Dietary Fructose and Fructose-Induced Pathologies

The Probiotic Effects of Lactobacillus brevis CD2 on Caries Related Variables of Dental Plaque Biofilm

OBJECTIVES

This study was based on the research question: "Does L. brevis CD2 have an effect on the acidogenicity of sugar-exposed bacteria? To solve this question, a multistep study was planned: first, an in vitro investigation aimed to assess the acid production of monoculture bacterial solutions; and second, an ex vivo experiment to evaluate the production or inhibition of acids from plaque samples.

METHODS

L. brevis CD2 and several control strains (Lactobacillus brevis CD2, Lactobacillus reuteri DSM 17938, Lactobacillus rhamnosus LB21, Lactobacillus plantarum 931, Streptococcus mutans Ingbritt) were tested with various sugars; pH changes were recorded at specific time points using a micro-pH electrode. Additionally, for the ex vivo phase, the same sugars were added to equal amounts of pooled plaque from 9 healthy subjects with bacterial suspensions, as well as a control solution, and pH was monitored for up to 90 minutes. For the ex vivo phase, 9 adults were randomised in a crossover design for 28 days. For the in vivo phase, 26 healthy subjects used 1/2 lozenges 3 times daily containing either L. brevis CD2 (active) or no probiotic bacteria (placebo). Plaque acidogenicity was assessed using the microtouch method after a 10 ml mouth rinse containing 10% sucrose for 1 minute (on day 0 and day 28).

RESULTS

L. brevis CD2 exhibited the highest ability to inhibit the fermentation of fructose, lactose, and sucrose compared to the control strains (P < .05). A significant reduction in plaque acidogenicity was observed in vivo from day 0 to day 28 in the test group (P < .05).

CONCLUSIONS

This study indicates that L. brevis CD2 mitgates the acidogenic attributes of plaque biofilm organisma in vitro, in vivo and ex vivo, suggesting its potential benefit as a caries preventive probiotic agent.

The Hepatic Axis Fructose-Methylglyoxal-AMPK: Starring or Secondary Role in Chronic Metabolic Disease?

Biochemical alterations linked to metabolic syndrome (MetS), type 2 diabetes (T2DM), and metabolic dysfunction-associated steatotic liver disease (MASLD) may be brought on by the Western diet. Based on research conducted over the past decade, fructose is one of the main culprits. Over 80% of ingested fructose is metabolized by the liver at first pass, where it stimulates de novo lipogenesis (DNL) to drive hepatic triglyceride (TG) synthesis, which contributes to MASLD, hepatic insulin resistance (IR), and dyslipidemia. Fructose reduction produces quick and significant amelioration in these metabolic disturbances. We hereby propose potential overarching processes that can link these pathways to signaling disruption by the critical metabolic sensor AMP-activated protein kinase (AMPK). We proffer that when large amounts of fructose and glucose enter the liver, triose fluxes may be sufficient to produce transient increases in methylglyoxal (MG), allowing steady-state concentrations between its production and catabolism by glyoxalases to be high enough to modify AMPK-sensitive functional amino acid residues. These reactions would transiently interfere with AMPK activation by both AMP and aldolase. Such a sequence of events would boost the well-documented lipogenic impact of fructose. Given that MG adducts are irreversible, modified AMPK molecules would be less effective in metabolite sensing until they were replaced by synthesis. If proven, this mechanism provides another avenue of possibilities to tackle the problem of fructose in our diet. We additionally discuss potential multimodal treatments and future research avenues for this apparent hepatic AMPK malfunction.

Exploring Glyoxalase Strategies for Managing Sugar-Induced Chronic Diseases

The liver's crucial role in methylglyoxal (MG) metabolism is frequently overlooked in the literature. We present a perspective that enhances the current understanding of the role of methylglyoxal (MG) and the glyoxalase cycle in the pathogenesis of insulin resistance and obesity, ultimately leading to type 2 diabetes mellitus (DM) and cardiovascular disease (CVD). Fructose may be a significant substrate contributing, particularly in contemporary times, to the flux of trioses in the liver, accounting for a substantial portion of MG production. The steady-state concentration of MG-and the subsequent modification of proteins-would then be determined by the flux of trioses, their utilization in lipogenesis, and their decomposition into MG, which is further converted into D-lactate by glyoxalase enzymes GLO1 and GLO2. Consequently, enhancing the activity and/or expression of GLO1 could potentially mitigate the adverse effects of fructose in the liver. Additional research and validation are required to confirm these biological pathways. These arguments are in favor of further research into safe and efficient ways to activate the glyoxalase pathway to lessen the negative effects of fructose metabolism that lead to insulin resistance (IR) and its related repercussions.

Nutrition and Neuroinflammation: Are Middle-Aged Women in the Red Zone?

Women exhibit unique vulnerabilities in health, especially regarding mental health and neurodegenerative diseases. Biological, hormonal, and metabolic differences contribute to sex-specific risks that remain underrepresented in clinical studies. Diseases such as major depressive disorder (MDD) and Alzheimer's disease (AD) are more prevalent in women and may be influenced by hormonal transitions, particularly during menopause. Chronic low-grade inflammation is emerging as a shared mechanism underlying both conditions, and this inflammatory state can be worsened by dietary habits. During menopause, mood and sleep disturbances can influence dietary behavior, leading to enhanced snacking and consumption of high-glycemic and comfort foods. Such foods, low in nutritional value, promote weight gain and elevated inflammatory markers. Their consumption combined (or not) with a preexisting Western diet pattern-already linked to inflammation-could reinforce systemic inflammation involving the gut-brain axis. Moreover, the symptoms "per se" could act on inflammation as well. Peripheral inflammation may cross the blood-brain barrier, sustaining mood disorders and promoting neurodegenerative changes. Finally, MDD and AD are both associated with conditions such as obesity and diabetes, which occur more frequently in women. The review highlights how menopause-related changes in mood, sleep, and diet may heighten susceptibility to mental and neurodegenerative diseases.

Excess Fructose Intake Activates Hyperinsulinemia and Mitogenic MAPK Pathways in Association With Cellular Stress, Inflammation, and Apoptosis in the Pancreas of Rats

The increase in sugar consumption has been associated with current metabolic disease epidemics. This study aimed to investigate the pancreatic molecular mechanisms involved in cellular stress, inflammation, mitogenesis, and apoptosis in metabolic disease induced by high-fructose diet. Here, we used biochemical, histopathological, Western blot, and immunohistochemistry methods to determine the metabolic and pancreatic alterations in male Wistar rats fed 20% fructose in drinking water for 15 weeks. High-fructose consumption in rats increased the immunopositivity and protein expression of glucose transporter 2 (GLUT2) and insulin in the pancreatic tissue, in association with abdominal adiposity, hyperglycemia, and hypertriglyceridemia. The expressions of cellular stress markers, glucose-regulated protein-78 (GRP78) and PTEN-induced putative kinase 1 (PINK1), were increased in the pancreas. The levels of interleukin (IL)-6, nuclear factor kappa B (NFκB), tumor necrosis factor α (TNFα), and IL-1β and components of the Nod-like receptor protein 3 (NLRP3) inflammasome were elevated. Excess fructose intake stimulated the activation of mitogenic extracellular signal-regulated kinases 1/2 (ERK1/2), p38, and c-Jun N-terminal kinase (JNK)1 as well as the apoptotic p53 and Fas pathways in the pancreas of rats. There was also an increase in caspase-8 and caspase-3 cleavage. Our findings revealed that dietary high-fructose in the pancreas causes hyperinsulinemia due to the upregulation of GLUT2 together with cellular stress and inflammatory markers, thereby stimulates mitogenic mitogen-activated protein kinase (MAPK) and apoptosis pathways, resulting in a complex pathological situation.

Pharmacophore-based virtual screening and in silico investigations of small molecule library for discovery of human hepatic ketohexokinase inhibitors for the treatment of fructose metabolic disorders

Introduction

Excessive fructose consumption is a significant driver of metabolic disorders, including obesity, diabetes, non-alcoholic fatty liver disease and non-alcoholic steatohepatitis primarily by promoting insulin resistance and fat accumulation. Ketohexokinase C (KHK-C), a pivotal enzyme in fructose metabolism, catalyzes the phosphorylation of fructose to fructose-1-phosphate, initiating a cascade of downstream metabolic processes. In contrast to glucose metabolism, KHK-C lacks negative feedback regulation, allowing the continuous phosphorylation of fructose, which leads to heightened levels of glucose, glycogen, and triglycerides in the bloodstream and liver. While targeting KHK-C offers a promising therapeutic avenue, no drugs have yet been approved for clinical use. Pfizer's PF-06835919 has progressed to phase II trials, demonstrating a reduction in liver fat and improved insulin sensitivity, while Eli Lilly's LY-3522348 also shows significant potential. Nonetheless, there remains a critical need for the development of novel KHK-C inhibitors that offer improved pharmacokinetics, enhanced efficacy, and superior safety profiles.

Methods

In the present study, a comprehensive computational strategy was employed to screen 460,000 compounds from the National Cancer Institute library for potential KHK-C inhibitors. Initially, pharmacophore-based virtual screening was used to identify potential hits, followed by multi-level molecular docking, binding free energy estimation, pharmacokinetic analysis, and molecular dynamics (MD) simulations to further evaluate the compounds. This multi-step approach aimed to identify compounds with strong binding affinity, favorable pharmacokinetic profiles, and high potential for efficacy as KHK-C inhibitors.

Results

Ten compounds exhibited docking scores ranging from -7.79 to -9.10 kcal/mol, surpassing those of the compounds currently undergoing clinical trials, PF-06835919 (-7.768 kcal/mol) and LY-3522348 (-6.54 kcal/mol). Their calculated binding free energies ranged from -57.06 to -70.69 kcal/mol, further demonstrating their superiority over PF-06835919 (-56.71 kcal/mol) and LY-3522348 (-45.15 kcal/mol). ADMET profiling refined the selection to five compounds (1, 2, and 4-6), and molecular dynamics simulations identified compound 2 as the most stable and promising candidate compared to the clinical candidate PF-06835919.

Conclusion

These findings highlight compound 2 as a potent KHK-C inhibitor with predicted pharmacokinetics and toxicity profiles supporting its potential for treating fructose-driven metabolic disorders, warranting further validation.

Paternal Cyanidin-3-O-Glucoside Diet Improved High-Fat, High-Fructose Diet-Induced Intergenerational Inheritance in Male Offspring's Susceptibility to High-Fat Diet-Induced Testicular and Sperm Damage

High-fructose and high-fat diet (HFHFD) has been associated with impaired spermatogenesis, leading to decreased sperm quality and increased male infertility, with similar effects observed in offspring. Cyanidin-3-O-glucoside (C3G), a recognized food antioxidant, has shown promise in protecting in male reproduction and modulating epigenetic modifications. However, its potential role in ameliorating intergenerational inheritance induced by HFHFD remains underexplored. In this study, we investigated the effects of paternal HFHFD on reproductive injury of offspring and the protective effect of C3G. Paternal mice were subjected to 12 weeks of HFHFD induction and C3G treatment was conducted for 8 weeks. Offspring obtained via in vitro fertilization were fed either a normal diet (ND) or high-fat diet (HFD). Our findings indicate that while the paternal HFHFD did not result in observable reproductive impairments in paternal mice, it did affect offspring testicular function through intergenerational inheritance, rendering them more susceptible to testicular damage and reduced sperm counts when exposed to an HFD. Notably, C3G intervention significantly mitigated these effects, suggesting its potential as a therapeutic compound for alleviating the impact of paternal intergenerational inheritance on male fertility resulting from HFHFD. These results underscore the importance of further exploring the mechanisms underlying intergenerational inheritance and the potential of interventions such as C3G in mitigating its effects, with implications for both basic research and clinical practice.

Mitochondria at the Crossroads: Linking the Mediterranean Diet to Metabolic Health and Non-Pharmacological Approaches to NAFLD

Nonalcoholic fatty liver disease (NAFLD) is a growing global health concern that is closely linked to metabolic syndrome, yet no approved pharmacological treatment exists. The Mediterranean diet (MD) emerged as a first-line dietary intervention for NAFLD, offering metabolic and hepatoprotective benefits. Now conceptualized as a complex chemical matrix rich in bioactive compounds, the MD exerts antioxidant and anti-inflammatory effects, improving insulin sensitivity and lipid metabolism. Mitochondria play a central role in NAFLD pathophysiology, influencing energy metabolism, oxidative stress, and lipid homeostasis. Emerging evidence suggests that the MD's bioactive compounds enhance mitochondrial function by modulating oxidative phosphorylation, biogenesis, and mitophagy. However, most research has focused on individual compounds rather than the MD as a whole, leaving gaps in understanding its collective impact as a complex dietary pattern. This narrative review explores how the MD and its bioactive compounds influence mitochondrial health in NAFLD, highlighting key pathways such as mitochondrial substrate control, dynamics, and energy efficiency. A literature search was conducted to identify relevant studies on the MD, mitochondria, and NAFLD. While the search was promising, our understanding remains incomplete, particularly when current knowledge is limited by the lack of mechanistic and comprehensive studies on the MD's holistic impact. Future research integrating cutting-edge experimental approaches is needed to elucidate the intricate diet-mitochondria interactions. A deeper understanding of how the MD influences mitochondrial health in NAFLD is essential for developing precision-targeted nutritional strategies that can effectively prevent and manage the disease.

A Novel Mouse Model of Type 2 Diabetes Using a Medium-Fat Diet, Fructose, and Streptozotocin to Study the Complications of Human Disease

The study of type 2 diabetes mellitus (T2DM) pathophysiology relies mainly on the use of animal models, the most common of which involves the consumption of high-fat diets comprising 60% calories from fat. Although these models reproduce the onset and most complications associated with T2DM, they do not accurately mimic human dietary patterns, as they lack the addition of carbohydrates such as fructose. This study aimed to develop a C57BL/6 mouse model of T2DM that mimics the disease, as occurs in younger individuals, via a medium-fat diet (34.5% kcal from fat) combined with a 20% fructose solution as drinking water and a single low-dose of streptozotocin (STZ) (100 mg/kg), a diabetogenic drug. At week 20, D + T mice exhibited significant weight gain and elevated fasting blood glucose levels compared with those of control mice and the development of insulin resistance. Similarly, the circulating levels of hepatic enzymes (GPT, GOT, and alkaline phosphatase), total cholesterol, and LDL increased. Multi-organ damage, including reduced pancreatic islet size and number, severe hepatic steatosis, inflammatory infiltration in visceral adipose tissue, and cardiac and renal dysfunction, were also detected. The proposed model replicates T2DM in young mice by combining a medium-fat diet with fructose and STZ.

Sugar-sweetened beverage intake, gut microbiota, circulating metabolites, and diabetes risk in Hispanic Community Health Study/Study of Latinos

No population-based studies examined gut microbiota and related metabolites associated with sugar-sweetened beverage (SSB) intake among US adults. In this cohort of US Hispanic/Latino adults, higher SSB intake was associated with nine gut bacterial species, including lower abundances of several short-chain-fatty-acid producers, previously shown to be altered by fructose and glucose in animal studies, and higher abundances of fructose- and glucose-utilizing Clostridium bolteae and Anaerostipes caccae. Fifty-six serum metabolites were correlated with SSB intake and a gut microbiota score based on these SSB-related species in consistent directions. These metabolites were clustered into several modules, including a glycerophospholipid module, two modules comprising branched-chain amino acid (BCAA) and aromatic amino acid (AAA) derivatives from microbial metabolism, etc. Higher glycerophospholipid and BCAA derivative levels and lower AAA derivative levels were associated with higher incident diabetes risk during follow-up. These findings suggest a potential role of gut microbiota in the association between SSB intake and diabetes.

Glycaemic sugar metabolism and the gut microbiota: past, present and future

Non-communicable diseases (NCDs), such as type 2 diabetes (T2D) and metabolic dysfunction-associated fatty liver disease, have reached epidemic proportions worldwide. The global increase in dietary sugar consumption, which is largely attributed to the production and widespread use of cheap alternatives such as high-fructose corn syrup, is a major driving factor of NCDs. Therefore, a comprehensive understanding of sugar metabolism and its impact on host health is imperative to rise to the challenge of reducing NCDs. Notably, fructose appears to exert more pronounced deleterious effects than glucose, as hepatic fructose metabolism induces de novo lipogenesis and insulin resistance through distinct mechanisms. Furthermore, recent studies have demonstrated an intricate relationship between sugar metabolism and the small intestinal microbiota (SIM). In contrast to the beneficial role of colonic microbiota in complex carbohydrate metabolism, sugar metabolism by the SIM appears to be less beneficial to the host as it can generate toxic metabolites. These fermentation products can serve as a substrate for fatty acid synthesis, imposing negative health effects on the host. Nevertheless, due to the challenging accessibility of the small intestine, our knowledge of the SIM and its involvement in sugar metabolism remains limited. This review presents an overview of the current knowledge in this field along with implications for future research, ultimately offering potential therapeutic avenues for addressing NCDs.

Nutraceutical Potential and Food Safety of Fructose in Soda and Diet Beverages

Fructose has been considered as an additive from soda beverages. For the approval of new additives or to extend the usage of an approved one, it is necessary to conduct toxicological studies in order to evaluate the DNA damage induced by these compounds. Our study is based on evaluating the safety and the nutraceutical potential of Fructose (FRU), a soda cola beverage (Pepsi-cola, PEP), and a diet soda cola (Diet Coke, DCC), characterizing the DNA changes induced in the Drosophila melanogaster organism model and in the human leukemia HL-60 cells performing different assays. Our results showed neither the toxicity nor mutagenic activity of FRU, PEP, and DCC in Drosophila melanogaster, while only PEP exhibited protective effects in the antitoxity assay, showing an 80% survival rate in combined treatments. FRU, but not PEP, enhanced lifespan parameters by up to 23 more days at the 5 mg/mL concentration. All three substances exhibited chemopreventive properties in some of the checkpoints carried out related to clastogenicity and methylation patterns in HL-60 cells. In conclusion, the tested compounds were safe at tested concentrations in Drosophila and showed moderate chemopreventive activity.

Fructose catabolism and its metabolic effects: Exploring host-microbiota interactions and the impact of ethnicity

Important health disparities are observed in the prevalence of obesity and associated non-communicable diseases (NCDs), including type 2 diabetes (T2D) and metabolic dysfunction-associated steatotic liver disease (MASLD) among ethnic groups. Yet, the underlying factors accounting for these disparities remain poorly understood. Fructose has been widely proposed as a potential mediator of these NCDs, given that hepatic fructose catabolism can result in deleterious metabolic effects, including insulin resistance and hepatic steatosis. Moreover, the fermentation of fructose by the gut microbiota can produce metabolites such as ethanol and acetate, both which serve as potential substrates for de novo lipogenesis (DNL) and could therefore contribute to the development of these metabolic conditions. Significant inter-ethnic differences in gut microbiota composition have been observed. Moreover, fructose consumption varies across ethnic groups, and fructose intake has been demonstrated to significantly alter gut microbiota composition, which can influence its fermenting properties and metabolic effects. Therefore, ethnic differences in gut microbiota composition, which may be influenced by variations in fructose consumption, could contribute to the observed health disparities. This review provides an overview of the complex interactions between host and microbial fructose catabolism, the role of ethnicity in shaping these metabolic processes and their impact on host health. Understanding these interactions could provide insights into the mechanisms driving ethnic health disparities to improve personalized nutrition strategies. KEY POINTS: Dietary fructose consumption has increased substantially over recent decades, which has been associated with the rising prevalence of obesity and non-communicable diseases (NCDs) such as type 2 diabetes and metabolic dysfunction-associated steatotic liver disease. Pronounced disparities among different ethnic groups in NCD prevalence and dietary fructose consumption underscore the need to elucidate the underlying mechanisms of fructose catabolism and its health effects. Together with the well-known toxic effects of hepatic fructose catabolism, emerging evidence highlights a role for the small intestinal microbiota in fermenting sugars like fructose into various bacterial products with potential deleterious metabolic effects. There are significant ethnic differences in gut microbiota composition that, combined with varying fructose consumption, could mediate the observed health disparities. To comprehensively understand the role of the gut microbiota in mediating fructose-induced adverse metabolic effects, future research should focus on the small intestinal microbiota. Future research on fructose - microbiota - host interactions should account for ethnic differences in dietary habits and microbial composition to elucidate the potential role of the gut microbiota in driving the mentioned health disparities.

Inter-organ metabolic interaction networks in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multisystem metabolic disorder, marked by abnormal lipid accumulation and intricate inter-organ interactions, which contribute to systemic metabolic imbalances. NAFLD may progress through several stages, including simple steatosis (NAFL), non-alcoholic steatohepatitis (NASH), cirrhosis, and potentially liver cancer. This disease is closely associated with metabolic disorders driven by overnutrition, with key pathological processes including lipid dysregulation, impaired lipid autophagy, mitochondrial dysfunction, endoplasmic reticulum (ER) stress, and local inflammation. While hepatic lipid metabolism in NAFLD is well-documented, further research into inter-organ communication mechanisms is crucial for a deeper understanding of NAFLD progression. This review delves into intrahepatic networks and tissue-specific signaling mediators involved in NAFLD pathogenesis, emphasizing their impact on distal organs.

Comparative effects of viable Lactobacillus rhamnosus GG and its heat-inactivated paraprobiotic in the prevention of high-fat high-fructose diet-induced non-alcoholic fatty liver disease in rats

Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver alterations worldwide, being gut microbiota dysbiosis one of the contributing factors to its development. The aim of this research is to compare the potential effects of a viable probiotic (Lactobacillus rhamnosus GG) with those exerted by its heat-inactivated paraprobiotic counterpart in a dietary rodent model of NAFLD. The probiotic administration effectively prevented the hepatic lipid accumulation induced by a high-fat high-fructose diet feeding, as demonstrated by chemical (lower TG content) and histological (lower steatosis grade and lobular inflammation) analyses. This effect was mainly mediated by the downregulation of lipid uptake (FATP2 protein expression) and upregulating liver TG release to bloodstream (MTTP activity) in rats receiving the probiotic. By contrast, the effect of the paraprobiotic preventing diet-induced liver lipid accumulation was milder, and mainly derived from the downregulation of hepatic de novo lipogenesis (SREBP-1c protein expression and FAS activity) and TG assembly (DGAT2 and AQP9 protein expression). The obtained results demonstrate that under these experimental conditions, the effects induced by the administration of viable L. rhamnosus GG preventing liver lipid accumulation in rats fed a diet rich in saturated fat and fructose differ from those induced by its heat-inactivated paraprobiotic counterpart.

Bioactive metabolites: A clue to the link between MASLD and CKD?

Metabolites produced as intermediaries or end-products of microbial metabolism provide crucial signals for health and diseases, such as metabolic dysfunction-associated steatotic liver disease (MASLD). These metabolites include products of the bacterial metabolism of dietary substrates, modification of host molecules (such as bile acids [BAs], trimethylamine-N-oxide, and short-chain fatty acids), or products directly derived from bacteria. Recent studies have provided new insights into the association between MASLD and the risk of developing chronic kidney disease (CKD). Furthermore, alterations in microbiota composition and metabolite profiles, notably altered BAs, have been described in studies investigating the association between MASLD and the risk of CKD. This narrative review discusses alterations of specific classes of metabolites, BAs, fructose, vitamin D, and microbiota composition that may be implicated in the link between MASLD and CKD.

Suboptimal vitamin D status and overweight/obesity are associated with gut integrity and inflammation in minority children and adolescents: A cross-sectional analysis from the MetA-bone trial

Preserving gut integrity is essential to preventing the development of chronic diseases. Several factors are associated with gut integrity and inflammation in adults. However, there is limited evidence in healthy children. This study evaluated the factors associated with gut integrity and inflammation in healthy children participating in the MetA-Bone trial. We hypothesized that age, sex, race/ethnicity, diet, vitamin D, and body composition will be associated with gut integrity and inflammation. Socio-demographic variables were collected with a questionnaire. Measures included markers of gut integrity (Intestinal Fatty Acid Binding Protein; I-FABP), and inflammation (IL-17 and calprotectin) determined by ELISA in 24-h urine and serum; serum 25(OH)D concentration (commercial lab), BMI percentile, and diet (24-h recalls). Analyses included descriptive statistics, chi-square, and adjusted logistic regressions. Participants (n=138) median age was 12.4 (11.1-13.3), 53.6% were male, 9.4% were Black/African American, and 71.1% were Hispanic/Latino. Children with suboptimal vitamin D were 3.35 times more likely to present gut integrity damage (elevated I-FABP) than those with optimal status (P = .005). Overweight/obesity and fructose intake were associated with inflammation (elevated calprotectin) (P < .05). Those with lower gut integrity damage had lower odds of having higher inflammation (P = .021). Other factors were not associated with inflammation. Suboptimal vitamin D status, overweight/obesity and inflammation may compromise the gut integrity in healthy children, suggesting an impairment on the intestinal barrier repair system. More research with a longitudinal design is needed to gain a deeper understanding of the role of additional factors linked to gut integrity and inflammation in healthy children.

Effect of Acacia Honey on Serum Uric Acid Level and Liver Injury in Rats

Objective

Honey is generally considered to be a natural product with rich nutritional value. However, the fructose contained in honey is harmful to the liver. This study aims to observe the effect of acacia honey (AH) on serum uric acid and liver injury in potassium oxonate model rats after drinking AH aqueous solution.

Materials and methods

Sixty male Sprague-Dawley (SD) rats were selected and randomly divided into control group (CON group), potassium oxonate model group (OA model group), 10% fructose group (10%F group) and different concentration AH groups (25%, 12.5% and 6.25% AH groups). 100 mg/kg OA solution combined with fructose solution or AH solution was administered to gavage model rats. After the 4 weeks test, blood and liver tissues were collected, serum uric acid content, biochemical indexes, activities of alanine transaminase and alanine transaminase were determined, and liver histological sections were observed.

Results

AH can significantly increase serum uric acid level, liver weight and liver to body weight ratio ( p < 0.05). The levels of serum triglyceride (TG), free fatty acid (FFA), and high-density fatty acid cholesterol (HDL-C) were elevated in 25% and 12.5% AH groups compared with CON group or OA model group ( p < 0.05), but serum levels of TG, FFA, HDL-C, total cholesterol (T-CHO) and low density lipoprotein cholesterol (LDL-C) were significantly increased in 6.25%AH group ( p < 0.05).

Conclusion

AH can cause fatty liver disease in all rats in a dose dependent manner. In the dose range of the present study, AH can induce hyperuricemia, hypertriglyceridemia and fatty liver disease.

Which dietary patterns fend off nonalcoholic fatty liver disease? A systematic review of observational and interventional studies

BACKGROUND

The global burden of non-alcoholic fatty liver disease (NAFLD) has significantly risen over the past decade. Dietary intake strongly influences its development and should be a component of any prevention and treatment plan strategy. Dietary pattern analysis enables the investigation of the overall diet and permits the consideration of interactions and cumulative effects of dietary components. The current study aimed to systematically review observational studies and intervention trials to determine the associations between various dietary patterns and NAFLD.

METHODS

The protocol was written according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched PubMed, Embase, and the Cochrane Library. We included studies that reported a priori dietary pattern (i.e., diet quality scores) or a posteriori method, which identified existing eating patterns (i.e., principal component analysis) in adult participants. Two investigators conducted independent screening, extraction, and quality assessment using the Newcastle‒Ottawa or Jadad scale. A third reviewer resolved conflicts.

RESULTS

We identified 27 relevant observational and 16 interventional studies from 16 countries. A Mediterranean or DASH diet might prevent and improve NAFLD, whereas dietary patterns such as Western dietary patterns characterized by high consumption of sweets and animal foods such as red meat and fast food are positively associated with NAFLD. A low-carbohydrate diet effectively prevents and treats NAFLD; however, we need more research on the effects of a low-fat diet and the type of fats.

CONCLUSION

Healthy dietary patterns, mainly plant-based or adjusted macronutrient distributions, such as the adoption of a low-carbohydrate diet, are linked to a reduced risk of NAFLD and could halt its progression. We proposed recommendations for future studies to fill the gap in knowledge regarding the management of NAFLD via dietary modifications.

Nicotinamide Riboside Ameliorates Fructose-Induced Lipid Metabolism Disorders in Mice by Activating Browning of WAT, and May Be Also Related to the Regulation of Gut Microbiota

OBJECTIVES

This study aims to observe the preventive effect of nicotinamide riboside (NR) on fructose-induced lipid metabolism disorders and explore its mechanism.

METHODS

Male C57BL/6J mice were fed a 20% fructose solution and given 400 mg/kg NR daily by gavage for 10 weeks.

RESULTS

The results indicated that NR supplementation significantly reduced the body weight, liver weight, white adipose tissue (WAT) weight, serum, and hepatic lipid levels. NR upregulated the protein expression levels of sirtuin-1 (SIRT1), AMP-activated protein kinase (AMPK), PR domain containing 16 (PRDM16), uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor-gamma coactiva-tor-1-alpha (PGC-1α), nuclear respiratory factor 1-encoding gene (NRF1), mitochondrial transcription factor A (TFAM), cluster of differentiation 137 (CD137), transmembrane protein 26 (TMEM26), and T-box 1 (TBX1). Moreover, NR enhanced the Actinobacteria and Enterorhabdus abundance. Spearman's correlation analysis revealed that significant correlations exist between Firmicutes, Bacteroidetes, and Erysipelotrichaceae with browning-related indicators.

CONCLUSIONS

In conclusion, NR could alleviate lipid metabolic abnormalities induced by fructose through activating SIRT1/AMPK-mediated browning of WAT. The mechanism by which NR improves fructose-induced lipid metabolism disorders may also be associated with the modulation of intestinal flora.

Advances in research on the role of high carbohydrate diet in the process of inflammatory bowel disease (IBD)

Inflammatory bowel disease (IBD) is a chronic, systemic gastrointestinal disorder characterized by episodic inflammation that requires life-long management. Although the etiology of IBD is not fully understood, it is hypothesized to involve a multifaceted interplay among genetic susceptibility, the host immune response, and environmental factors. Previous studies have largely concluded that IBD is associated with this complex interplay; however, more recent evidence underscores the significant role of dietary habits as risk factors for the development of IBD. In this review, we review the molecular mechanisms of high-sugar and high-fat diets in the progression of IBD and specifically address the impacts of these diets on the gut microbiome, immune system regulation, and integrity of the intestinal barrier, thereby highlighting their roles in the pathogenesis and exacerbation of IBD.

Hydroxytyrosol's Protective Effect Through Podocalyxin and Pentraxin-3 in Kidney Damage Resulting From Corn Syrup Administration

INTRODUCTION

In this study, we aimed to investigate whether hydroxytyrosol (HT) has a protective effect on corn syrup-induced kidney damage in rats and the role of podocalyxin (PCX) and pentraxin-3 (PTX3) in this possible effect.

METHODS

Rats were divided into four groups with six rats in each group: 1) control, 2) HT, 3) corn syrup, and 4) corn syrup + HT. Rats were given 30% corn syrup added to their drinking water for six weeks. HT was given orally at 4 ml/kg/day, alone and together with corn syrup. PCX and PTX3 in the renal tissue were assessed through histopathological examination. Biochemical parameters were also examined in the sera with the ELISA method.

RESULTS

In this study, it was observed that PCX and PTX3 levels, which increased as a result of corn syrup administration, decreased after HT treatment (p < 0.001). The increase in amylase, lipase, and insulin levels because of corn syrup consumption decreased with HT consumption (p = 0.001, p < 0.001, p = 0.003, respectively). It was determined that the increase in erythrocyte extravasation, exudate accumulation, and fibrosis observed in the kidney tissue with corn syrup application decreased as a result of HT application (p < 0.001).

CONCLUSION

It is thought that HT has a protective effect against kidney damage caused by corn syrup and that PCX and PTX3 may play a role in this effect.

Discovery of BI-9787, a potent zwitterionic ketohexokinase inhibitor with oral bioavailability

Fructose metabolism by ketohexokinase (KHK) is implicated in a variety of metabolic disorders. KHK inhibition is a potential therapeutic strategy for the treatment of diseases including diabetes, non-alcoholic fatty liver disease, and non-alcoholic steatohepatitis. The first small-molecule KHK-inhibitors have entered clinical trials, but it remains unclear if systemic inhibition of KHK by small-molecules will eventually benefit patients. Here we report the discovery of BI-9787, a potent, zwitterionic KHK inhibitor characterized by high permeability and favorable oral rat pharmacokinetics. BI-9787 was identified by optimizing chemical starting points generated via a ligand-based virtual screening of Boehringer's virtual library of synthetically accessible compounds (BICLAIM). It serves as a high-quality in vitro and in vivo tool compound for investigating the role of fructose metabolism in disease.

Protective role of cells and spores of Shouchella clausii SF174 against fructose-induced gut dysfunctions in small and large intestine

The oral administration of probiotics is nowadays recognized as a strategy to treat or prevent the consequences of unhealthy dietary habits. Here we analyze and compare the effects of the oral administration of vegetative cells or spores of Shouchella clausii SF174 in counteracting gut dysfunctions induced by 6 weeks of high fructose intake in a rat model. Gut microbiota composition, tight junction proteins, markers of inflammation and redox homeostasis were evaluated in ileum and colon in rats fed fructose rich diet and supplemented with cells or spores of Shouchella clausii SF174. Our results show that both spores and cells of SF174 were effective in preventing the fructose-induced metabolic damage to the gut, namely establishment of "leaky gut", inflammation and oxidative damage, thus preserving gut function. Our results also suggest that vegetative cells and germination-derived cells metabolize part of the ingested fructose at the ileum level.

6-Gingerol Inhibits De Novo Lipogenesis by Targeting Stearoyl-CoA Desaturase to Alleviate Fructose-Induced Hepatic Steatosis

Metabolic-associated fatty liver disease (MAFLD), also known as non-alcoholic fatty liver disease (NAFLD), is a worldwide liver disease without definitive or widely used therapeutic drugs in clinical practice. In this study, we confirm that 6-gingerol (6-G), an active ingredient of ginger (Zingiber officinale Roscoe) in traditional Chinese medicine (TCM), can alleviate fructose-induced hepatic steatosis. It was found that 6-G significantly decreased hyperlipidemia caused by high-fructose diets (HFD) in rats, and reversed the increase in hepatic de novo lipogenesis (DNL) and triglyceride (TG) levels induced by HFD, both in vivo and in vitro. Mechanistically, chemical proteomics and cellular thermal shift assay (CETSA)-proteomics approaches revealed that stearoyl-CoA desaturase (SCD) is a direct binding target of 6-G, which was confirmed by further CETSA assay and molecular docking. Meanwhile, it was found that 6-G could not alter SCD expression (in either mRNA or protein levels), but inhibited SCD activity (decreasing the desaturation levels of fatty acids) in HFD-fed rats. Furthermore, SCD deficiency mimicked the ability of 6-G to reduce lipid accumulation in HF-induced HepG2 cells, and impaired the improvement in hepatic steatosis brought about by 6-G treatment in HFD supplemented with oleic acid diet-induced SCD1 knockout mice. Taken together, our present study demonstrated that 6-G inhibits DNL by targeting SCD to alleviate fructose diet-induced hepatic steatosis.

Excess dietary sugar and its impact on periodontal inflammation: a narrative review

INTRODUCTION

Sugar is omnipresent in the current food environment and sugar consumption has drastically risen over the past century. Extensive evidence highlights the negative health consequences of consuming excess dietary sugars, leading the World Health Organization (WHO) and the American Heart Association (AHA) to devise guidelines to restrict sugar intake. According to the WHO's Global Oral Health Status Report of 2022, oral diseases and severe periodontitis are a massive public health problem, and dietary sugars are a modifiable risk factor.

METHODS

We conducted a literature review using key databases to summarise the health effects of excessive sugar consumption and their potential role in periodontal inflammation.

RESULTS AND CONCLUSION

Available evidence suggests that excess dietary fructose and sucrose can cause low-grade systemic inflammation; and induce dysbiosis in both gut and the oral microbiota. Also, dietary sugar is potentially addictive and hypercaloric and its overconsumption can lead to obesity, metabolic syndrome, and other risk factors for periodontal inflammation. Hence, an unbalanced diet with excess dietary sugars holds the potential to initiate and aggravate periodontal inflammation. In the modern food environment that enables and facilitates a high-sugar diet, adopting a diverse diet and restricting sugar intake according to WHO and AHA guidelines seem beneficial to systemic and periodontal health. Since clinical evidence is limited, future research should study the effectiveness of dietary interventions that control sugar consumption in preventing and managing the global public health problem of periodontal inflammation.

Diet predisposes to pancreatic cancer through cellular nutrient sensing pathways

Pancreatic cancer is a lethal disease with limited effective treatments. A deeper understanding of its molecular mechanisms is crucial to reduce incidence and mortality. Epidemiological evidence suggests a link between diet and disease risk, though dietary recommendations for at-risk individuals remain debated. Here, we propose that cell-intrinsic nutrient sensing pathways respond to specific diet-derived cues to facilitate oncogenic transformation of pancreatic epithelial cells. This review explores how diet influences pancreatic cancer predisposition through nutrient sensing and downstream consequences for (pre-)cancer cell biology. We also examine experimental evidence connecting specific food intake to pancreatic cancer progression, highlighting nutrient sensing as a promising target for therapeutic development to mitigate disease risk.

Cardiac Hypertrophy in Pregnant Rats, Descendants of Fructose-Fed Mothers, an Effect That Worsens with Fructose Supplementation

The role of fructose consumption in the development of obesity, MetS, and CVD epidemic has been widely documented. Notably, among other effects, fructose consumption has been demonstrated to induce cardiac hypertrophy. Moreover, fructose intake during pregnancy can cause hypertrophy of the maternal heart. Our previous research has demonstrated that maternal fructose intake has detrimental effects on fetuses, which persist into adulthood and are exacerbated upon re-exposure to fructose. Additionally, we found that maternal fructose consumption produces changes in female progeny that alter their own pregnancy. Despite these findings, fructose intake during pregnancy is not currently discouraged. Given that cardiac hypertrophy is a prognostic marker for heart disease and heart failure, this study aimed to determine whether metabolic changes occurring during pregnancy in the female progeny of fructose-fed mothers could provoke a hypertrophic heart. To test this hypothesis, pregnant rats from fructose-fed mothers, with (FF) and without (FC) fructose supplementation, were studied and compared to pregnant control rats (CC). Maternal hearts were analyzed. Although both FF and FC mothers exhibited heart hypertrophy compared to CC rats, cardiac DNA content was more diminished in the hearts of FF dams than in those of FC rats, suggesting a lower number of heart cells. Accordingly, changes associated with cardiac hypertrophy, such as HIF1α activation and hyperosmolality, were observed in both the FC and FF dams. However, FF dams also exhibited higher oxidative stress, lower autophagy, and decreased glutamine protection against hypertrophy than CC dams. In conclusion, maternal fructose intake induces changes in female progeny that alter their own pregnancy, leading to cardiac hypertrophy, which is further exacerbated by subsequent fructose intake.

Interindividual Variability in Postprandial Plasma Fructose Patterns in Adults

High fructose consumption is associated with an increased risk of cardiometabolic disease, and fructose feeding dose-dependently induces markers reflective of poor metabolic health. However, unlike glucose, surprisingly little is known about person-to-person differences in postprandial plasma fructose patterns. Herein, we performed post hoc analyses of two published studies to address this question. In the first cohort, 16 participants' all-day plasma fructose concentration patterns (08:00-23:30) were determined (8 women and 8 men) while consuming mixed meals (breakfast, lunch, and dinner) with a fructose-sweetened beverage at each meal (30% of calories). Individually plotted results demonstrate remarkably disparate fructose patterns with respect to peak concentration and timing. A secondary study confirmed substantial interindividual variability in plasma fructose patterns over 240 min in 16 adults consuming Ensure®, a commercially available mixed macronutrient drink containing a low dose of fructose. The health ramifications of interindividual variations in postprandial fructose metabolism and the underlying physiological mechanisms driving differences in post-meal blood patterns remain to be explored. Future research is warranted to determine if interindividual variability in fructose digestion, metabolism, and postprandial blood concentration patterns is associated with cardiometabolic health phenotypes and disease risk.

Long-term high fructose intake reprograms the circadian transcriptome and disrupts homeostasis in mouse extra-orbital lacrimal glands

This study aims to explore the effects of long-term high fructose intake (LHFI) on the structure, functionality, and physiological homeostasis of mouse extra-orbital lacrimal glands (ELGs), a critical component of ocular health. Our findings reveal significant reprogramming of the circadian transcriptome in ELGs following LHFI, alongside the activation of specific inflammatory pathways, as well as metabolic and neural pathways. Notably, LHFI resulted in increased inflammatory infiltration, enhanced lipid deposition, and reduced nerve fiber density in ELGs compared to controls. Functional assessments indicated a marked reduction in lacrimal secretion following cholinergic stimulation in LHFI-treated mice, suggesting impaired gland function. Overall, our results suggest that LHFI disrupts lacrimal gland homeostasis, potentially leading to dry eye disease by altering its structure and secretory function. These insights underscore the profound impact of dietary choices on ocular health and highlight the need for strategies to mitigate these risks.

Effects of chronic exposure to a high fat diet, nutritive or non-nutritive sweeteners on hypothalamic-pituitary-adrenal (HPA) and -gonadal (HPG) axes of male Sprague-Dawley rats

PURPOSE

Diet-related factors are of great significance in the regulation of hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonad (HPG) axes. In this study, we aimed to investigate the effects of chronic exposure to a high fat diet (HFD), fructose or sucralose on the endocrine functions.

METHODS

Male, Sprague-Dawley rats received a normal chow diet, HFD, 10% fructose or 0.02% sucralose for 10 weeks. Behavioral changes were assessed by open field (OFT) and elevated plus-maze (EPM) tests at week 8. H&E staining was used to observe pathological changes in adrenal cortex, testis and perirenal adipose tissue. Serum hormone concentrations were quantified via enzyme-linked immunosorbent assay (ELISA). The mRNA expression levels of genes along the HPA and HPG axes were determined using real-time PCR.

RESULTS

All types of dietary interventions increased body weight and disturbed metabolic homeostasis, with anxiogenic phenotype in behavioral tests and damage to cell morphology of adrenal cortex and testis being observed. Along the HPA axis, significantly increased corticotropin releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and corticosterone (CORT) concentrations were observed in the HFD or 0.02% sucralose group. For HPG axis, gonadotropin-releasing hormone (GnRH) and estradiol (E2) concentrations were significantly increased in all dietary intervention groups, while decreased concentrations of follicle-stimulating hormone (FSH) and testosterone (T) were also detected. Moreover, transcriptional profiles of genes involved in the synthesis of hormones and corresponding hormone receptors were significantly altered.

CONCLUSION

Long-term consumption of HFD, fructose or sucralose manifested deleterious effects on endocrine system and resulted in the dysregulation of HPA and HPG axes.

Dysbiosis and nutrition in steatotic liver disease: addressing the unrecognized small intestinal bacterial overgrowth (SIBO) challenge

Steatotic liver disease (SLD) is characterized by hepatic fat accumulation, potentially causing major consequences such as liver decompensation. Currently, we lack medications for the treatment of SLD. Therapeutic recommendations for patients include a hypocaloric diet, weight loss, and physical activity. In particular, the Mediterranean diet is frequently recommended. However, this diet might exacerbate intestinal problems in a subset of patients with coexisting small intestinal bacterial overgrowth (SIBO). Previous studies have reported that SIBO is more predominant in patients with fatty liver than in healthy individuals. Both our research and the findings of others have highlighted a challenge related to nutritional therapy in patients with fatty liver who also suffer from SIBO inasmuch as SIBO induces several phenomena (like bloating or abdominal pain) that can adversely affect patients' quality of life and might be exacerbated by the Mediterranean diet. This may lower their adherence to the intervention. As a solution, we suggest introducing additional diagnostics (e.g., breath test) in patients with SLD who complain of SIBO-like symptoms. The next step is to modify their diets temporarily starting with several weeks of "elimination and sanitation." This would involve restricting products rich in fermentable sugars and polyols, while simultaneously treating the bacterial overgrowth. In summary, while the hypocaloric Mediterranean diet is beneficial for patients with fatty liver, those with coexisting SIBO may experience exacerbated symptoms. It is vital to consider additional diagnostics and dietary modifications for this subset of patients to address both liver and intestinal health concurrently.

Partial validation of a six-month high-fat diet and fructose-glucose drink combination as a mouse model of nonalcoholic fatty liver disease

PURPOSE

The need to investigate the pathogenesis and treatment of nonalcoholic fatty liver disease (NAFLD) has led to the development of multiple mouse models. The aim of this study was to validate a fast food diet (FFD) mouse model that is introduced as being close to the human disease.

METHODS

Eight to nine weeks old male and female C57BL/6 J mice were randomly allocated to a FFD group or to a chow diet (CD) group. Every four weeks, mice were weighed, and blood samples were collected for the measurement of glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglycerides (TGs) and total cholesterol. After 25 weeks, mice were sacrificed, and liver tissue was histologically evaluated.

RESULTS

FFD mice gained more weight (p = 0.049) and presented a higher liver-to-body weight ratio (p < 0.001) compared to CD mice. FFD group presented with greater steatosis, hepatocellular ballooning and NAFLD activity score (NAS), whereas lobular inflammation and fibrosis were not significantly different compared to CD. When stratified by sex, NAS was different between FFD and CD groups in both male and female mice. Group by time interaction was significant for weight, ALT and cholesterol, but not for glucose, AST and TGs.

CONCLUSION

FFD mice presented with morphologic and biochemical features of NAFLD and with greater hepatic steatosis, hepatocellular ballooning and NAS, but not lobular inflammation and fibrosis, compared to CD mice. These results only partly validate the FFD mouse model for NAFLD, at least for a 6-month feeding period.

Megalin Knockout Reduces SGLT2 Expression and Sensitizes to Western Diet-induced Kidney Injury

Megalin (Lrp2) is a multiligand receptor that drives endocytic flux in the kidney proximal tubule (PT) and is necessary for the recovery of albumin and other filtered proteins that escape the glomerular filtration barrier. Studies in our lab have shown that knockout (KO) of Lrp2 in opossum PT cells leads to a dramatic reduction in sodium-glucose co-transporter 2 (SGLT2) transcript and protein levels, as well as differential expression of genes involved in mitochondrial and metabolic function. SGLT2 transcript levels are reduced more modestly in Lrp2 KO mice. Here, we investigated the effects of Lrp2 KO on kidney function and health in mice fed regular chow (RC) or a Western-style diet (WD) high in fat and refined sugar. Despite a modest reduction in SGLT2 expression, Lrp2 KO mice on either diet showed increased glucose tolerance compared to control mice. Moreover, Lrp2 KO mice were protected against WD-induced fat gain. Surprisingly, renal function in male Lrp2 KO mice on WD was compromised, and the mice exhibited significant kidney injury compared with control mice on WD. Female Lrp2 KO mice were less susceptible to WD-induced kidney injury than male Lrp2 KO. Together, our findings reveal both positive and negative contributions of megalin expression to metabolic health, and highlight a megalin-mediated sex-dependent response to injury following WD.

Fructose induces hepatic steatosis in adolescent mice linked to the disorders of lipid metabolism, bile acid metabolism, and autophagy

The effects of excessive fructose intake on the development and progression of metabolic disorders have received widespread attention. However, the deleterious effects of fructose on the development of hepatic metabolic disease in adolescents and its potential mechanisms are not fully understood. In this study, we investigated the effects of isocaloric fructose-rich diets on the liver of adolescent mice. The results showed that fructose-rich diets had no effect on the development of obesity in the adolescent mice, but did induce hepatic lipid accumulation. Besides, we found that fructose-rich diets promoted hepatic inflammatory responses and oxidative stress in adolescent mice, which may be associated with activation of the NLRP3 inflammasome and inhibition of the Nrf2 pathway. Furthermore, our results showed that fructose-rich diets caused disturbances in hepatic lipid metabolism and bile acid metabolism, as well as endoplasmic reticulum stress and autophagy dysfunction. Finally, we found that the intestinal barrier function was impaired in the mice fed fructose-rich diets. In conclusion, our study demonstrates that dietary high fructose induces hepatic metabolic disorders in adolescent mice. These findings provide a theoretical foundation for fully understanding the effects of high fructose intake on the development of hepatic metabolic diseases during adolescence.

Common Denominator of MASLD and Some Non-Communicable Diseases

Currently, steatohepatitis has been designated as metabolic dysfunction-associated steatohepatitis (MASLD). MASLD risk factors mainly include metabolic disorders but can also include genetic, epigenetic, and environmental factors. Disease entities such as obesity, diabetes, cardiovascular disease, and MASLD share similar pathomechanisms and risk factors. Moreover, a bidirectional relationship is observed between the occurrence of certain chronic diseases and MASLD. These conditions represent a global public health problem that is responsible for poor quality of life and high mortality. It seems that paying holistic attention to these problems will not only help increase the chances of reducing the incidence of these diseases but also assist in the prevention, treatment, and support of patients.

Assessing the impact of concurrent high-fructose and high-saturated fat diets on pediatric metabolic syndrome: A review

High-saturated fat (HF) or high-fructose (HFr) consumption in children predispose them to metabolic syndrome (MetS). In rodent models of MetS, diets containing individually HF or HFr lead to a variable degree of MetS. Nevertheless, simultaneous intake of HF plus HFr have synergistic effects, worsening MetS outcomes. In children, the effects of HF or HFr intake usually have been addressed individually. Therefore, we have reviewed the outcomes of HF or HFr diets in children, and we compare them with the effects reported in rodents. In humans, HFr intake causes increased lipogenesis, hypertriglyceridemia, obesity and insulin resistance. On the other hand, HF diets promote low grade-inflammation, obesity, insulin resistance. Despite the deleterious effects of simultaneous HF plus HFr intake on MetS development in rodents, there is little information about the combined effects of HF plus HFr intake in children. The aim of this review is to warn about this issue, as individually addressing the effects produced by HF or HFr may underestimate the severity of the outcomes of Western diet intake in the pediatric population. We consider that this is an alarming issue that needs to be assessed, as the simultaneous intake of HF plus HFr is common on fast food menus.

Transcriptomic insights into the lipotoxicity of high-fat high-fructose diet in rat and mouse

Along with the increasing prevalence of obesity worldwide, the deleterious effects of high-calorie diet are gradually recognized through more and more epidemiological studies. However, the concealed and chronic causality whitewashes its unhealthy character. Given an ingenious mechanism orchestrates the metabolic adaptation to high-fat high-fructose (HFF) diet and connive its lipotoxicity, in this study, an experimental rat/mouse model of obesity was induced and a comparative transcriptomic analysis was performed to probe the mystery. Our results demonstrated that HFF diet consumption altered the transcriptomic pattern as well as different high-calorie diet fed rat/mouse manifested distinct hepatic transcriptome. Validation with RT-qPCR and Western blotting confirmed that SREBP1-FASN involved in de novo lipogenesis partly mediated metabolic self-adaption. Moreover, hepatic ACSL1-CPT1A-CPT2 pathway involved in fatty acids β-oxidation, played a key role in the metabolic adaption to HFF. Collectively, our findings enrich the knowledge of the chronic adaptation mechanisms and also shed light on future investigations. Meanwhile, our results also suggest that efforts to restore the fatty acids metabolic fate could be a promising avenue to fight against obesity and associated steatosis and insulin resistance challenged by HFF diet.

Exploring the Role of Phenolic Compounds in Chronic Kidney Disease: A Systematic Review

Chronic kidney disease (CKD) presents a formidable global health concern, affecting one in six adults over 25. This review explores the potential of phenolic compounds in managing CKD and its complications. By examining the existing research, we highlight their diverse biological activities and potential to combat CKD-related issues. We analyze the nutritional benefits, bioavailability, and safety profile of these compounds. While the clinical evidence is promising, preclinical studies offer valuable insights into underlying mechanisms, optimal dosages, and potential side effects. Further research is crucial to validate the therapeutic efficacy of phenolic compounds for CKD. We advocate for continued exploration of their innovative applications in food, pharmaceuticals, and nutraceuticals. This review aims to catalyze the scientific community's efforts to leverage phenolic compounds against CKD-related challenges.

A high-fat diet promotes cancer progression by inducing gut microbiota-mediated leucine production and PMN-MDSC differentiation

A high-fat diet (HFD) is a high-risk factor for the malignant progression of cancers through the disruption of the intestinal microbiota. However, the role of the HFD-related gut microbiota in cancer development remains unclear. This study found that obesity and obesity-related gut microbiota were associated with poor prognosis and advanced clinicopathological status in female patients with breast cancer. To investigate the impact of HFD-associated gut microbiota on cancer progression, we established various models, including HFD feeding, fecal microbiota transplantation, antibiotic feeding, and bacterial gavage, in tumor-bearing mice. HFD-related microbiota promotes cancer progression by generating polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs). Mechanistically, the HFD microbiota released abundant leucine, which activated the mTORC1 signaling pathway in myeloid progenitors for PMN-MDSC differentiation. Clinically, the elevated leucine level in the peripheral blood induced by the HFD microbiota was correlated with abundant tumoral PMN-MDSC infiltration and poor clinical outcomes in female patients with breast cancer. These findings revealed that the "gut-bone marrow-tumor" axis is involved in HFD-mediated cancer progression and opens a broad avenue for anticancer therapeutic strategies by targeting the aberrant metabolism of the gut microbiota.

Effects of Excessive High-fructose Corn Syrup Drink Intake in Middle-aged Mice

BACKGROUND/AIM

The global prevalence of type 2 diabetes (T2D) continues to increase, necessitating the need for understanding the causes of its development. The widespread use of high-fructose corn syrup (HFCS) in drinks and diets is suspected to play a role in metabolic disorders. Although many studies have reported on the effects of excessive HFCS and excessive energy intakes in middle-aged individuals, few have focused on energy restriction. This study aimed to investigate the effects of excessive HFCS drink intake under energy restriction on developing T2D in early middle-aged mice.

MATERIALS AND METHODS

Early middle-aged mice were divided in HFCS and control groups; they were provided either 10% HFCS water or deionized water ad libitum for 12 weeks, respectively. Total energy intake was controlled using a standard rodent diet. Oral glucose tolerance test (OGTT), insulin tolerance test (ITT), tissue weight measurements, serum parameter analyses, and mRNA expression assessments were performed.

RESULTS

No increase in body and adipose tissue weight was observed with excessive HFCS intake under energy restriction. Moreover, serum lipid parameters did not differ from those of controls. However, in the OGTT and ITT, the HFCS group showed higher blood glucose levels than the control group. Moreover, the pancreatic weight and insulin II mRNA expression were reduced.

CONCLUSION

The excessive HFCS drink intake under energy restriction did not induce obesity; however, it induced impaired glucose tolerance, indicating its negative effects on the pancreas in early middle-aged mice. When translated in human physiology, our results show that even if one does not become obese, excessive HFCS may affect the overall metabolic mechanism; these effects may vary depending on age.

Gut microbiota in MAFLD: therapeutic and diagnostic implications

Metabolic dysfunction-associated fatty liver disease (MAFLD), formerly known as nonalcoholic fatty liver disease, is becoming a significant contributor to chronic liver disease globally, surpassing other etiologies, such as viral hepatitis. Prevention and early treatment strategies to curb its growing prevalence are urgently required. Recent evidence suggests that targeting the gut microbiota may help treat and alleviate disease progression in patients with MAFLD. This review aims to explore the complex relationship between MAFLD and the gut microbiota in relation to disease pathogenesis. Additionally, it delves into the therapeutic strategies targeting the gut microbiota, such as diet, exercise, antibiotics, probiotics, synbiotics, glucagon-like peptide-1 receptor agonists, and fecal microbiota transplantation, and discusses novel biomarkers, such as microbiota-derived testing and liquid biopsy, for their diagnostic and staging potential. Overall, the review emphasizes the urgent need for preventive and therapeutic strategies to address the devastating consequences of MAFLD at both individual and societal levels and recognizes that further exploration of the gut microbiota may open avenues for managing MAFLD effectively in the future.

Bile acids mediate fructose-associated liver tumour growth in mice

High fructose diets are associated with an increased risk of liver cancer. Previous studies in mice suggest increased lipogenesis is a key mechanism linking high fructose diets to liver tumour growth. However, these studies administered fructose to mice at supraphysiological levels. The aim of this study was to determine whether liver tumour growth and lipogenesis were altered in mice fed fructose at physiological levels. To test this, we injected male C57BL/6 mice with the liver carcinogen diethylnitrosamine and then fed them diets without fructose or fructose ranging from 10 to 20 % total calories. Results showed mice fed diets with ≥15 % fructose had significantly increased liver tumour numbers (2-4-fold) and total tumour burden (∼7-fold) vs mice fed no-fructose diets. However, fructose-associated tumour burden was not associated with lipogenesis. Conversely, unbiased metabolomic analyses revealed bile acids were elevated in the sera of mice fed a 15 % fructose diet vs mice fed a no-fructose diet. Using a syngeneic ectopic liver tumour model, we show that ursodeoxycholic acid, which decreases systemic bile acids, significantly reduced liver tumour growth in mice fed the 15 % fructose diet but not mice fed a no-fructose diet. These results point to a novel role for systemic bile acids in mediating liver tumour growth associated with a high fructose diet. Overall, our study shows fructose intake at or above normal human consumption (≥15 %) is associated with increased liver tumour numbers and growth and that modulating systemic bile acids inhibits fructose-associated liver tumour growth in mice.

Fructose corn syrup induces inflammatory injury and obesity by altering gut microbiota and gut microbiota-related arachidonic acid metabolism

Excessive fructose corn syrup (FCS) intake brings a series of health problems. The aim of the present study was to explore the mechanism of FCS-induced metabolic disorders from the perspective of gut microbiota. Mice were fed for 16 weeks with normal or 30% FCS drinking water. Compared to the control group, FCS caused significantly higher fat deposition, hepatic steatosis, liver and intestinal inflammatory damages (P<.05). FCS increased the abundance of Muribaculaceae in vivo and in vitro, which was positively correlated with the indices of metabolic disorders (P<.05). In vivo and in vitro data indicated that FCS enhanced the microbial function involved in pentose phosphate pathway and arachidonic acid metabolism, metabolomics further demonstrated that FCS led to an increase in prostaglandins (the catabolites of arachidonic acid) (P<.05). Our study confirmed that FCS can directly promote gut microbiota to synthesize inflammatory factor prostaglandins, which provides new insights and directions for the treatment of FCS-induced metabolic disorders and inflammation.

Association between higher duodenal levels of the fructose carrier glucose transporter-5 and nonalcoholic fatty liver disease and liver fibrosis

BACKGROUND

An increased dietary fructose intake has been shown to exert several detrimental metabolic effects and contribute to the pathogenesis of nonalcoholic fatty liver disease (NAFLD). An augmented intestinal abundance of the fructose carriers glucose transporter-5 (GLUT-5) and glucose transporter-2 (GLUT-2) has been found in subjects with obesity and type 2 diabetes. Herein, we investigated whether elevated intestinal levels of GLUT-5 and GLUT-2, resulting in a higher dietary fructose uptake, are associated with NAFLD and its severity.

METHODS

GLUT-5 and GLUT-2 protein levels were assessed on duodenal mucosa biopsies of 31 subjects divided into 2 groups based on ultrasound-defined NAFLD presence who underwent an upper gastrointestinal endoscopy.

RESULTS

Individuals with NAFLD exhibited increased duodenal GLUT-5 protein levels in comparison to those without NAFLD, independently of demographic and anthropometric confounders. Conversely, no difference in duodenal GLUT-2 abundance was observed amongst the two groups. Univariate correlation analyses showed that GLUT-5 protein levels were positively related with body mass index, waist circumference, fasting and 2 h post-load insulin concentrations, and insulin resistance (IR) degree estimated by homeostatic model assessment of IR (r = 0.44; p = 0.02) and liver IR (r = 0.46; p = 0.03) indexes. Furthermore, a positive relationship was observed between duodenal GLUT-5 abundance and serum uric acid concentrations (r = 0.40; p = 0.05), a product of fructose metabolism implicated in NAFLD progression. Importantly, duodenal levels of GLUT-5 were positively associated with liver fibrosis risk estimated by NAFLD fibrosis score.

CONCLUSION

Increased duodenal GLUT-5 levels are associated with NAFLD and liver fibrosis. Inhibition of intestinal GLUT-5-mediated fructose uptake may represent a strategy for prevention and treatment of NAFLD.

Myricetin May Improve Cardiac Dysfunction Possibly Through Regulating Blood Pressure and Cellular Stress Molecules in High-Fructose-Fed Rats

BACKGROUND

The aim of this study was to examine the effect of myricetin on cardiac dysfunction caused by high fructose intake.

METHODS

Fructose was given to the rats as a 20% solution in drinking water for 15 weeks. Myricetin was administered by oral gavage for the last 6 weeks. Systolic blood pressure was measured by tail-cuff method. The effects of isoprenaline, phenylephrine, and acetylcholine on cardiac contractility and rhythmicity were recorded in the isolated right atrium and left ventricular papillary muscles. In addition to biochemical measurements, the cardiac expressions of cellular stress-related proteins were determined by western blotting.

RESULTS

Myricetin improved systolic blood pressure but did not affect body weight, plasma glucose, and triglyceride levels in fructose-fed rats. The impairment of isoprenaline- and phenylephrine-mediated increases in atrial contraction and sinus rate in fructose-fed rats was restored by myricetin treatment. Isoprenaline, phenylephrine, and acetylcholine-mediated papillary muscle contractions were not changed by fructose or myricetin administration. The expression of the mitochondrial fission marker dynamin-related protein 1 and the mitophagic marker PTEN-induced kinase 1 (PINK1) was enhanced in the fructose-fed rat, and myricetin treatment markedly attenuated PINK1 expression. High-fructose intake augmented phosphorylation of the proinflammatory molecule Nuclear factor kappa B (NF-κB) and the stress-regulated kinase JNK1, but myricetin only reduced NF-κB expression. Moreover, myricetin diminished the elevation in the expression of the pro-apoptotic Bax.

CONCLUSION

Our results imply that myricetin has a protective role in cardiac irregularities induced by a high-fructose diet through reducing systolic blood pressure, improving cardiac adrenergic responses, suppressing PINK1, NF-κB, and Bax expression, and thus reflecting a potential therapeutic value.

Fructose: a modulator of intestinal barrier function and hepatic health?

PURPOSE

Consumption of fructose has repeatedly been discussed to be a key factor in the development of health disturbances such as hypertension, diabetes type 2, and non-alcoholic fatty liver disease. Despite intense research efforts, the question if and how high dietary fructose intake interferes with human health has not yet been fully answered.

RESULTS

Studies suggest that besides its insulin-independent metabolism dietary fructose may also impact intestinal homeostasis and barrier function. Indeed, it has been suggested by the results of human and animal as well as in vitro studies that fructose enriched diets may alter intestinal microbiota composition. Furthermore, studies have also shown that both acute and chronic intake of fructose may lead to an increased formation of nitric oxide and a loss of tight junction proteins in small intestinal tissue. These alterations have been related to an increased translocation of pathogen-associated molecular patterns (PAMPs) like bacterial endotoxin and an induction of dependent signaling cascades in the liver but also other tissues.

CONCLUSION

In the present narrative review, results of studies assessing the effects of fructose on intestinal barrier function and their impact on the development of health disturbances with a particular focus on the liver are summarized and discussed.

Different Effects of High-Fat/High-Sucrose and High-Fructose Diets on Advanced Glycation End-Product Accumulation and on Mitochondrial Involvement in Heart and Skeletal Muscle in Mice

Diets with an elevated content of fat, sucrose, or fructose are recognized models of diet-induced metabolic alterations, since they induce metabolic derangements, oxidative stress, and chronic low-grade inflammation associated with local and systemic accumulation of advanced glycation end-products (AGEs). This study used four-week-old C57BL/6 male mice, randomly assigned to three experimental dietary regimens: standard diet (SD), high-fat high-sucrose diet (HFHS), or high fructose diet (HFr), administered for 12 weeks. Plasma, heart, and tibialis anterior (TA) skeletal muscle were assayed for markers of metabolic conditions, inflammation, presence of AGEs, and mitochondrial involvement. The HFHS diet induced a tissue-specific differential response featuring (1) a remarkable adaptation of the heart to HFHS-induced heavy oxidative stress, demonstrated by an increased presence of AGEs and reduced mitochondrial biogenesis, and efficaciously counteracted by a conspicuous increase in mitochondrial fission and PRXIII expression; (2) the absence of TA adaptation to HFHS, revealed by a heavy reduction in mitochondrial biogenesis, not counteracted by an increase in fission and PRXIII expression. HFr-induced mild oxidative stress elicited tissue-specific responses, featuring (1) a decrease in mitochondrial biogenesis in the heart, likely counteracted by a tendency for increased fission and (2) a mild reduction in mitochondrial biogenesis in TA, likely counteracted by a tendency for increased fusion, showing the adaptability of both tissues to the diet.