotein concentrations, and aortic atherosclerosis. Macrophage immunostaining and collagen content were examined in aortic root lesions. CONTROL and TAG-fed mice exhibited similar energy intake, body weights and blood glucose and insulin concentrations, but SUCR-fed mice exhibited increased energy intake and became obese and hyperglycemic. Adipocyte diameter increased in female SUCR-fed mice compared to TAG and CONTROL. Male and female SUCR-fed mice had increased serum cholesterol and triglyceride concentrations compared to TAG and CONTROL. Atherosclerosis was increased in SUCR-fed mice of both genders compared to TAG and CONTROL. Lesions from SUCR-fed mice exhibited pronounced macrophage immunostaining and reductions in collagen content compared to TAG and CONTROL mice. These results demonstrate that in comparison to sucrose, equivalent substitution of TAG as dietary carbohydrate does not result in the same extent of obesity, hyperglycemia, hyperlipidemia, and atherosclerosis.
Effects of different sweet preloads on incretin hormone secretion, gastric emptying, and postprandial glycemia in healthy humans
Macronutrient “preloads” can stimulate glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), slow gastric emptying, and reduce postprandial glycemic excursions. After sweet preloads, these effects may be signaled by sodium-glucose cotransporter-1 (SGLT1), sweet taste receptors, or both. We determined the effects of 4 sweet preloads on GIP and GLP-1 release, gastric emptying, and postprandial glycemia.
Beneficial effect of tagatose consumption on postprandial hyperglycemia in Koreans: a double-blind crossover designed study
The present study determined the effect of tagatose supplementation on postprandial hyperglycemia in normal (n = 54) and hyperglycemic subjects [n = 40, impaired fasting glucose (IFG) and newly diagnosed type 2 diabetes]. In a double-blind crossover designed study, study subjects were randomly assigned to consume a sucralose-erythritol drink (the placebo) or a tagatose-containing drink (the test) with a seven-day interval. Finally, 85 subjects completed the study (normal, n = 52; hyperglycemic, n = 33). Blood samples were collected at 0, 30, 60 and 120 min after ingestion and analyzed for fasting and postprandial levels of glucose, insulin and C-peptide. Basic anthropometric parameters and lipid files were also measured. Hyperglycemic subjects were basically older and heavier, and showed higher levels of triglyceride, total- and LDL-cholesterols and apolipoprotein AI and B compared with normal subjects. After consuming the tagatose (5 g)-containing drink, hyperglycemic subjects had a significant reduction in serum levels of glucose at 120 min (p = 0.019) and glucose area under the curve (AUC) (p = 0.017), however these were not observed in normal subjects. When ages were matched between the two groups, the glucose response patterns were shown to be similar. Additionally, normal subjects who received a high-dose of tagatose-containing drinks (10 g) showed significantly lower levels of insulin at 30 min (p = 0.004) and 60 min (p = 0.011), insulin AUC (p = 0.009), and C-peptide at 30 min (p = 0.004), 60 min (p = 0.011) and C-peptide AUC (p = 0.023). In conclusion, a single dietary supplement in the form of a tagatose-containing drink may be beneficial for controlling postprandial glycemic response in Koreans.
D-tagatose, a novel hexose: acute effects on carbohydrate tolerance in subjects with and without type 2 diabetes
D-Tagatose (D-tag), a hexose bulk sweetener, does not affect plasma glucose levels when orally administered to rodents. Additionally, D-tag attenuates the rise in plasma glucose after mice are administered oral sucrose. The current study was undertaken to investigate the acute glycaemic effects of oral D-tag alone or in combination with oral glucose in human subjects with and without type 2 diabetes mellitus. Glycaemic responses to D-tag also were investigated in subjects after oral sucrose to examine whether the glucose-lowering effects of D-tag in rodents may result from a direct inhibition of intestinal disaccharidases.
Effects of acute and repeated oral doses of D-tagatose on plasma uric acid in normal and diabetic humans
D-tagatose, a stereoisomer of D-fructose, is a naturally occurring ketohexose proposed for use as a low-calorie bulk sweetener. Ingested D-tagatose appears to be poorly absorbed. The absorbed portion is metabolized in the liver by a pathway similar to that of D-fructose. The main purpose of this study was to determine if acute or repeated oral doses of D-tagatose would cause elevations in plasma uric acid (as is seen with fructose) in normal humans and Type 2 diabetics.
Reduced Susceptibility to Sugar-Induced Metabolic Derangements and Impairments of Myocardial Redox Signalling in Mice Chronically Fed with D-Tagatose when Compared to Fructose
D-tagatose is an isomer of fructose and is ~90% as sweet as sucrose with less caloric value. Nowadays, D-tagatose is used as a nutritive or low-calorie sweetener. Despite clinical findings suggesting that D-tagatose could be beneficial in subjects with type 2 diabetes, there are no experimental data comparing D-tagatose with fructose, in terms of metabolic derangements and related molecular mechanisms evoked by chronic exposure to these two monosaccharides.C57Bl/6j mice were fed with a control diet plus water (CD), a control diet plus 30% fructose syrup (L-Fr), a 30% fructose solid diet plus water (S-Fr), a control diet plus 30% D-tagatose syrup (L-Tg), or a 30% D-tagatose solid diet plus water (S-Tg), during 24 weeks.Both solid and liquid fructose feeding led to increased body weight, abnormal systemic glucose homeostasis, and an altered lipid profile. These effects were associated with vigorous increase in oxidative markers. None of these metabolic abnormalities were detected when mice were fed with both the solid and liquid D-tagatose diets, either at the systemic or at the local level. Interestingly, both fructose formulations led to significant Advanced Glycation End Products (AGEs) accumulation in mouse hearts, as well as a robust increase in both myocardial AGE receptor (RAGE) expression and NF-κB activation. In contrast, no toxicological effects were shown in hearts of mice chronically exposed to liquid or solid D-tagatose.Our results clearly suggest that chronic overconsumption of D-tagatose in both formulations, liquid or solid, does not exert the same deleterious metabolic derangements evoked by fructose administration, due to differences in carbohydrate interference with selective proinflammatory and oxidative stress cascades.
D-tagatose, a stereoisomer of D-fructose, increases blood uric acid concentration
D-Fructose has been found to increase uric acid production by accelerating the degradation of purine nucleotides, probably due to hepatocellular depletion of inorganic phosphate (Pi) by an accumulation of ketohexose-1-phosphate. The hyperuricemic effect of D-tagatose, a stereoisomer of D-fructose, may be greater than that of D-fructose, as the subsequent degradation of D-tagatose-1-phosphate is slower than the degradation of D-fructose-1-phosphate. We tested the effect of 30 g oral D-tagatose versus D-fructose on plasma uric acid and other metabolic parameters in 8 male subjects by a double-blind crossover design. Both the peak concentration and 4-hour area under the curve (AUC) of serum uric acid were significantly higher after D-tagatose compared with either 30 g D-fructose or plain water. The decline in serum Pi concentration was greater at 50 minutes after D-tagatose versus D-fructose. The thermogenic and lactacidemic responses to D-tagatose were blunted compared with D-fructose. D-Tagatose attenuated the glycemic and insulinemic responses to a meal that was consumed 255 minutes after its administration. Moreover, both fructose and D-tagatose increased plasma concentrations of cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1). The metabolic effects of D-tagatose occurred despite its putative poor absorption.
D-Tagatose, a stereoisomer of D-fructose, increases hydrogen production in humans without affecting 24-hour energy expenditure or respiratory exchange ratio
In growth studies on rats, the ketohexose D-tagatose has been shown to contribute no net metabolizable energy, and a pronounced thermic effect of the sugar has been suggested to account for the absence of energy. In a double-blind and balanced cross-over design, we measured 24-h energy expenditure in eight normal weight humans in a respiration chamber during the consumption of 30 g D-tagatose or 30 g sucrose/d. Metabolic measurements were performed before and after a 2-wk adaptation period with a 30-g daily intake of the test sugar. Total 24-h energy expenditure and hour-by-hour profile were unaffected by the test sugar. The nonprotein respiratory exchange ratio (RERnp) was similar during consumption of D-tagatose and sucrose. However, the effect on RERnp due to CO2 produced by fermentation of D-tagatose could not be quantified in this study. A significant increase in 24-h H2 production (35%) during D-tagatose administration suggests a substantial malabsorption of the sugar. We found no effects of the 2-wk adaptation period on the measured gas exchange variables. Significantly lower fasting plasma insulin and triglyceride concentrations were observed during D-tagatose administration compared with the sucrose period. No effects of D-tagatose on body weight and composition were seen, but the perception of fullness 2.5 h after the sugar load was greater with D-tagatose. In conclusion, this study does not suggest a pronounced thermic effect of D-tagatose, and other mechanisms seem to be required to explain its lack of net energy.
Effect of oral D-tagatose on liver volume and hepatic glycogen accumulation in healthy male volunteers
Standard toxicity tests with high levels of D-tagatose showed a reversible enlargement of the liver in Sprague-Dawley rats without increase of liver enzymes. The present study tests the hypotheses that partial substitution of dietary sucrose by D-tagatose for 28 days increases the volume of human liver and the concentration of liver glycogen. Twelve healthy, male volunteers were studied in a double-blind crossover study with ingestion of D-tagatose (3×15 g daily) and placebo (sucrose, 3×15 g daily) for periods of 28 days each. Liver volume and glycogen concentration have been determined by magnetic resonance (MR) imaging and spectroscopy, which were accompanied by routine medical examinations. MR examinations before and after the treatments revealed no effects (P>0.05) of treatment, period, or subject for changes in liver volume or glycogen concentration. A steady increase of liver volumes, independent of the D-tagatose or placebo intake, has been observed over the study in parallel with a slight increase in body weight. The treatment with D-tagatose was not associated with clinically relevant changes of the examined clinico-chemical and hematological parameters, including liver enzymes and uric acid.
The Role of the Pentose Phosphate Pathway in Diabetes and Cancer
T2DM is a chronic metabolic disease featured by persistently abnormal hyperglycemia, which can cause serious chronic damage to kidneys, eyes, and nerves. Deregulated insulin secretion and progressive insulin resistance are two main characteristics of T2DM (6). Over the past few decades, studies on the pathogenesis of T2DM have revealed a close relationship between the PPP, obesity-related insulin resistance and T2DM. In this part, we will mainly focus on the role of the PPP in obesity-related insulin resistance, insulin secretion and chronic diabetic complications.
Mortality and other important diabetes-related outcomes with insulin vs other antihyperglycemic therapies in type 2 diabetes
In people with T2DM, exogenous insulin therapy was associated with an increased risk of diabetes-related complications, cancer, and all-cause mortality. Differences in baseline characteristics between treatment groups should be considered when interpreting these results.
Insulin use and increased risk of mortality in type 2 diabetes: a cohort study
We observed a significant and graded association between mortality risk and insulin exposure level in an inception cohort of patients with type 2 diabetes that persisted despite multivariable adjustment.
Transketolase promotes MAFLD by limiting inosine-induced mitochondrial activity
Metabolic dysfunction-associated fatty liver disease (MAFLD) has a global prevalence of about 25% and no approved therapy. Using metabolomic and proteomic analyses, we identified high expression of hepatic transketolase (TKT), a metabolic enzyme of the pentose phosphate pathway, in human and mouse MAFLD. Hyperinsulinemia promoted TKT expression through the insulin receptor-CCAAT/enhancer-binding protein alpha axis. Utilizing liver-specific TKT overexpression and knockout mouse models, we demonstrated that TKT was sufficient and required for MAFLD progression. Further metabolic flux analysis revealed that Tkt deletion increased hepatic inosine levels to activate the protein kinase A-cAMP response element binding protein cascade, promote phosphatidylcholine synthesis, and improve mitochondrial function. Moreover, insulin induced hepatic TKT to limit inosine-dependent mitochondrial activity. Importantly, N-acetylgalactosamine (GalNAc)-siRNA conjugates targeting hepatic TKT showed promising therapeutic effects on mouse MAFLD. Our study uncovers how hyperinsulinemia regulates TKT-orchestrated inosine metabolism and mitochondrial function and provides a novel therapeutic strategy for MAFLD prevention and treatment.
Erythritol is a pentose-phosphate pathway metabolite and associated with adiposity gain in young adults
This study investigated metabolomic markers associated with the development of central adiposity in young adults. Participants with incident central adiposity gain had higher levels of blood erythritol compared to those with stable adiposity. Participants with higher baseline hemoglobin A1c (HbA1c) levels also had significantly higher blood erythritol. Erythritol was found to be synthesized from glucose through the pentose-phosphate pathway, suggesting its potential role in the association between erythritol and obesity in young adults.
Letter Regarding Article, “Metabolomic Pattern Predicts Incident Coronary Heart Disease”
This article discusses the use of erythritol, a metabolite, as a predictive marker for coronary heart disease. Erythritol is a naturally occurring noncaloric sweetener and not an artificial sweetener. The presence of erythritol in blood samples cannot be explained by its consumption as a sugar replacement. Studies have shown an association between erythritol levels and impaired glycemic control and central adiposity. The conversion of glucose to erythritol via the pentose-phosphate pathway may play a role in reflecting impaired glycemic control and its related complications. Further research is needed to fully understand the connection between erythritol concentrations and these health conditions.
Diabetes UK
Sucrose Intake Elevates Erythritol in Plasma and Urine in Male Mice
This study investigated the impact of diet and genetic factors on erythritol levels in mice, a biomarker linked to diabetes and cardiovascular issues. Researchers fed mice different diets (low-fat or high-fat) and provided them with either plain water or sucrose water. They measured erythritol concentrations in blood, urine, and tissues. The study found that dietary sucrose significantly increased erythritol levels, regardless of the mice’s diet. The presence or absence of certain enzymes (SORD and ADH1) did not significantly influence plasma erythritol levels, but mice lacking the SORD enzyme had lower kidney erythritol content when fed sucrose.
Effect of chronic exposure to ketohexoses on pancreatic β-cell function in INS-1 rat insulinoma cells
This study examines the impact of various rare sugars on pancreatic β-cells, specifically in the context of type 2 diabetes, where chronic high blood sugar can harm these cells. The research focused on whether long-term exposure to ketohexoses—such as d-allulose, d-fructose, d-tagatose, l-allulose, l-sorbose, and l-fructose—causes damage, suppresses insulin gene expression, or induces apoptosis in INS-1 rat pancreatic insulinoma cells. The findings showed that d-fructose, d-tagatose, l-allulose, and l-sorbose reduced insulin gene expression, while d-allulose, d-sorbose, l-fructose, and l-tagatose did not. None of the sugars caused cell apoptosis or altered glucose metabolism, indicating that long-term use of d-allulose, d-sorbose, l-fructose, and l-tagatose is unlikely to negatively impact pancreatic β-cell function.
A head-to-head comparison review of biological and toxicological studies of isomaltulose, d-tagatose, and trehalose on glycemic control
This study explores the benefits of three natural, low-glycemic sugars—isomaltulose, D-tagatose, and trehalose—in managing diabetes. These sugars, which are not produced by the human body but are commonly used in food products, help regulate blood sugar levels and improve insulin response, aiding in better control of hyperglycemia in diabetic patients. The review compares these sugars with other sweeteners and emphasizes their potential in both pharmaceutical and food industries for improving the health of people with diabetes.
Mammalian metabolism of erythritol: a predictive biomarker of metabolic dysfunction
This study investigated the impact of diet and genetic factors on erythritol levels in mice, a biomarker linked to diabetes and cardiovascular issues. Researchers fed mice different diets (low-fat or high-fat) and provided them with either plain water or sucrose water. They measured erythritol concentrations in blood, urine, and tissues. The study found that dietary sucrose significantly increased erythritol levels, regardless of the mice’s diet. The presence or absence of certain enzymes (SORD and ADH1) did not significantly influence plasma erythritol levels, but mice lacking the SORD enzyme had lower kidney erythritol content when fed sucrose.
D-Tagatose Is a Promising Sweetener to Control Glycaemia: A New Functional Food
Studies have shown that tagatose has low glycemic index, a potent hypoglycemic effect, and eventually could be associated with important benefits for the treatment of obesity. The authors concluded that D-tag is promising as a sweetener without major adverse effects observed in these clinical studies.”
Tagatose: from a sweetener to a new diabetic medication?
This study tested the dietary effect of the consumption of tagatose in type 2 diabetes and its ability to be a functional food for diabetics.
Effect of Oral Nutritional Supplements with Sucromalt and Isomaltulose versus Standard Formula on Glycaemic Index, Entero-Insular Axis Peptides and Subjective Appetite in Patients with Type 2 Diabetes: A Randomised Cross-Over Study
This study looked at how special oral nutritional supplements for people with type 2 diabetes (ONS-D) affect their blood sugar levels, insulin levels, hormones related to digestion (GIP and GLP-1), and subjective appetite. The ONS-D supplements had a lower impact on blood sugar levels compared to a standard formula, and they also resulted in lower insulin and GIP levels. However, the ONS-D supplements increased the levels of GLP-1, which is beneficial for diabetes management. People who consumed the ONS-D felt less hungry compared to those who had the standard formula. These findings suggest that the ONS-D supplements can help control blood sugar levels and appetite in individuals with type 2 diabetes.
Short-term replacement of starch with isomaltulose enhances both insulin-dependent and -independent glucose uptake in rat skeletal muscle
This study investigated the impact of replacing high-glycemic index carbohydrates with a low-glycemic index disaccharide called isomaltulose on insulin action in skeletal muscle. Male rats were fed isomaltulose for 12 hours, and the results showed that isomaltulose increased insulin-induced glucose uptake in muscle tissue compared to starch. This effect was not influenced by changes in visceral fat mass. Additionally, isomaltulose treatment enhanced glucose uptake in response to exercise and increased AMP-activated protein kinase phosphorylation. These findings suggest that temporarily replacing starch with isomaltulose, along with exercise, may be a promising approach for managing insulin resistance.
Low Glycemic Index Prototype Isomaltulose-Update of Clinical Trials
Low glycemic index diets are considered beneficial for blood glucose control in diabetes and overall metabolic health. Isomaltulose, a natural disaccharide derived from sucrose, is a prototype of low-glycemic index carbohydrates. It is widely used in various food applications and clinical nutrition feeds. This overview examines clinical trials on isomaltulose, including its impact on glycemia, fat oxidation, weight-loss maintenance, and pregnancy. The findings suggest potential advantages of isomaltulose compared to high glycemic index sugars and carbohydrates in these contexts.
Prevalence of auto-antibodies against D-ribose-glycated-hemoglobin in diabetes mellitus
High blood sugar levels lead to the formation of advanced glycation end products (AGEs), which contribute to the progression of diabetes. In a study, structural changes in hemoglobin (Hb) caused by D-ribose were observed, potentially triggering an autoimmune response in diabetic patients. Autoantibodies against D-ribose glycated-Hb were found to be prevalent in diabetic patients’ blood, indicating their potential as biomarkers for diabetes progression.
Ramadan and Diabetes: A Narrative Review and Practice Update
This review explores the impact of fasting during the Islamic month of Ramadan on patients with diabetes mellitus. It provides recommendations for managing diabetes during Ramadan, emphasizing the importance of pre-Ramadan assessments to ensure a safe fasting experience. The review acknowledges the personal choice to fast but advises against fasting for patients assessed to be at high or very high risk, especially considering the additional risk posed by the COVID-19 pandemic. Advanced insulin delivery and glucose monitoring technologies are highlighted as helpful tools for supporting high-risk patients. While formal trial data is limited, there is sufficient evidence on the safety and efficacy of various hypoglycemic agents to guide treatment decisions. Overall, Ramadan presents an opportunity for patient engagement and improved diabetes management.
Flavonoids and Their Anti-Diabetic Effects: Cellular Mechanisms and Effects to Improve Blood Sugar Levels
Diabetes mellitus is a prevalent metabolic disorder, and flavonoids, natural compounds found in fruits and vegetables, have shown potential in managing diabetes. This review summarizes the current understanding of how dietary flavonoids affect glucose metabolism, hepatic enzymes, and lipid profiles, offering insights into their anti-diabetic effects. Further research is needed to clarify the mechanisms of action and potential side effects of flavonoids for diabetes treatment.
Association between HbA1c and carotid atherosclerosis among elderly Koreans with normal fasting glucose
This study investigated the association between glycated hemoglobin (HbA1c) and carotid atherosclerosis in an elderly Korean population with normal fasting glucose. The analysis of 1,133 participants revealed that higher HbA1c levels were independently associated with increased carotid intima-media thickness (IMT), indicating carotid atherosclerosis. This association remained significant after adjusting for various factors. However, fasting insulin and glucose levels did not show a significant association with carotid IMT. These findings suggest that HbA1c may serve as an informative marker for carotid atherosclerosis in elderly individuals with normoglycemia.
Effects of Three Low-Doses of D-Tagatose on Glycemic Control Over Six Months in Subjects with Mild Type 2 Diabetes Mellitus Under Control with Diet and Exercise
This study examined the safety and effectiveness of D-tagatose in individuals with type 2 diabetes. Participants received different doses of D-tagatose for six months. The 7.5 g dose showed the greatest success in reducing HbA1c levels, while the 5.0 g dose was the minimum effective dose. D-tagatose was well tolerated, and higher doses resulted in greater improvements in various measures.
Safety and Efficacy of D-Tagatose in Glycemic Control in Subjects with Type 2 Diabetes
This study aimed to assess the effects of D-tagatose on glycemic control and safety in individuals with type 2 diabetes. Participants received either D-tagatose or a placebo. D-tagatose significantly reduced HbA1c levels compared to placebo and also showed positive effects on fasting blood glucose, LDL cholesterol, total cholesterol, and the proportion of subjects achieving HbA1c targets. However, D-tagatose did not affect triglyceride levels or HDL cholesterol. Overall, D-tagatose was effective in treating various therapy targets of type 2 diabetes.
Dietary supplementation with d-tagatose in subjects with type 2 diabetes leads to weight loss and raises high-density lipoprotein cholesterol
This pilot study investigated the effects of oral d-tagatose on individuals with type 2 diabetes. Participants took 15 g of d-tagatose three times daily for 1 year. No serious adverse effects were observed, although some experienced mild and transient gastrointestinal side effects. After excluding subjects who had changes in diabetes medications, body weight decreased significantly, and there was a non-significant reduction in glycated hemoglobin levels. Among participants not on lipid-modifying medications, high-density lipoprotein cholesterol levels increased significantly. These findings suggest that d-tagatose may have potential as an adjunct in the management of type 2 diabetes.
Daily consumption of one teaspoon of trehalose can help maintain glucose homeostasis: a double-blind, randomized controlled trial conducted in healthy volunteers
Researchers conducted a study to see if consuming 3.3 g of trehalose daily improves glucose tolerance in healthy Japanese individuals. They compared it to a group consuming sucrose. After 12 weeks, the trehalose group had lower fasting and post-meal blood glucose levels compared to the sucrose group. This suggests that even a small amount of trehalose could help lower post-meal blood sugar in healthy individuals.
Childhood neurodevelopmental disorders and maternal diabetes: A population-based cohort study
A retrospective cohort study in Taiwan examined the risk of neurodevelopmental disorders (NDDs) in children born to mothers with different types of diabetes. The study found that offspring of mothers with type 1 diabetes had the highest risk of NDDs, followed by type 2 diabetes and gestational diabetes. Specific disorders such as autism spectrum disorder, attention-deficit/hyperactivity disorder, developmental delay, intellectual disability, cerebral palsy, and epilepsy/infantile spasms were associated with maternal diabetes. This study highlights the importance of understanding the potential risks of different types of diabetes on neurodevelopment in offspring.
Prediabetes and risk of mortality, diabetes-related complications and comorbidities: umbrella review of meta-analyses of prospective studies
This umbrella review analyzed the available evidence from meta-analyses of prospective observational studies to evaluate the associations between prediabetes and the incidence of diabetes-related complications in adults. The review found that prediabetes was associated with an increased risk of all-cause mortality, cardiovascular outcomes, coronary heart disease, stroke, chronic kidney disease, certain cancers, and dementia. However, no associations were observed with incident depressive symptoms and cognitive impairment. The certainty of evidence varied across the outcomes. The review highlights the need for further high-quality studies, especially focusing on HbA1c-defined prediabetes and other relevant health outcomes, to strengthen the evidence in this area.
Ketogenic diet – a literature review
The ketogenic diet has gained attention for its potential benefits in various health conditions. It has been found to aid in weight reduction, improve lipid profile, and potentially reduce the need for antidiabetic drugs and insulin therapy in type 2 diabetes. Animal studies suggest positive effects in cancer treatment, although human studies are limited. Additionally, there are reports of the ketogenic diet delaying the onset of dementia symptoms. However, the long-term impact on cardiovascular risk is still unknown, emphasizing the need for careful consideration before adopting the diet.
Significant Systemic Insulin Resistance is Associated With Unique Glioblastoma Multiforme Phenotype
This study investigated the relationship between insulin resistance and a specific type of brain cancer called glioblastoma multiforme (GBM), which is characterized by the presence of gemistocytes (GCs). These GCs are typically associated with reactive astrocytes, a type of brain cell. The study aimed to find a connection between insulin resistance and the presence of GCs in newly diagnosed GBM patients.
The researchers looked at medical records of 220 patients with newly diagnosed GBM. Among these patients, 26.3% had a history of type 2 diabetes at the time of diagnosis. They found that in the group of GBM patients with GCs, poorly-controlled diabetes was more common compared to the group without GCs. Specifically, there was a higher prevalence of poorly-controlled diabetes in the GC-GBM group (18.75%) compared to the non-GC GBM group (9.5%). In the subset of diabetic patients, those with GC-GBM were more likely to exhibit characteristics of insulin resistance, such as being male, morbidly obese, and not using synthetic insulin before diagnosis.
In conclusion, this study suggests that systemic metabolic factors related to insulin resistance, including type 2 diabetes, morbid obesity, and male gender, are associated with a distinct histological subtype of GBM characterized by the presence of GCs. This association is particularly significant in poorly-controlled type 2 diabetes GBM patients who do not use synthetic insulin. The findings highlight the potential relevance of glucose metabolism in astrocytes and its connection to high-grade brain tumors. Further research is needed to explore how patients’ metabolic status, tumor characteristics, molecular changes, and use of anti-diabetic drugs impact survival in GBM patients.
Hyperinsulinemia acts via acinar insulin receptors to initiate pancreatic cancer by increasing digestive enzyme production and inflammation
This study explores the link between pancreatic cancer, obesity, type 2 diabetes, and high levels of insulin in the blood (hyperinsulinemia). It is known that high insulin production is an independent risk factor for cancer, including pancreatic cancer. Previous research showed that reducing insulin production could suppress the development of pre-cancerous pancreatic lesions (PanIN) in mice with a specific genetic mutation (Kras). However, the precise mechanisms behind this connection and whether hyperinsulinemia directly affects PanIN precursor cells were unclear.
The study found that insulin receptors (Insr) in pancreatic acinar cells expressing the KrasG12D mutation were not essential for regulating glucose levels but were crucial for the formation of PanIN lesions in the presence of diet-induced hyperinsulinemia and obesity. The mechanism behind this involved an increase in the translation of digestive enzyme proteins, which led to local inflammation and the development of PanIN lesions in vivo. In laboratory experiments, insulin was shown to promote the transformation of acinar cells into ductal cells (acinar-to-ductal metaplasia) in a manner dependent on trypsin and insulin receptors.
In summary, this study sheds light on how obesity-driven hyperinsulinemia is connected to the development of pancreatic cancer. It shows that insulin receptors in pancreatic cells are not required for regulating blood sugar but play a crucial role in the formation of pre-cancerous pancreatic lesions under conditions of obesity and high insulin levels. The study provides insights into the mechanisms underlying the link between hyperinsulinemia and the development of pancreatic cancer.
Trehalose alleviates oxidative stress-mediated liver injury and Mallor-Denk body formation via activating autophagy in mice
Trehalose, a disaccharide, has been shown to induce autophagy and reduce cellular stress in various disease models. However, its effects in hepatocytes have not been fully investigated. In a study using mice treated with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC), trehalose was found to induce autophagy, reduce endoplasmic reticulum stress, oxidative stress, Mallory-Denk body formation, and apoptosis in hepatocytes. Electron microscopy revealed the formation of autolysosomes in close proximity to the Mallory-Denk bodies. These findings suggest that trehalose has the potential to be a therapeutic agent for liver diseases associated with oxidative stress by activating autophagy.
Trehalose improves traumatic brain injury-induced cognitive impairment
This study investigated the potential of trehalose, a natural sugar, to treat Alzheimer’s disease (AD) in a mouse model. The study found that trehalose improved the cognitive performance of mice through mechanisms that were independent of the reduction of Aβ protein or activation of autophagy. Trehalose increased the levels of proteins associated with synapses and neurogenesis, suggesting a neuroprotective effect. The study suggests that trehalose may be a potential treatment option for AD and other neurodegenerative disorders.
Trehalose Improves Cognition in the Transgenic Tg2576 Mouse Model of Alzheimer’s Disease
This study investigated the therapeutic effects of trehalose in a mouse model of Alzheimer’s disease (AD). Trehalose treatment improved cognitive performance without significant changes in amyloid-β protein levels or autophagy. There was also no significant alteration in metal levels. However, trehalose treatment led to increased levels of synaptophysin, doublecortin, and progranulin, indicating enhanced synaptic function and neurogenesis. These findings suggest that trehalose may have neuroprotective mechanisms independent of traditional pathways, making it a potential therapeutic option for AD and other neurodegenerative disorders.
Human TKTL1 implies greater neurogenesis in frontal neocortex of modern humans than Neanderthals
This study investigated the role of the TKTL1 gene in neocortex development and its impact on neuroprogenitor numbers. The researchers found that the human-specific amino acid substitution in TKTL1 (hTKTL1) increased the abundance of basal radial glia (bRG), a type of neuroprogenitor associated with increased cortical neuron production. The Neanderthal variant of TKTL1 (aTKTL1) did not have the same effect. Additionally, hTKTL1 promoted the synthesis of specific membrane lipids required for bRG growth. The findings suggest that hTKTL1 contributes to greater neocortical neurogenesis in modern humans, particularly in the frontal lobe, compared to Neanderthals.
Scaling brain neurogenesis across evolution
The neocortex, responsible for cognitive abilities, has expanded and folded in mammals, partly due to basal radial glial cells (bRGs). A study by Pinson et al. reveals that a variant of transketolase-like protein 1 (TKTL1) in modern humans increases the number of bRGs and upper layer projection neurons. This genetic change may contribute to cognitive differences between modern humans and extinct archaic humans.
Trehalose alleviates oxidative stress-mediated liver injury and Mallor-Denk body formation via activating autophagy in mice
This study investigated the effects of trehalose on autophagy, ER stress, oxidative stress-mediated cytotoxicity, and Mallory-Denk body (MDB) formation in hepatocytes. The study used a mice model with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) treatment and administered trehalose through intraperitoneal injection. The results showed that trehalose induced autophagy, reduced ER stress, oxidative stress, MDB formation, and apoptosis in hepatocytes. Electron microscopy revealed autolysosome formation close to the MDBs. These findings suggest that trehalose has the potential to be a therapeutic agent for oxidative stress-related liver diseases by activating autophagy.
Trehalose improves traumatic brain injury-induced cognitive impairment
In this study, researchers investigated the therapeutic potential of trehalose in a mouse model of traumatic brain injury (TBI). Trehalose, known for its neuroprotective properties, was found to improve behavioral performance in TBI mice without affecting lesion volume or biometals. However, trehalose treatment resulted in an upregulation of synaptic proteins and neurotrophic factors in the contralateral cortex. These findings suggest that trehalose could be an effective treatment option for TBI and other central nervous system disorders
Trehalose Improves Cognition in the Transgenic Tg2576 Mouse Model of Alzheimer’s Disease
This study investigated the therapeutic effects of trehalose in a mouse model of Alzheimer’s disease (AD). Trehalose treatment improved cognitive performance without significant changes in amyloid-β protein levels or autophagy. There was also no significant alteration in metal levels. However, trehalose treatment led to increased levels of synaptophysin, doublecortin, and progranulin, indicating enhanced synaptic function and neurogenesis. These findings suggest that trehalose may have neuroprotective mechanisms independent of traditional pathways, making it a potential therapeutic option for AD and other neurodegenerative disorders.
Scaling brain neurogenesis across evolution
The neocortex, responsible for cognitive abilities, has evolved and expanded across mammals. Humans’ advanced cognitive abilities are attributed to neocortex size and structure. Basal radial glial cells (bRGs) play a role in neocortex expansion and folding. A study by Pinson et al. found that a variant of transketolase-like protein 1 (TKTL1) in modern humans increases the number of bRGs and upper layer projection neurons. This genetic change may contribute to cognitive differences between modern humans and extinct archaic humans.
Human TKTL1 implies greater neurogenesis in frontal neocortex of modern humans than Neanderthals
This scientific article explores the differences in neurogenesis (the formation of new neurons) between modern humans and Neanderthals. Although Neanderthals had brains similar in size to modern humans, researchers discovered a genetic difference in a specific protein called transketolase-like 1 (TKTL1). The modern human variant of this protein, hTKTL1, was found to increase the abundance of basal radial glia (bRG) during neocortex development. These bRG cells play a crucial role in generating neurons. However, the Neanderthal variant of the protein did not have the same effect on bRG. The study suggests that modern humans have a different process of neurogenesis compared to Neanderthals, which may have contributed to unique characteristics of the human brain.
The influence of D-ribose ingestion and fitness level on performance and recovery.
Skeletal muscle adenosine triphosphate (ATP) levels are severely depleted during and following prolonged high intensity exercise. this study was designed to determine what influence D-ribose might have on muscular performance, recovery, and metabolism during and following a multi-day exercise regimen.
The influence of a 12% carbohydrate-electrolyte beverage on self-paced soccer-specific exercise performance
This study investigated the effects of consuming a 12% carbohydrate-electrolyte beverage during simulated soccer match-play. The beverage improved self-paced exercise performance and dribbling speed compared to water and placebo. Blood glucose levels were higher with the carbohydrate-electrolyte beverage, but it did not attenuate post-exercise cognitive decline. Overall, the findings suggest that the beverage can enhance soccer performance.
Remodelling of Oxidative Energy Metabolism by Galactose Improves Glucose Handling and Metabolic Switching in Human Skeletal Muscle Cells
This study explored how switching the energy source from glucose to galactose in cultured muscle cells (myotubes) affects their metabolism. Cells grown with galactose showed improved ability to burn fatty acids and glucose, as well as increased mitochondrial function and content. They also handled glucose better and were more flexible in switching between using fats and glucose for energy. This suggests that galactose helps boost oxidative metabolism and could be a useful model for studying conditions like insulin resistance and mitochondrial disorders.
D-tagatose protects against oleic acid-induced acute respiratory distress syndrome in rats by activating PTEN/PI3K/AKT pathway
This study investigates the potential benefits of D-tagatose (TAG), a low-calorie sugar, in treating acute respiratory distress syndrome (ARDS), a condition marked by lung inflammation and fluid buildup. Using an oleic acid-induced ARDS rat model, researchers found that TAG significantly protected lung tissues. In the experiment, rats were divided into three groups: a control group, an ARDS group, and a TAG-treated ARDS group. TAG treatment, administered three days before inducing ARDS, improved oxygen levels, reduced respiratory acidosis, and decreased inflammation. Additionally, TAG improved lung vascular permeability and supported the maintenance of lung structure by promoting the differentiation of alveolar cells. These benefits are thought to be mediated through the PTEN/PI3K/AKT pathway, suggesting TAG as a potential new treatment for ARDS.
Ingesting isomaltulose versus fructose-maltodextrin during prolonged moderate-heavy exercise increases fat oxidation but impairs gastrointestinal comfort and cycling performance
This study examined the metabolic and performance effects of ingesting isomaltulose, a slowly absorbed carbohydrate, during exercise. The results showed that isomaltulose increased plasma nonesterified fatty acid concentration and fat oxidation while decreasing carbohydrate oxidation compared to fructose-maltodextrin supplementation. However, isomaltulose ingestion led to severe gastrointestinal symptoms and negatively affected exercise performance. These findings suggest that isomaltulose may not be suitable for prolonged or high-intensity exercise compared to other carbohydrate supplements.
Galactose increases mitochondrial activity which induces fat mobilisation and fat burning
This study focused on the role of transketolase (TKT) in colorectal cancer. The researchers found that TKT expression was significantly increased in colorectal cancer and correlated with poor prognosis. TKT was found to promote cancer cell growth and metastasis by interacting with GRP78 and enhancing glycolysis through AKT phosphorylation. These findings suggest that TKT could serve as a prognostic indicator for colorectal cancer and potentially be targeted for the development of new treatment strategies.
Substrate Utilization and Cycling Performance Following Palatinose™ Ingestion: A Randomized, Double-Blind, Controlled Trial
This study compared the effects of isomaltulose (PSE) and maltodextrin (MDX) ingestion on endurance exercise performance. PSE resulted in improved time trial performance, higher fat oxidation, and a more stable blood glucose profile compared to MDX. PSE may enhance endurance by promoting fat utilization and preserving glycogen.
Exogenous Oxidation of Isomaltulose Is Lower than That of Sucrose during Exercise in Men
This study compared the effects of orally ingested isomaltulose (ISO) and sucrose (SUC) during moderate intensity exercise. ISO showed lower exogenous carbohydrate oxidation rates and higher fat oxidation compared to SUC. Total endogenous carbohydrate oxidation was lower in the SUC trial. ISO had a lower plasma insulin response and a slower rate of digestion compared to SUC. These findings suggest that ISO may promote higher fat utilization and lower reliance on exogenous carbohydrates during exercise.
Low vs. high glycemic index carbohydrate gel ingestion during simulated 64-km cycling time trial performance
This study investigated the effects of low and high glycemic index (GI) carbohydrate feedings during a simulated 64-km cycling time trial (TT). The results showed no significant differences in the overall time to complete the TT between the low GI (honey) and high GI (dextrose) carbohydrate conditions. However, when collapsed, the carbohydrate conditions were faster compared to the placebo condition. Analysis of wattage generated during the last 16 km of the TT showed significant improvements in both the dextrose and honey treatments compared to preceding segments. These findings suggest that carbohydrate supplementation, regardless of GI, may enhance performance during the later stages of a long-distance cycling time trial.
Glycemic index in sport nutrition
The glycemic index (GI) classification of carbohydrates has gained attention in sports nutrition for its potential to impact blood glucose and insulin responses, glycogen recovery, exercise metabolism, and lipid oxidation. While there is biochemical evidence supporting the effects of GI manipulation on adipocyte lipolysis and lipid and carbohydrate oxidation rates during exercise, the functional outcomes have been inconsistent. Some studies have shown improved exercise performance with GI manipulation, but many others have not. This article reviews the effects and limitations of GI manipulation in sports nutrition and proposes a comprehensive strategy for its application.
American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance
The Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine state that nutrition plays a crucial role in enhancing sports performance and recovery. These organizations provide guidelines on the appropriate type, amount, and timing of food, fluids, and supplements for optimal health and performance in various training and competitive sport scenarios. This position paper serves as a reference for members of these organizations, professional associations, government agencies, industry, and the public. It emphasizes the importance of personalized nutrition plans developed by registered dietitian/nutritionists, particularly those who are Certified Specialists in Sports Dietetics (CSSD), who are experts in sports nutrition.
Novel findings on the metabolic effects of the low glycaemic carbohydrate isomaltulose (Palatinose)
This study included three human intervention trials to investigate the physiological characteristics of isomaltulose (iso). The results showed that iso is effectively absorbed from the small intestine, regardless of the food matrix, and provides a prolonged delivery of blood glucose. It was found to have lower postprandial blood glucose and insulin responses compared to sucrose. Regular consumption of iso within a Western-type diet was well tolerated and did not affect blood lipids in individuals with hyperlipidemia. Although no significant differences were observed compared to sucrose after the 4-week intervention, iso shows promise as a carbohydrate option for individuals at risk of vascular diseases.
Single Ingestion of Trehalose Enhances Prolonged Exercise Performance by Effective Use of Glucose and Lipid in Healthy Men
In a study with 12 healthy men, the effect of trehalose on prolonged exercise performance was investigated. Participants ingested 8% trehalose, 8% glucose, or water in three separate trials. The ingestion of trehalose resulted in lower adrenaline levels compared to water and glucose during later stages of exercise, indicating better preservation of carbohydrates. These findings suggest that a single intake of trehalose can contribute to maintaining exercise performance over a longer period.
Influence of Trehalose Mouth Rinse on Anaerobic and Aerobic Exercise Performance
Trehalose, a slow-absorbing disaccharide with a low glycemic index, has gained attention in sports nutrition. Limited studies have explored its impact on exercise performance. While pre-exercise ingestion of trehalose did not improve time trial performance, it showed potential in enhancing aerobic and anaerobic performance within 30 minutes of ingestion. Exogenous carbohydrate, including trehalose, may not directly contribute to performance but could have an effect through mechanisms like the mouth rinse effect. A study with collegiate runners used a randomized crossover design to investigate the performance-enhancing effects of trehalose, maltose, and an artificial sweetener through mouth rinsing. The concentrations of these substances were chosen to produce similar sweetness.
Effects of a Single Ingestion of Trehalose during Prolonged Exercise
This scientific article investigates the effects of trehalose (TRE) on exercise performance and energy metabolism. Trehalose is a disaccharide that slowly raises blood glucose levels and reduces insulin secretion. The study involved two parts:
- Exercise Performance: The researchers conducted exercise tests using the Wingate test and a 30-minute constant load exercise. Healthy male college students participated in three trials: water (placebo), glucose (GLU), and trehalose (TRE). The results showed that TRE ingestion significantly increased both average and maximum power values during exercise compared to the other groups (p < 0.01).
- Energy Metabolism: After ingesting TRE, the study measured respiratory exchange ratio (RER) and estimated lipid oxidation during 60 minutes of exercise at 40% VO2peak. The findings indicated that TRE ingestion resulted in significantly higher lipid utilization compared to GLU, suggesting that TRE is more effective in utilizing both glucose and lipids for energy during exercise (p < 0.01).
In summary, the study provides new insights into the positive effects of a single TRE ingestion on prolonged exercise performance by efficiently utilizing glucose and lipids for energy.
Preexercise galactose and glucose ingestion on fuel use during exercise
This study looked at how consuming two different types of sugar, galactose (Gal) and glucose (Glu), 30 minutes before exercise affects the use of these sugars during exercise. They had trained male cyclists do three cycling sessions after fasting overnight, and they consumed either a placebo, Gal, or Glu drink before each session.
The study found that Glu increased the use of the sugar from the drink during the first hour of exercise, while Gal was more effective during the last hour. Glu also led to higher glucose levels in the blood and the liver during exercise. However, there were no significant differences in overall carbohydrate or fat use between the two sugar types.
In summary, consuming Glu before exercise provides a quick source of energy in the early stages of exercise, while Gal becomes the primary source of fuel in the later stages, reducing the reliance on liver glucose.
Oxidation of independent and combined ingested galactose and glucose during exercise
This study investigated the impact of consuming a mixture of glucose and galactose during exercise on the utilization of ingested galactose. Fourteen trained male and female participants engaged in 150 minutes of cycling exercise at 50% peak power while ingesting different carbohydrate beverages. They consumed either galactose (GAL), glucose (GLU), or a combination of both (GAL + GLU) in a 1:1 ratio. The study used isotope labelling to measure the oxidation of the carbohydrates.
The study found that when participants consumed GAL + GLU, the concentration of galactose in their blood was lower compared to when they consumed GAL alone. However, combining galactose with glucose did not enhance the oxidation of ingested galactose during exercise. The total oxidation of the combined galactose-glucose blend (COMBINE) was similar to that of glucose alone, suggesting that these blends are a valid alternative to glucose as an energy source during exercise.
In summary, combining glucose and galactose did not enhance the use of ingested galactose during exercise. Galactose-glucose blends can serve as a viable carbohydrate source for energy during exercise, offering similar benefits to pure glucose.
Trehalose alleviates oxidative stress-mediated liver injury and Mallor-Denk body formation via activating autophagy in mice
Trehalose, a disaccharide, has been shown to induce autophagy and reduce cellular stress in various disease models. However, its effects in hepatocytes have not been fully investigated. In a study using mice treated with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC), trehalose was found to induce autophagy, reduce endoplasmic reticulum stress, oxidative stress, Mallory-Denk body formation, and apoptosis in hepatocytes. Electron microscopy revealed the formation of autolysosomes in close proximity to the Mallory-Denk bodies. These findings suggest that trehalose has the potential to be a therapeutic agent for liver diseases associated with oxidative stress by activating autophagy.
Trehalose alleviates oxidative stress-mediated liver injury and Mallor-Denk body formation via activating autophagy in mice
This study investigated the effects of trehalose on autophagy, ER stress, oxidative stress-mediated cytotoxicity, and Mallory-Denk body (MDB) formation in hepatocytes. The study used a mice model with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) treatment and administered trehalose through intraperitoneal injection. The results showed that trehalose induced autophagy, reduced ER stress, oxidative stress, MDB formation, and apoptosis in hepatocytes. Electron microscopy revealed autolysosome formation close to the MDBs. These findings suggest that trehalose has the potential to be a therapeutic agent for oxidative stress-related liver diseases by activating autophagy.
A Combination of Nicotinamide and D-Ribose (RiaGev) Is Safe and Effective to Increase NAD+ Metabolome in Healthy Middle-Aged Adults: A Randomized, Triple-Blind, Placebo-Controlled, Cross-Over Pilot Clinical Trial
This study evaluated the effects of RiaGev, a combination of nicotinamide and D-ribose, on NAD+ metabolome enhancement in healthy middle-aged adults. Supplementing 1520 mg twice daily for 7 days significantly increased NAD+ metabolites, reduced blood glucose without altering insulin secretion, and decreased waking cortisol levels. Participants also reported less fatigue and improved mental focus, with no adverse effects observed, demonstrating RiaGev’s safety and efficacy.
Ecological impact of a rare sugar on grapevine phyllosphere microbial communities
Plants host a complex microbiota inside or outside their tissues, and phyllosphere microorganisms can be influenced by environmental, nutritional and agronomic factors. Rare sugars are defined as monosaccharides with limited availability in nature and they are metabolised by only few certain microbial taxa. Among rare sugars, tagatose (TAG) is a low-calories sweetener that stimulates and inhibits beneficial and pathogenic bacteria in the human gut microbiota, respectively. Based on this differential effect on human-associated microorganisms, we investigated the effect of TAG treatments on the grapevine phyllosphere microorganisms to evaluate whether it can engineer the microbiota and modify the ratio between beneficial and pathogenic plant-associated microorganisms. TAG treatments changed the structure of the leaf microbiota and they successfully reduced leaf infections of downy mildew (caused by Plasmopara viticola) and powdery mildew (caused by Erysiphe necator) under field conditions. TAG increased the relative abundance of indigenous beneficial microorganisms, such as some potential biocontrol agents, which could partially contribute to disease control. The taxonomic composition of fungal and bacterial leaf populations differed according to grapevine locations, therefore TAG effects on the microbial structure were influenced by the composition of the originally residing microbiota. TAG is a promising biopesticide that could shift the balance of pathogenic and beneficial plant-associated microorganisms, suggesting selective nutritional/anti-nutritional properties for some specific taxa. More specifically, TAG displayed possible plant prebiotic effects on the phyllosphere microbiota and this mechanism of action could represent a novel strategy that can be further developed for sustainable plant protection.
Effects of D-Tagatose on the Growth of Intestinal Microflora and the Fermentation of Yogurt
To investigate the effect of tagatose on the growth of intestinal bacteria, various species were cultivated individually on m-PYF medium containing tagatose as a carbon source. The tagatose inhibited the growth of intestinal harmful microorganisms such as Staphylococcus aureus subsp. aureus, Listeria monocytogenes, Vibrio parahaemolyticus, Salmonella Typhimurium, and Pseudomonas fluorescens. In the case of beneficial microorganisms found in the intestine, Lactobacillus casei grew effectively on m-PYF medium containing tagatose, while Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc citreum, and Lactobacillus acidophilus did not. To examine the effect of tagatose on fermentation by Lactobacillus casei, yogurt was prepared with tagatose as a carbon source. The resulting acid production stimulated a remarkable growth of lactic acid bacteria in the yogurt. After fermentation for 24 hours, the viable cell count and viscosity of yogurt were above 8.49 log CFU/mL and 1,266 cps, respectively. Moreover, sensory evaluations showed that the yogurt supplemented with tagatose was as acceptable as control yogurt prepared with glucose as a carbon source. The changes in pH, titratable acidity and lactic acid bacteria in yogurt prepared with tagatose did not show any significant changes during storage for 15 days at 4°C.
Structural features of sugars that trigger or support conidial germination in the filamentous fungus Aspergillus niger
The asexual spores (conidia) of Aspergillus niger germinate to produce hyphae under appropriate conditions. Germination is initiated by conidial swelling and mobilization of internal carbon and energy stores, followed by polarization and emergence of a hyphal germ tube. The effects of different pyranose sugars, all analogues of d-glucose, on the germination of A. niger conidia were explored, and we define germination as the transition from a dormant conidium into a germling. Within germination, we distinguish two distinct stages, the initial swelling of the conidium and subsequent polarized growth. The stage of conidial swelling requires a germination trigger, which we define as a compound that is sensed by the conidium and which leads to catabolism of d-trehalose and isotropic growth. Sugars that triggered germination and outgrowth included d-glucose, d-mannose, and d-xylose. Sugars that triggered germination but did not support subsequent outgrowth included d-tagatose, d-lyxose, and 2-deoxy-d-glucose. Nontriggering sugars included d-galactose, l-glucose, and d-arabinose. Certain nontriggering sugars, including d-galactose, supported outgrowth if added in the presence of a complementary triggering sugar. This division of functions indicates that sugars are involved in two separate events in germination, triggering and subsequent outgrowth, and the structural features of sugars that support each, both, or none of these events are discussed. We also present data on the uptake of sugars during the germination process and discuss possible mechanisms of triggering in the absence of apparent sugar uptake during the initial swelling of conidia.
Effect of L-glucose and D-tagatose on bacterial growth in media and a cooked cured ham product
Cured meats such as ham can undergo premature spoilage on account of the proliferation of lactic acid bacteria. This spoilage is generally evident from a milkiness in the purge of vacuum-packaged sliced ham. Although cured, most hams are at more risk of spoilage than other types of processed meat products because they contain considerably higher concentrations of carbohydrates, approximately 2 to 7%, usually in the form of dextrose and corn syrup solids. Unfortunately, the meat industry is restricted with respect to the choice of preservatives and bactericidal agents. An alternative approach from these chemical compounds would be to use novel carbohydrate sources that are unrecognizable to spoilage bacteria. L-Glucose and D-tagatose are two such potential sugars, and in a series of tests in vitro, the ability of bacteria to utilize each as an energy source was compared to that of D-glucose. Results showed that both L-glucose and D-tagatose are not easily catabolized by a variety of lactic bacteria and not at all by pathogenic bacteria such as Escherichia coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus, and Yersinia enterocolitica. In a separate study, D-glucose, L-glucose, and D-tagatose were added to a chopped and formed ham formulation and the rate of bacterial growth was monitored. Analysis of data by a general linear model revealed that the growth rates of total aerobic and lactic acid bacteria were significantly (P < 0.05) slower for the formulation containing D-tagatose than those containing L- or D-glucose. Levels of Enterobacteriaceae were initially low and these bacteria did not significantly (P < 0.20) change in the presence of any of the sugars used in the meat formulations. Compared to the control sample containing D-glucose, the shelf life of the chopped and formed ham containing D-tagatose at 10 degrees C was extended by 7 to 10 days. These results indicate that D-tagatose could deter the growth of microorganisms and inhibit the rate of spoilage in a meat product containing carbohydrates.
Naturally occurring rare sugars are free radical scavengers and can ameliorate endoplasmic reticulum stress
Because of potential use of naturally occurring rare sugars as sweeteners, their effect on superoxide (SO), hydroxyl and peroxyl radicals and endoplasmic reticulum (ER) stress was examined in human coronary artery endothelial cells. SO generation was measured using the superoxide-reactive probe 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo[1,2-A]pyrazin-3-one hydrochloride chemiluminescence. Phycoerythrin fluorescence based assay was used to monitor scavenging activity of sugars in the presence of hydroxyl or peroxyl radical generators [CuSO4 and azobis (2 amidinopropane) hydrochloride respectively]. Measurements were made in relative light units (RLU). ER stress was measured with an ER stress-sensitive secreted alkaline phosphatase (SAP) assay and by Western blot analysis of the expression and phosphorylation of key proteins in the unfolded protein response, namely CHOP47, eIF2α and JNK1. D-Glucose (27.5 mM) increased SO generation (5536 ± 283 vs. 2963 ± 205 RLU in controls; p < 0.0007) and decreased SAP secretion (73411 ± 3971 vs. 101749 ± 7652 RLU in controls; p < 0.005) indicating ER stress. Treatment of cells with 5.5 or 27.5 mM of D-allulose, D-allose, D-sorbose and D-tagatose reduced SO generation (all p < 0.05). This could not be attributed to inhibition of cellular uptake of dextrose by the rare sugars tested. In a cell free system, all four rare sugars had significantly more SO, hydroxyl and peroxyl radical scavenging activity compared to dextrose (all p < 0.01). Treatment of cells with rare sugars reduced ER stress. However, unlike other three rare sugars, D-sorbose did not inhibit tunicamycin-induced eIF2α phosphorylation. Naturally occurring rare sugars are free radical scavengers and can reduce ER stress.
Cytoprotection by fructose and other ketohexoses during bile salt-induced apoptosis of hepatocytes
Toxic bile salts cause hepatocyte necrosis at high concentrations and apoptosis at lower concentrations. Although fructose prevents bile salt-induced necrosis, the effect of fructose on bile salt-induced apoptosis is unclear. Our aim was to determine if fructose also protects against bile salt-induced apoptosis. Fructose inhibited glycochenodeoxycholate (GCDC)-induced apoptosis in a concentration-dependent manner with a maximum inhibition of 72% +/- 10% at 10 mmol/L. First, we determined if fructose inhibited apoptosis by decreasing adenosine triphosphate (ATP) and intracellular pH (pHi). Although fructose decreased ATP to <25% of basal values, oligomycin (an ATP synthase inhibitor) did not inhibit apoptosis despite decreasing ATP to similar values. Fructose (10 mmol/L) decreased intracellular pH (pHi) by 0.2 U. However, extracellular acidification (pH 6.8), which decreased hepatocyte pHi 0.35 U and is known to inhibit necrosis, actually potentiated apoptosis 1.6-fold. Fructose cytoprotection also could not be explained by induction of bcl-2 transcription or metal chelation. Because we could not attribute fructose cytoprotection to metabolic effects, alterations in the expression of bcl-2, or metal chelation, we next determined if the poorly metabolized ketohexoses, tagatose and sorbose, also inhibited apoptosis; unexpectedly, both ketohexoses inhibited apoptosis. Because bile salt-induced apoptosis and necrosis are inhibited by fructose, these data suggest that similar processes initiate bile salt-induced hepatocyte necrosis and apoptosis. In contrast, acidosis, which inhibits necrosis, potentiates apoptosis. Thus, ketohexose-sensitive pathways appear to initiate both bile salt-induced cell apoptosis and necrosis, whereas dissimilar, pH-sensitive, effector mechanisms execute these two different cell death processes.
Fructose and tagatose protect against oxidative cell injury by iron chelation
To further investigate the mechanism by which fructose affords protection against oxidative cell injury, cultured rat hepatocytes were exposed to cocaine (300 microM) or nitrofurantoin (400 microM). Both drugs elicited massively increased lactate dehydrogenase release. The addition of the ketohexoses D-fructose (metabolized via glycolysis) or D-tagatose (poor glycolytic substrate) significantly attenuated cocaine- and nitrofurantoin-induced cell injury, although both fructose and tagatose caused a rapid depletion of ATP and compromised the cellular energy charge. Furthermore, fructose, tagatose, and sorbose all inhibited in a concentration-dependent manner (0-16 mM) luminolenhanced chemiluminescence (CL) in cell homogenates, indicating that these compounds inhibit the iron-dependent reactive oxygen species (ROS)-mediated peroxidation of luminol. Indeed, both Fe2+ and Fe3+ further increased cocaine-stimulated CL, which was markedly quenched following addition of the ketohexoses. The iron-independent formation of superoxide anion radicals (acetylated cytochrome c reduction) induced by the prooxidant drugs remained unaffected by fructose or tagatose. The iron-chelator deferoxamine similarly protected against prooxidant-induced cell injury. In contrast, the nonchelating aldohexoses D-glucose and D-galactose did not inhibit luminol CL nor did they protect against oxidative cell injury. These data indicate that ketohexoses can effectively protect against prooxidant-induced cell injury, independent of their glycolytic metabolism, by suppressing the iron-catalyzed formation of ROS.
Antioxidant and cytoprotective properties of D-tagatose in cultured murine hepatocytes
D-Tagatose is a zero-energy producing ketohexose that is a powerful cytoprotective agent against chemically induced cell injury. To further explore the underlying mechanisms of cytoprotection, we investigated the effects of D-tagatose on both the generation of superoxide anion radicals and the consequences of oxidative stress driven by prooxidant compounds in intact cells. Primary cultures of hepatocytes derived from male C57BL/6 mice were exposed to the redox cycling drug nitrofurantoin (NFT). Lethal cell injury induced by 300 microM NFT was completely prevented by high concentrations (20 mM) of D-tagatose, whereas equimolar concentrations of glucose, mannitol, or xylose were ineffective. The extent of NFT-induced intracellular superoxide anion radical formation was not altered by D-tagatose, indicating that the ketohexose did not inhibit the reductive bioactivation of NFT. However, the NFT-induced decline of the intracellular GSH content was largely prevented by D-tagatose. The sugar also afforded complete protection against NFT toxicity in hepatocytes that had been chemically depleted of GSH. Furthermore, the ketohexose fully protected from increases in both membrane lipid peroxidation and protein carbonyl formation. In addition, D-tagatose completely prevented oxidative cell injury inflicted by toxic iron overload with ferric nitrilotriacetate (100 microM). In contrast, D-tagatose did not protect against lethal cell injury induced by tert-butyl hydroperoxide, a prooxidant which acts by hydroxyl radical-independent mechanisms and which is partitioned in the lipid bilayer. These results indicate that D-tagatose, which is a weak iron chelator, can antagonize the iron-dependent toxic consequences of intracellular oxidative stress in hepatocytes. The antioxidant properties of D-tagatose may result from sequestering the redox-active iron, thereby protecting more critical targets from the damaging potential of hydroxyl radical.
The impact of sugar consumption on stress driven, emotional and addictive behaviors
High rates of overweight and obesity are a global concern, with overconsumption of high fat/sugar foods playing a significant role. Long-term sugar consumption can lead to neural plasticity, reducing impulse control and increasing susceptibility to high fat/sugar foods. The neural pathways involved in emotions and survival responses overlap, suggesting a link between stress, emotions, and obesity. Sucrose consumption activates the mesocorticolimbic system similarly to addictive substances, resulting in neuronal changes, altered emotional processing, and modified behavior in both animals and humans. This comprehensive review examines over 300 studies on the interaction between sugar consumption, stress, and emotions, emphasizing the neurochemical changes and neural adaptations that influence emotion and behavior after sugar consumption. Understanding these mechanisms can aid in the development of novel therapeutic strategies for obesity.
D-Tagatose Feeding Reduces the Risk of Sugar-Induced Exacerbation of Myocardial I/R Injury When Compared to Its Isomer Fructose
In a study comparing the effects of fructose and D-tagatose on heart health, rats fed a diet high in fructose experienced weight gain, negative changes in glucose, insulin, and lipid levels, and increased heart damage from ischemia/reperfusion injury. In contrast, rats consuming a diet high in D-tagatose, a low-calorie fructose isomer, showed less oxidative stress, lower inflammation, and improved heart protection. D-tagatose also reduced inflammation markers and improved heart enzyme levels compared to fructose. This suggests that D-tagatose may be a healthier alternative to fructose, with less impact on metabolic health and heart disease vulnerability.
Daily limited access to sweetened drink attenuates hypothalamic-pituitary-adrenocortical axis stress responses
A rat model was developed to explore the relationship between preferred food consumption and stress responses. Rats were given access to sweetened drinks (sucrose or saccharin) or water in addition to their regular water intake. Half of the rats were subjected to chronic variable stress (CVS) while the others served as nonhandled controls. The results showed that sucrose consumption reduced the stress hormone corticosterone response to restraint stress in both CVS rats and nonhandled controls. Saccharin had a similar but less pronounced effect. Sucrose consumption also affected gene expression in brain regions associated with stress regulation. These findings suggest that limited consumption of sweetened drinks can attenuate stress responses, indicating that the intake of palatable substances may serve as a natural mechanism to dampen physiological stress responses.
Expression and nuclear translocation of glucocorticoid receptors in type 2 taste receptor cells
The secretion of glucocorticoids (GCs) in response to stress affects ingestive behavior and taste preferences. This study investigated the presence of glucocorticoid receptors (GRs) in taste tissue and their potential role in modulating the response of the taste system to stress. The researchers found mRNA expression of GRα in taste papillae and non-taste tissue, with higher levels in taste tissue. GR protein was detected in various taste bud populations. In transgenic mice, the majority of sweet-/umami-sensitive taste cells expressed GR. When mice were subjected to restraint stress, GR protein in sweet-sensitive taste cells relocated to the nucleus. These findings suggest that GR activation in taste receptor cells may influence taste qualities such as sweet, umami, and bitter, potentially shaping the response of the taste system to stress.
Cross-lagged associations between children’s stress and adiposity: the Children’s Body Composition and Stress study
This longitudinal study found that adiposity (body fat) in children is associated with increased stress levels over time. However, stress does not directly cause increases in adiposity. The relationship between stress and adiposity is influenced by cortisol levels and lifestyle factors. These findings highlight the importance of considering multiple factors in obesity prevention programs and the negative impact of unhealthy body composition on children’s well-being.
Effects of D-Tagatose on the Growth of Intestinal Microflora and the Fermentation of Yogurt
To investigate the effect of tagatose on the growth of intestinal bacteria, various species were cultivated individually on m-PYF medium containing tagatose as a carbon source. The tagatose inhibited the growth of intestinal harmful microorganisms such as Staphylococcus aureus subsp. aureus, Listeria monocytogenes, Vibrio parahaemolyticus, Salmonella Typhimurium, and Pseudomonas fluorescens. In the case of beneficial microorganisms found in the intestine, Lactobacillus casei grew effectively on m-PYF medium containing tagatose, while Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc citreum, and Lactobacillus acidophilus did not. To examine the effect of tagatose on fermentation by Lactobacillus casei, yogurt was prepared with tagatose as a carbon source. The resulting acid production stimulated a remarkable growth of lactic acid bacteria in the yogurt. After fermentation for 24 hours, the viable cell count and viscosity of yogurt were above 8.49 log CFU/mL and 1,266 cps, respectively. Moreover, sensory evaluations showed that the yogurt supplemented with tagatose was as acceptable as control yogurt prepared with glucose as a carbon source. The changes in pH, titratable acidity and lactic acid bacteria in yogurt prepared with tagatose did not show any significant changes during storage for 15 days at 4°C.
90-Day oral toxicity study of D-tagatose in rats
D-tagatose is a ketohexose, tastes like sugar and is useful as a low-calorie sweetener. To assess D-tagatose’s safety, an oral 90-day toxicity study was conducted on male and female Crl:CDBR rats at dietary doses of 5, 10, 15, and 20% D-tagatose. One control group (dietary control) received only lab chow; a second control group received 20% cellulose/fructose in the diet. There were no treatment-related effects at 5% D-tagatose in the diet. At higher doses, treatment-related effects included transient soft stools in male and female animals from the 15 and 20% dose groups. This was anticipated as a result of the osmotic effect of a large dose of relatively undigested sugar and was not considered a toxic effect. All treatment groups gained weight over the study period; however, mean body weights were statistically significantly decreased in the 15 and 20% dose-group males and the 20% dose-group females at selected intervals compared to dietary control animals. No significant reduction in mean food consumption was noted in the treatment groups compared to the dietary control. Statistically significantly increased relative liver weights were noted in male and female animals from the 10, 15, and 20% dose groups compared to the dietary control. No gross pathological findings correlated with these increased liver weights. Minimal hepatocellular hypertrophy was observed in male and female animals from the 15 and 20% dose groups. An independent review of the liver slides concluded that histomorphologic changes associated with D-tagatose were restricted hepatocyte hypertrophy and hepatocyte glycogen accumulation. Therefore, it was concluded that increased liver weights and minimal hypertrophy were the result of adaptation to the high dietary levels (greater than 5% in the diet) of D-tagatose. No adverse effects were seen at 5% D-tagatose in the diet.
The acute effect of D-tagatose on food intake in human subjects
A double-blind randomized crossover study was performed with nineteen normal-weight men to investigate the effect on subsequent ad libitum food intake of replacing 29 g sucrose with 29 g D-tagatose as sweetener to a breakfast meal. D-Tagatose is a malabsorbed stereoisomer of fructose with potential application as a bulk sweetener. Food intake was measured at lunch offered 4 h after the breakfast meal, during the afternoon with access to abundant snacks, and finally at a supper buffet 9 h after the breakfast. Energy intake at lunch and during the snacking period was similar after ingesting the two sugars, while it was 15% lower after ingesting D-tagatose than with sucrose at supper (P < 0.05). Gastrointestinal factors such as the osmotic effects of unabsorbed D-tagatose causing distension of the gut might have mediated the acute appetite-suppressing effect. The present paper also refers to data from a preceding study in which we observed an increased self-reported energy intake after ingestion of D-tagatose compared with sucrose which, in fact, suggests a relative hyperphagic effect of D-tagatose. However, self-reported food intake may be biased by selective under-reporting and this subsequent study with a more controlled assessment of food intake was therefore conducted. This present study did not support any hyperphagic effect of D-tagatose, but rather suggests that D-tagatose may contribute to a reduced energy intake.
DDDAS Design of Drug Interventions for the Treatment of Dyslipidemia in ApoE-/- Mice
Computational models of complex systems, such as signaling networks and biological systems, can be used to explain the behavior of such systems under various conditions. The large number of integrated processes and variables, and the nonlinearities inherent in the fundamental processes, make it difficult for scientists unassisted by computer simulations to effectively predict the consequences of a particular intervention. For this reason, computer simulation has become an important tool for generating hypotheses about the behavior of these systems that can then be tested in the laboratory and clinic. A dynamic data-driven application simulation (DDDAS) was designed by Biospherics to model complex metabolic disease pathways by testing potential binary therapies in simulations at various combinations of two points in the pathways. Since DDDAS chooses the most effective pair-wise combinations, this data-driven system allows for the implementation of real-time data to model or predict a measurement or event. By incorporating data dynamically rather than statically, the predictions and measurements become more reliable. Dyslipidemia, a common precursor to atherosclerosis, can be manifested by high triglycerides, increased apolipoprotein (Apo) B, high levels of LDL, and low levels of HDL. SPX106 and D-tagatose is a combination drug therapy composed of a carbohydrate (D-tagatose) and SPX106. D-tagatose has been studied for the treatment of diabetes for several years, and has the ability to lower blood insulin levels and to decrease glycogen formation. SPX106 is a natural substance that accelerates lipid catabolism and inhibits dyslipidemia. In apolipoprotein E knockout mice (ApoE-/-), this drug combination has been shown to significantly lower both the amount of atherosclerosis and blood cholesterol levels. This study used 26 male ApoE-/- mice (n=13 in each group, control and treated). The control group received the normal “Western” diet (Harlan TD88137) and the treatment group received a modified version in which the sucrose was replaced with D-tagatose and 1g of SPX106 was added for every kilogram of chow. Mice were fed the diet for 8 weeks and then sacrificed via cardiac puncture. Blood serum was analyzed for cholesterol concentration. A significant difference was observed between the control and treated groups for total cholesterol levels. FPLC separations were done on fractions from both control and treated groups. A significant difference between VLDL and HDL levels was found between the treated and control mice (p<0.05 for both). Aortas were also taken and preserved in formalin to be quantified for atherosclerosis. Aortic sinuses were frozen in OCT and sectioned using a cryostat and then quantified for atherosclerosis. Treated mice showed statistically significant reduction in atherosclerosis in the aortic arch (p<0.01), the thoracic aorta (p<0.05), and the aortic sinus (p<0.05) as well as a reduction of cholesterol (p<0.05).
BSN723T Prevents Atherosclerosis and Weight Gain in ApoE Knockout Mice Fed a Western Diet
This study tests the hypothesis that BSN723T can prevent the development of hyperlipidemia and atherosclerosis in ApoE-/- knockout mice fed a Western (high fat, high cholesterol, and high sucrose) diet. BSN723T is a combination drug therapy consisting of D-tagatose and dihydromyricetin (BSN723). D-tagatose has an antihyperglycemic effect in animal and human studies and shows promise as a treatment for type 2 diabetes and obesity. Many claims regarding BSN723’s pharmacological activities have been made including anti-cancer, anti-diabetic, anti-hypertensive, anti-inflammatory, and anti-atherosclerotic effects. To our knowledge this is the first study that combines D-tagatose and BSN723 for the treatment of hyperlipidemia and the prevention of atherosclerosis.ApoE-deficient mice were randomized into five groups with equivalent mean body weights. The mice were given the following diets for 8 weeks: Group 1 – Standard diet; Group 2 – Western diet; Group 3 – Western diet formulated with D-tagatose; Group 4 – Western diet formulated with BSN723; Group 5 – Western diet formulated with BSN723T. Mice were measured for weight gain, tissue and organ weights, total serum cholesterol and triglycerides and formation of atherosclerosis.The addition of D-tagatose, either alone or in combination with BSN723, prevented the increase in adipose tissue and weight gain brought on by the Western diet. Both D-tagatose and BSN723 alone reduced total cholesterol and the formation of atherosclerosis in the aorta compared to mice on the Western diet. Addition of BSN723 to D-tagatose (BSN723T) did not increase efficacy in prevention of increases in cholesterol or atherosclerosis compared to D-tagatose alone. Addition of either D-tagatose or BSN723 alone to a Western diet prevented weight gain, increases in total serum cholesterol and triglycerides, and the formation of atherosclerosis. However, there was no additive or synergistic effect on the measured parameters with the combination BSN723T treatment.
Combined effects of replacement of sucrose with d-tagatose and addition of different probiotic strains on quality characteristics of chocolate milk
Nowadays, tendency to improve human nutrition and consume new healthful foods such as low-calorie and functional ones has been increased. In this study, effects of ratios of sucrose/d-tagatose (100:0, 0:100, or 50:50) as well as type of commercial probiotic strains (Lactobacillus acidophilus LAFTI L10, Lactobacillus casei LAFTI L26, Lactobacillus rhamnosus HN001, and Bifidobacterium animalis subsp. lactis LAFTI B94) on biochemical and microbiological characteristics, percent of residual sugar, color, and sensory attributes of synbiotic chocolate milk were investigated during 21 days of refrigerated storage (5 °C). The treatments inoculated with L. acidophilus, L. casei, L. rhamnosus, and B. lactis showed significantly higher biochemical and color changes compared to non-probiotic ones. The greatest viability at the end of storage was related to the treatment of d-tagatose with L. rhamnosus (T-R) as well as d-tagatose with L. casei (T-C). Although L. acidophilus, L. casei, and L. rhamnosus mostly tended to ferment d-tagatose, B. lactis did not substantially consume the mentioned sugar. In general, the treatments T-R, ST-R (sucrose and d-tagatose with L. rhamnosus), T-B (d-tagatose with B. lactis), and ST-B (sucrose and d-tagatose with B. lactis) were realized as the best ones in terms of probiotic viability, functional property of d-tagatose, and sensory attributes. In conclusion, d-tagatose could be successfully used as a natural sugar substitute with functional properties for probiotic chocolate milks enhancing their health benefits, but the proper selection of ratio of sucrose/d-tagatose and type of probiotic strain is recommended.
Synbiotic impact of tagatose on viability of Lactobacillus rhamnosus strain GG mediated by the phosphotransferase system (PTS)
Synbiotics, the combination of prebiotics and probiotics, has been shown to produce synergistic effects that promote gastrointestinal well-being of host. Tagatose is a low calorie food ingredient with putative health-promoting benefits. Herein, we investigated its synbiotic impact on the viability of Lactobacillus casei 01 and Lactobacillus rhamnosus strain GG and the potential mechanism involved. Tagatose, as a synbiotic substrate, enhanced the growth of L. casei 01 and L. rhamnosus strain GG compared to other prebiotics. Other gut-indigenous such as Clostridium spp. readily utilized fructooligosaccharide (FOS), the most widely used functional prebiotics, but not tagatose. Additionally, tagatose enhanced probiotic functions of L. casei 01 and L. rhamnosus strain GG by reinforcing their attachment on HT-29 intestine epithelial cells and enhancing their cholesterol-lowering activities. Whole transcriptome study and quantitative real-time polymerase chain reaction (qRT-PCR) test showed that the presence of tagatose in L. rhamnosus strain GG caused induction of a large number of genes associated with carbohydrate metabolism including the phosphotransferase system (PTS). Collectively, these results indicate the tagatose enhanced the growth of L. casei 01 and L. rhamnosus strain GG and their probiotic activities by activating tagatose-associated PTS networks. Importantly, this study highlights the potential application of tagatose and L. casei 01 and/or L. rhamnosus strain GG as a synbiotic partner in functional dairy foods (i.e. yogurt and cheese) and therapeutic dietary supplements.
Disposition of D-[U-14C]tagatose in the rat
The purpose of this experiment was to determine the disposition of D-tagatose, under development as a low-calorie sweetener, in conventional and germ-free male rats. One group of conventional rats was fed a diet containing D-tagatose (100 g/kg) mixed with the nonpurified diet (900 g/kg) for 28 days. Then, [U-14C]-labeled D-tagatose was administered as a single dose (approximately 220-380 kBq) to 4 of these adapted rats, as well as to 15 conventional and germ-free rats with no prior exposure (i.e., unadapted) to D-tagatose. Eleven of the 19 dosed animals (4 adapted conventional, 3 unadapted conventional and 2 unadapted germ-free, all dosed orally, plus 2 unadapted conventional dosed intravenously) were placed in metabolism chambers and samples of CO2, urine, and feces taken at regular intervals. At termination, a complete material balance was obtained based on the recovery of 14C. Over the 6-h digestive period, D-tagatose was metabolized to release 39.9 and 13.9% of the oral dose as CO2 in the adapted conventional rats and in the unadapted germ-free rats, respectively. Total releases approximated 68 and 22%, respectively. The difference in CO2 evolution is ascribed to microbial fermentation of D-tagatose in the gut of the conventional rats. The role of adaptation was confirmed by finding 93% less D-tagatose in the feces of the adapted conventional rat than in the feces of the unadapted conventional rat. The intestinal absorption of D-tagatose in the rat is estimated to be 20%. The results demonstrate that D-tagatose is metabolized primarily by microorganisms in the gut of the rat, with an upper limit between 15 and 20% of oral dose metabolized by the host.
Small-bowel absorption of D-tagatose and related effects on carbohydrate digestibility: an ileostomy study
The ketohexose D-tagatose is a new sweetener with a low energy content. This low energy content may be due to either low absorption of the D-tagatose or decreased absorption of other nutrients.The aims of this study were to measure the excretion of D-tagatose from the human small bowel, to calculate the apparent absorption of D-tagatose, and to study the effects of D-tagatose on the small-bowel excretion of other carbohydrates.A controlled diet was served for 2 periods of 2 d during 3 consecutive weeks to 6 ileostomy subjects. In one of the periods, 15 g D-tagatose was added to the diet daily. Duplicate portions of the diet and ileostomy effluents were freeze-dried and analyzed to calculate the apparent net absorption of D-tagatose and carbohydrates.Median D-tagatose excretion was 19% (range: 12-31%), which corresponded to a calculated apparent absorption of 81% (69-88%). Of the total amount of D-tagatose excreted [2.8 g (1.7-4.4 g)], 60% (8-88%) was excreted within 3 h. Between 3 and 5 h, 32% (11-82%) was excreted. Excretion of wet matter increased by 41% (24-52%) with D-tagatose ingestion. Sucrose and D-glucose excretion increased to a small extent, whereas no significant changes were found in the excretion of dry matter, energy, starch, or D-fructose.The apparent absorption of 15 g D-tagatose/d was 81%. D-Tagatose had only a minor influence on the apparent absorption of other nutrients.
D-Tagatose increases butyrate production by the colonic microbiota in healthy men and women
D-Tagatose is partly absorbed in the stomach and small intestine. Most of it is fermented by the large intestinal microbiota. The effect of D-tagatose on the composition of the microbiota and production of short chain fatty acids (SCFAs) was studied in vivo and in vitro. Gastrointestinal (GI) complaints were also studied. The in vivo study was performed according to a randomized, placebo-controlled, double-blind, five-way cross-over design in healthy subjects (12 men and 18 women). All subjects consumed 30 g raspberry jam containing 7.5 or 12.5 g D-tagatose, 7.8 g fructo-oligosaccharides (positive reference), 7.6 g D-tagatose plus 7.5 g fructo-oligosaccharides, or 15.1 g sucrose (negative reference) at breakfast for 2 weeks in different orders. At the end of each treatment period lipids and safety parameters in blood and GI complaints were evaluated by questionnaires, and faecal microbiota and SCFAs were measured. Furthermore, test-tube incubations of faecal slurries with D-tagatose, fructo-oligosaccharides and sucrose were performed. An in vitro model simulating the large intestine was used to assess the mechanistic effect of D-tagatose on microbiota composition and SCFA production. The high-tagatose treatment resulted in increased numbers of faecal lactobacilli in men, but not in women. Also in vitro, lactobacilli increased. Both the test-tube incubations of fresh faeces from the in vivo study with D-tagatose and the study in the in vitro model showed increased butyrate production after all treatments with D-tagatose. High-tagatose, but not low-tagatose, resulted in a slightly increased defecation frequency and stools of thinner consistency. Only a few GI complaints were reported. The data indicate that daily consumption of 7.5 or 12.5 g D-tagatose may lead to increased production of butyrate and to an increase of lactobacilli, without serious GI complaints. In view of the health-promoting effects of butyrate and lactobacilli, D-tagatose may be considered a prebiotic substrate.
The Constipation-Relieving Property of d-Tagatose by Modulating the Composition of Gut Microbiota
D-tagatose, a monosaccharide as well as a dietary supplement, has been reported as having a wide range of applicability in the food industry, however, the prebiotic activity, anticonstipation effects, and related mechanisms are still unclear. In this study, using the loperamide-induced constipation Kunming mice as the animal model, the effects of d-tagatose for the prevention of constipation were evaluated by gastrointestinal transit experiment and defecation experiment. Furthermore, the underlying mechanism was clarified by evaluating the change of the biochemical indicators and analyzing 16S rRNA amplicon of gut microbiota among the different mice groups. The results showed that the gastrointestinal transit rate, fecal number, and weight in six hours were significantly enhanced after the administration of d-tagatose. In addition, d-tagatose significantly increased the serum levels of acetylcholine (Ach) and substance P (SP), whereas the serum levels of nitric oxide (NO) were significantly decreased. Moreover, the 16S rRNA sequencing analysis revealed that the changes in the gut microbiota caused by constipation were restored by d-tagatose treatment. In conclusion, this study indicated that the administration of d-tagatose as a dietary supplement can effectively prevent and relieve constipation in Kunming mice, and it is a promising prebiotic candidate with constipation-relieving properties.
In vitro fermentation pattern of D-tagatose is affected by adaptation of the microbiota from the gastrointestinal tract of pigs
Knowledge of the fermentation pattern of D-tagatose is important for the assessment of energy value and compliance of D-tagatose. In vitro fermentation experiments with pig intestinal contents and bacteria harvested from the gastrointestinal tract of pigs were used to investigate the degradation of D-tagatose and the formation of fermentation products. Two groups of eight pigs were fed either a control diet containing 150 g/kg sucrose or a diet which had 100 g/kg of the sucrose replaced by D-tagatose. After 18 d the pigs were killed and the gastrointestinal contents collected for in vitro studies. No microbial fermentation of D-tagatose occurred in the stomach or in the small intestine, whereas the sugar was fermented in the cecum and colon. Formate, acetate, propionate, butyrate, valerate, caproate and some heptanoate were produced by the microbial fermentation of D-tagatose by gut microbiota. Hydrogen and methane were also produced. The population of D-tagatose-degrading bacteria in fecal samples and the capacity of bacteria from the hindgut to degrade D-tagatose were higher in the pigs adapted to D-tagatose compared with unadapted pigs. In unadapted pigs, the major fermentation product from D-tagatose was acetic acid. Much more butyric and valeric acids were produced from D-tagatose by bacterial slurries of tagatose-adapted pigs compared with unadapted pigs; this was especially the case for samples from the colon. We conclude that D-tagatose is not fermented in the upper gastrointestinal tract, and the ability of the large intestinal microbiota to ferment D-tagatose is dependent on adaptation.
D-tagatose has low small intestinal digestibility but high large intestinal fermentability in pigs
The digestibility of D-tagatose, its effect on the digestibility of macronutrients and the metabolic response of the microbiota of the gastrointestinal tract to the ingestion of this carbohydrate were studied in pigs. Eight pigs were fed a low fiber diet comprising 15% sucrose (control group). Another eight pigs were fed a similar diet except that 100 g sucrose per kg diet was replaced by D-tagatose (test group). After 18 d, the pigs were killed and the gastrointestinal contents removed for analysis. The digestibility of D-tagatose was 25.8 +/- 5.6% in the distal third of the small intestine. The small intestinal digestibilities of dry matter (86.9 +/- 1.3 vs. 92.9 +/- 0.9%), gross energy (74.4 +/- 1.6 vs. 80.7 +/- 1.8%) and sucrose (90.4 +/- 2.5 vs. 98.0 +/- 0.5%) were lower (P < 0. 05) in the pigs fed D-tagatose. Digestibilities of starch, protein and fat did not differ between groups. D-Tagatose, sucrose and starch were fully digested in the large intestine. The fecal digestibilities of energy, dry matter and fat did not differ between the two groups, whereas D-tagatose reduced the fecal digestibility of protein (91.1 +/- 0.6 vs. 93.5 +/- 0.7%, P < 0.05). D-Tagatose served as a substrate for the microbiota in the cecum and proximal colon as indicated by a reduced pH, and a greater ATP concentration, adenylate energy charge (AEC) ratio and concentration of short-chain fatty acids. In particular, the increase in the concentrations of propionate, butyrate and valerate suggests possible health benefits of this monosaccharide.
D-tagatose, a novel low-calorie bulk sweetener with prebiotic properties
Fermentation of D-Tagatose by Human Intestinal Bacteria and Dairy Lactic Acid Bacteria
A number of 174 normal or pathogenic human enteric bacteria and dairy lactic acid bacteria were screened for D-tagatose fermentation by incubation for 48 hours. Selection criteria for fermentation employed included a drop in pH below 5.5 and a distance to controls of more than 0.5. Only a few of the normal occurring enteric human bacteria were able to ferment D-tagatose, among those Enterococcus faecalis, Enterococcus faecium and Lactobacillus strains. D-Tagatose fermentation seems to be common among lactic acid bacteria. Most of the analyzed dairy lactic acid bacteria fermented D-tagatose, and among those Lactobacillus, Leuconostoc and Pediococcus strains fermented most strongly, but also strains of Enterococcus, Streptococcus and Lactococcus fermented D-tagatose. None of the analyzed Bifidobacterium strains fermented tagatose.
Glycogen synthase activation by sugars in isolated hepatocytes
We have investigated the activation by sugars of glycogen synthase in relation to (i) phosphorylase a activity and (ii) changes in the intracellular concentration of glucose 6-phosphate and adenine nucleotides. All the sugars tested in this work present the common denominator of activating glycogen synthase. On the other hand, phosphorylase a activity is decreased by mannose and glucose, unchanged by galactose and xylitol, and increased by tagatose, glyceraldehyde, and fructose. Dihydroxyacetone exerts a biphasic effect on phosphorylase. These findings provide additional evidence proving that glycogen synthase can be activated regardless of the levels of phosphorylase a, clearly establishing that a nonsequential mechanism for the activation of glycogen synthase occurs in liver cells. The glycogen synthase activation state is related to the concentrations of glucose 6-phosphate and adenine nucleotides. In this respect, tagatose, glyceraldehyde, and fructose deplete ATP and increase AMP contents, whereas glucose, mannose, galactose, xylitol, and dihydroxyacetone do not alter the concentration of these nucleotides. In addition, all these sugars, except glyceraldehyde, increase the intracellular content of glucose 6-phosphate. The activation of glycogen synthase by sugars is reflected in decreases on both kinetic constants of the enzyme, M0.5 (for glucose 6-phosphate) and S0.5 (for UDP-glucose). We propose that hepatocyte glycogen synthase is activated by monosaccharides by a mechanism triggered by changes in glucose 6-phosphate and adenine nucleotide concentrations which have been described to modify glycogen synthase phosphatase activity. This mechanism represents a metabolite control of the sugar-induced activation of hepatocyte glycogen synthase.
Effect of diets containing sucrose vs. D-tagatose in hypercholesterolemic mice
Effects of functional sweeteners on the development of the metabolic syndrome and atherosclerosis are unknown. The objective was to compare the effect of dietary carbohydrate in the form of sucrose (SUCR) to D-tagatose (TAG; an isomer of fructose currently used as a low-calorie sweetener) on body weight, blood cholesterol concentrations, hyperglycemia, and atherosclerosis in low-density lipoprotein receptor deficient (LDLr(-/-)) mice. LDLr(-/-) male and female mice were fed either standard murine diet or a diet enriched with TAG or SUCR as carbohydrate sources for 16 weeks. TAG and SUCR diets contained equivalent amounts (g/kg) of protein, fat, and carbohydrate. We measured food intake, body weight, adipocyte diameter, serum cholesterol and lipoprotein concentrations, and aortic atherosclerosis. Macrophage immunostaining and collagen content were examined in aortic root lesions. CONTROL and TAG-fed mice exhibited similar energy intake, body weights and blood glucose and insulin concentrations, but SUCR-fed mice exhibited increased energy intake and became obese and hyperglycemic. Adipocyte diameter increased in female SUCR-fed mice compared to TAG and CONTROL. Male and female SUCR-fed mice had increased serum cholesterol and triglyceride concentrations compared to TAG and CONTROL. Atherosclerosis was increased in SUCR-fed mice of both genders compared to TAG and CONTROL. Lesions from SUCR-fed mice exhibited pronounced macrophage immunostaining and reductions in collagen content compared to TAG and CONTROL mice. These results demonstrate that in comparison to sucrose, equivalent substitution of TAG as dietary carbohydrate does not result in the same extent of obesity, hyperglycemia, hyperlipidemia, and atherosclerosis.
Maximum Permissive Dosage for Transitory Diarrhea, Estimation of Available Energy, and Fate of D-tagatose in Healthy Female Subjects
Healthy adult women were administered D-tagatose (TAG) and the maximum no-effect dose for transient diarrhea was determined. Next, the effects of TAG ingestion on blood glucose and insulin levels, blood TAG concentration and urinary excretion, and exhaled hydrogen gas after TAG ingestion were measured, and the fate of D-tagatose in the body was examined by observing its digestibility and absorption from the small intestine, its fermentation in the large intestine, and its assimilation by intestinal bacteria. The maximum no-effect dose of TAG was 0.25 g/kg body weight, which was similar to that of D-sorbitol. When 5 g and 10 g of TAG were administered, the blood TAG concentration was below the detection limit. Furthermore, the urinary excretion up to 6 hours after ingestion was less than 2% of the amount ingested. Blood glucose and serum insulin concentrations were not changed by TAG ingestion, and exhaled hydrogen gas excretion was not observed with 5 g of TAG, but was clearly increased with 10 g of TAG. However, the amount was smaller than that of the same amount of fructooligosaccharides, and the onset of excretion was delayed. Furthermore, the amount of organic acids produced from TAG in human feces culture experiments was small, suggesting that TAG reaching the large intestine was metabolized to a small amount of short-chain fatty acids by intestinal bacteria. From these results, it was estimated that ingestion of 10 g of TAG did not induce diarrhea, about 5 g was absorbed from the small intestine, and about 2% of the ingested amount was excreted in the urine without being metabolized. The available energy of TAG was estimated based on these results, and the energy conversion coefficient of TAG was classified as 2 kcal/g.
The Ability of Different Ketohexoses to Alter Apo-A-I Structure and Function In Vitro and to Induce Hepatosteatosis, Oxidative Stress, and Impaired Plasma Lipid Profile in Hyperlipidemic Zebrafish
In the current study, we have tested the nonenzymatic glycation activities of ketohexoses, such as tagatose and psicose. Although tagatose-treated apoA-I (t-A-I) and psicose-treated apoA-I (p-A-I) exerted more inhibitory activity you cupric ion-mediated low-density lipoprotein (LDL) oxidation and oxidized LDL (oxLDL) phagocytosis into macrophage than fructose-treated apoA-I (f-A-I). In the lipid-free state, t-A-I and f-A-I showed more multimerized band without crosslinking. Since t-A-I lost its phospholipid binding ability, the rHDL formation was not as successful as f-A-I. However, injecting t-A-I showed more antioxidant activities in zebrafish embryo under the presence of oxLDL. Three weeks of consumption of fructose (50% of wt in Tetrabit/4% cholesterol) showed a 14% elevation of serum triacylglycerol (TG), while tagatose-administered group showed 30% reduction in serum TG compared to high cholesterol control. Fructose-fed group showed the biggest area of Oil Red O staining with the intensity as strong as the HCD control. However, tagatose-consumed group showed much lesser Oil Red O-stained area with the reduction of lipid accumulation. In conclusion, although tagatose treatment caused modification of apoA-I, the functional loss was not as much severe as the fructose treatment in macrophage cell model, zebrafish embryo, and hypercholesterolemic zebrafish model.
Transketolase promotes MAFLD by limiting inosine-induced mitochondrial activity
Metabolic dysfunction-associated fatty liver disease (MAFLD) has a global prevalence of about 25% and no approved therapy. Using metabolomic and proteomic analyses, we identified high expression of hepatic transketolase (TKT), a metabolic enzyme of the pentose phosphate pathway, in human and mouse MAFLD. Hyperinsulinemia promoted TKT expression through the insulin receptor-CCAAT/enhancer-binding protein alpha axis. Utilizing liver-specific TKT overexpression and knockout mouse models, we demonstrated that TKT was sufficient and required for MAFLD progression. Further metabolic flux analysis revealed that Tkt deletion increased hepatic inosine levels to activate the protein kinase A-cAMP response element binding protein cascade, promote phosphatidylcholine synthesis, and improve mitochondrial function. Moreover, insulin induced hepatic TKT to limit inosine-dependent mitochondrial activity. Importantly, N-acetylgalactosamine (GalNAc)-siRNA conjugates targeting hepatic TKT showed promising therapeutic effects on mouse MAFLD. Our study uncovers how hyperinsulinemia regulates TKT-orchestrated inosine metabolism and mitochondrial function and provides a novel therapeutic strategy for MAFLD prevention and treatment.
Hepatocyte ALOXE3 is induced during adaptive fasting and enhances insulin sensitivity by activating hepatic PPARγ
The hepatic glucose fasting response is gaining traction as a therapeutic pathway to enhance hepatic and whole-host metabolism. However, the mechanisms underlying these metabolic effects remain unclear. Here, we demonstrate the epidermal-type lipoxygenase, eLOX3 (encoded by its gene, Aloxe3), is a potentially novel effector of the therapeutic fasting response. We show that Aloxe3 is activated during fasting, glucose withdrawal, or trehalose/trehalose analogue treatment. Hepatocyte-specific Aloxe3 expression reduced weight gain and hepatic steatosis in diet-induced and genetically obese (db/db) mouse models. Aloxe3 expression, moreover, enhanced basal thermogenesis and abrogated insulin resistance in db/db diabetic mice. Targeted metabolomics demonstrated accumulation of the PPARγ ligand 12-KETE in hepatocytes overexpressing Aloxe3. Strikingly, PPARγ inhibition reversed hepatic Aloxe3–mediated insulin sensitization, suppression of hepatocellular ATP production and oxygen consumption, and gene induction of PPARγ coactivator-1α (PGC1α) expression. Moreover, hepatocyte-specific PPARγ deletion reversed the therapeutic effect of hepatic Aloxe3 expression on diet-induced insulin intolerance. Aloxe3 is, therefore, a potentially novel effector of the hepatocellular fasting response that leverages both PPARγ-mediated and pleiotropic effects to augment hepatic and whole-host metabolism, and it is, thus, a promising target to ameliorate metabolic disease.
Using trehalose to prevent and treat metabolic function: effectiveness and mechanisms
Trehalose and its analogues are promising cardiometabolic therapeutic agents with pleiotropic effects across tissue types. It is likely that we are only beginning to uncover the broad efficacy and complex mechanisms by which these compounds modulate host metabolism.
Tagatose, the new GRAS sweetener and health product
Tagatose, a low-calorie natural sugar, has recently received FDA GRAS status, allowing its use as a sweetener in food and beverages. This paper provides an overview of tagatose, including its applications in food and beverages and potential health benefits. Safety studies conducted according to FDA guidelines support its GRAS status. Small clinical trials have shown tagatose to be effective in treating type 2 diabetes. It is a safe and effective low-calorie sweetener for various products, particularly those that require bulk, such as chocolates, gum, cakes, and ice cream. Tagatose can also complement high-intensity sweeteners in sodas. Additionally, it has potential health benefits, including treating diabetes, hyperglycemia, anemia, hemophilia, and supporting fetal development.
Temporal sweetness and side tastes profiles of 16 sweeteners using temporal check- all-that-apply (TCATA)
This study aimed to compare the temporal sweetness and qualitative differences of 15 sweeteners to sucrose. Various sweeteners from different groups were evaluated by 20 participants using the Temporal Check-all-that-Apply (TCATA) method. Sucrose exhibited a rapid onset of sweetness and minimal side tastes. Acesulfame-K, stevia, and luo han guo had prominent bitter, metallic, and chemical tastes. Allulose, erythritol, sorbitol, aspartame, and sucralose had some side tastes but maintained sweetness. Nutritive sweeteners like dextrose, fructose, maltitol, mannitol, sucrose-allulose mixture, palatinose, and xylitol had taste profiles most similar to sucrose in terms of sweetness onset, peak sweetness, decay, and side tastes. This information can help in selecting suitable sucrose substitutes based on taste profiles.
Rate-All-That-Apply (RATA) comparison of taste profiles for different sweeteners in black tea, chocolate milk, and natural yogurt
This study compared the taste properties of different sweeteners in three food matrices (black tea, chocolate milk, and natural yogurt) to sucrose. The sensory properties of each sweetener varied across the matrices, with some sweeteners closely resembling sucrose taste in all foods. Others had distinct taste profiles characterized by side tastes and lower sweetness. Sweeteners performed differently in natural yogurt compared to tea and chocolate milk. These findings emphasize the need to consider complex food matrices when selecting sweeteners as sugar substitutes. Food manufacturers can use these results to identify suitable sweetener substitutes for specific food products and support calorie reduction efforts.
Galactose enhances oxidative metabolism and reveals mitochondrial dysfunction in human primary muscle cells
This study looked at the differences in oxygen use when cells are nourished with glucose versus galactose. They saw a significant increase in oxygen utilisation with galactose, allowing them to characterise metabolic changes in diabetic patients, thereby creating a new model for the molecular mechanisms of mitochondrial dysfunction.
Galactose promotes fat mobilization in obese lactating and nonlactating women
American Journal of Clinical Nutrition published this study demonstrating the fat burning benefits of galactose: “Galactose consumption is associated with higher endogenous fat mobilization and oxidation during meal absorption”
The metabolome profiling and pathway analysis in metabolic healthy and abnormal obesity
This study aimed to identify metabolic pathways associated with different metabolic characteristics in obesity. Subjects with metabolic healthy obesity (MHO) and metabolic abnormal obesity (MAO) were analyzed using metabolomic profiling. Significant differences in metabolites and pathways were found between the MHO and MAO groups, providing insights into the development of abnormal metabolic phenotypes in obesity.
Tagatose, a new antidiabetic and obesity control drug
Early human studies suggested tagatose as a potential antidiabetic drug through its beneficial effects on postprandial hyperglycaemia and hyperinsulinaemia. A subsequent 14-month trial confirmed its potential for treating type 2 diabetes, and tagatose showed promise for inducing weight loss and raising high-density lipoprotein cholesterol, both important to the control of diabetes and constituting benefits independent of the disease.
Obesity and hyperinsulinemia drive adipocytes to activate a cell cycle program and senesce
Obesity leads to enlarged adipose tissue, and contrary to previous understanding, mature human adipocytes can enter an active cell cycle. However, chronic hyperinsulinemia triggers premature cell cycle exit and senescence in adipocytes. Targeting the adipocyte cell cycle with metformin may help reduce obesity-related inflammation.
Resistant starch intake facilitates weight loss in humans by reshaping the gut microbiota
This study investigated how adding resistant starch (RS), a type of dietary fiber, to the diet might help people with overweight or obesity. They conducted a trial with 37 participants and found that taking RS supplements for 8 weeks led to weight loss (an average of 2.8 kilograms) and improved insulin resistance. These benefits were linked to changes in the composition of gut bacteria. Specifically, a type of bacteria called Bifidobacterium adolescentis seemed to play a key role. When this bacteria was supplemented in male mice, it protected them from becoming obese on a high-calorie diet. The study suggests that RS alters the gut bacteria, which in turn affects various processes in the body such as bile acid levels, inflammation, and fat absorption, ultimately aiding in weight loss. This highlights the importance of gut bacteria in the beneficial effects of RS on weight loss and metabolic health.
Erythritol is a pentose-phosphate pathway metabolite and associated with adiposity gain in young adults
This study investigated metabolomic markers associated with the development of central adiposity in young adults. Participants with incident central adiposity gain had higher levels of blood erythritol compared to those with stable adiposity. Participants with higher baseline hemoglobin A1c (HbA1c) levels also had significantly higher blood erythritol. Erythritol was found to be synthesized from glucose through the pentose-phosphate pathway, suggesting its potential role in the association between erythritol and obesity in young adults.
Letter Regarding Article, “Metabolomic Pattern Predicts Incident Coronary Heart Disease”
This article discusses the use of erythritol, a metabolite, as a predictive marker for coronary heart disease. Erythritol is a naturally occurring noncaloric sweetener and not an artificial sweetener. The presence of erythritol in blood samples cannot be explained by its consumption as a sugar replacement. Studies have shown an association between erythritol levels and impaired glycemic control and central adiposity. The conversion of glucose to erythritol via the pentose-phosphate pathway may play a role in reflecting impaired glycemic control and its related complications. Further research is needed to fully understand the connection between erythritol concentrations and these health conditions.
Galactose increases mitochondrial activity which induces fat mobilisation and fat burning
This study focused on the role of transketolase (TKT) in colorectal cancer. The researchers found that TKT expression was significantly increased in colorectal cancer and correlated with poor prognosis. TKT was found to promote cancer cell growth and metastasis by interacting with GRP78 and enhancing glycolysis through AKT phosphorylation. These findings suggest that TKT could serve as a prognostic indicator for colorectal cancer and potentially be targeted for the development of new treatment strategies.
Consumption of Soft Drinks and Overweight and Obesity Among Adolescents in 107 Countries and Regions
This scientific article examines the relationship between soft drink consumption and the prevalence of overweight and obesity in adolescents. The study analysed data from 107 countries and regions, including a total of 405,528 school-going adolescents. The findings revealed that there was a positive correlation between the prevalence of daily soft drink consumption and the prevalence of overweight and obesity among adolescents. The analysis indicated a statistically significant association between daily soft drink consumption and overweight and obesity in school-going adolescents. The study suggests that reducing soft drink consumption should be a priority in addressing the issue of adolescent overweight and obesity.
Ketogenic diet – a literature review
The ketogenic diet has gained attention for its potential benefits in various health conditions. It has been found to aid in weight reduction, improve lipid profile, and potentially reduce the need for antidiabetic drugs and insulin therapy in type 2 diabetes. Animal studies suggest positive effects in cancer treatment, although human studies are limited. Additionally, there are reports of the ketogenic diet delaying the onset of dementia symptoms. However, the long-term impact on cardiovascular risk is still unknown, emphasizing the need for careful consideration before adopting the diet.
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