High-fat diet alters gut microbiota physiology in mice

Fermented Lignan-Enriched Soy Beverage Ameliorates the Metabolic Effects of a High-Fat Diet on Female Mice

Fermented vegetable beverages have potential beneficial effects on the health associated with the production of bioactive flavonoids and lignans by selected bacterial strains. Here, we studied the effects of a soy beverage and a soy beverage fermented by Bifidobacterium pseudocatenulatum INIA P815, both supplemented with lignan extracts, in a female mouse model on a high-fat diet followed for 16 weeks. The high-fat diet induced an increase in adipose tissue and plasma cholesterol as well as modified the fecal microbiota. Mice groups receiving any of the beverages showed a reduction in the mean area of ovarian fat tissue adipocytes and exhibited bioactive flavonoids and lignans in plasma and tissues, accompanied by a higher antioxidant activity in plasma. The group of mice subjected to the fermented beverage also demonstrated a lower increase in plasma cholesterol levels, an increase in short-chain fatty acid production, and higher levels of daidzein, genistein, enterolignans, and herbacetin in the plasma and organs. Moreover, the fertility of the mice that received the fermented beverage was also enhanced, resulting in a higher percentage of blastocysts per female mouse. Therefore, the consumption of the beverage fermented by B. pseudocatenulatum INIA P815 could be favoring the health of mice by ameliorating, to some extent, the effects of a high-fat diet.

Microbial network inference for longitudinal microbiome studies with LUPINE

BACKGROUND

The microbiome is a complex ecosystem of interdependent taxa that has traditionally been studied through cross-sectional studies. However, longitudinal microbiome studies are becoming increasingly popular. These studies enable researchers to infer taxa associations towards the understanding of coexistence, competition, and collaboration between microbes across time. Traditional metrics for association analysis, such as correlation, are limited due to the data characteristics of microbiome data (sparse, compositional, multivariate). Several network inference methods have been proposed, but have been largely unexplored in a longitudinal setting.

RESULTS

We introduce LUPINE (LongitUdinal modelling with Partial least squares regression for NEtwork inference), a novel approach that leverages on conditional independence and low-dimensional data representation. This method is specifically designed to handle scenarios with small sample sizes and small number of time points. LUPINE is the first method of its kind to infer microbial networks across time, while considering information from all past time points and is thus able to capture dynamic microbial interactions that evolve over time. We validate LUPINE and its variant, LUPINE_single (for single time point analysis) in simulated data and four case studies, where we highlight LUPINE's ability to identify relevant taxa in each study context, across different experimental designs (mouse and human studies, with or without interventions, and short or long time courses). To detect changes in the networks across time and groups or in response to external disturbances, we used different metrics to compare the inferred networks.

CONCLUSIONS

LUPINE is a simple yet innovative network inference methodology that is suitable for, but not limited to, analysing longitudinal microbiome data. The R code and data are publicly available for readers interested in applying these new methods to their studies. Video Abstract.

Avocado (Persea americana Mill.) consumption during pregnancy and lactation induces anxiogenic-like behavior, cerebral oxidative stress and compromises fecal microbiota in rat offspring

This study aimed to evaluate the impact of consumption of avocado oil (AO) and pulp (AP) on anxiety-like behavior, cerebral oxidative stress and alteration of the fecal microbiota in the mother and male Wistar rats offspring treated during gestation and lactation. Anxiety-like behavior was measured through the elevated plus maze (EPM) and open field test (OFT) tests. Cerebral malondialdehyde (MDA) and glutathione (GLUT) levels were measured in mothers and offspring. The fatty acid profile was determined for maternal milk and brain. Data showed a shorter time spent on the open arms of EPM in mothers and offspring for those fed AO and AP (P < 0.001). Moreover, the AO offspring adolescent and adult spent less time in the central area (P < 0.05). Furthermore, offspring adults from the AO moved about less and offspring from the AP ambulated more (P < 0.001). MDA was increased in mothers and decreased in the offspring in AO and AP and GLUT was lower in mothers and higher in adolescent and adult offspring in AP (P < 0.05). Polyunsaturated fatty acids in the brain and breast milk in AO and AP were decreased (P < 0.05). Furthermore, there was an increase in the abundance of intestinal bacteria related to the production of inflammatory metabolites that compromised brain function in offspring treated with avocado. These results suggest that avocado induces anxiogenic-like behavior and increases cerebral oxidative stress in mothers and offspring of rats treated during pregnancy and lactation, negatively altering the fecal microbiota of the offspring. So, we report for the first time how the consumption of avocado oil and pulp interferes with a developing organism when consumed in the early stages of life in rats.

Isomaltodextrin inhibits kidney enlargement induced by a high-protein diet through its metabolism by gut microbiota

To evaluate the effects of the soluble fiber isomaltodextrin in a protein-biased diet, a 21-day protein diet trial was conducted in rats, with 60% of the calories derived from protein. The results revealed that the high-protein diet alone led to a significant increase in kidney weight. In contrast, the consumption of water with 5% isomaltodextrin dissolved in it, along with a high-protein diet, suppressed this weight gain. To elucidate this mechanism, an analysis of serum urea toxins confirmed that the concentrations of phenyl sulfate were significantly higher with high protein, and significantly lower with isomaltodextrin. The impact of a high-protein diet increased phenol in cecal contents, an increase that was mitigated by isomaltodextrin. This suggests that the inhibitory effect of isomaltodextrin on renal hypertrophy was due to the suppression of urea toxin precursor production by the gut microbiota.

The mechanism of perilla oil in regulating lipid metabolism

Emerging science supports the role of lipid metabolism disorders in the occurrence and development of chronic diseases. Dietary intervention has been shown to be an effective strategy for regulating lipid metabolism. Recent studies showed that perilla is rich in various effective ingredients, including fatty acids, flavonoids, and phenolic acids. These ingredients exhibit a myriad of benefits, notably enhancing intestinal health and helping to manage metabolic diseases. Perilla oil stands out as a promising agent for regulating lipid metabolism, underscoring its potential for various health applications. This review introduces the active ingredients in perilla and provides a systematic overview of the mechanism by which perilla oil regulates lipid metabolism to expand its application value. Further research should focus on exploring the dose effect and absorption efficiency of perilla oil in clinical applications.

High-fat diet promotes gestational diabetes mellitus through modulating gut microbiota and bile acid metabolism

Introduction

Gestational diabetes mellitus (GDM) is a condition characterized by glucose intolerance during pregnancy, estimated to affect approximately 20% of the whole pregnancies and is increasing in prevalence globally. However, there is still a big gap in knowledge about the association between gut microbiota associated metabolism alterations and GDM development.

Methods

All the participants accomplished the validated internet-based dietary questionnaire for Chinese and serum, fecal samples were collected. HFD, control diet or colesevelam intervention was fed to GDM mice models or Fxr-/- mice models, with or without antibiotics cocktail treatment. Fecal microbiota transplantation were used for further validation. Gut microbiota and metabolites were detected by metagenomic sequencing and high-performance liquid chromatography-mass spectrometry, respectively. Bile acids of serum, fecal samples from human and mice were analysised. Body weight, average feed intake, blood glucose, insulin levels and oral glucose tolerance test was performed among each groups. Expression levels of Fxr, Shp and Fgf15 mRNA and protein were detected by quantitative reverse transcription polymerase chain reaction and western blot, respectively.

Results

Our data indicated that high fat diet (HFD) was linked with higher prevalence of GDM, and HFD was positively associated with poor prognosis in GDM patients. Moreover, compared with normal diet (ND) group, GDM patients from HFD group performed a loss of gut microbiota diversity and enrichment of Alistipes onderdonkii, Lachnospiraceae bacterium 1_7_58FAA, and Clostridium aspaaragiforme while ruduction of Akkermansiaceae, Paraprevotell xylaniphila, and Prevotella copri. Additionally, HFD aggravated GDM in mice and gut microbiota depletion by antibiotics crippled the effect of excess fat intake. BAs profile altered in HFD GDM patients and mice models. Fecal microbiota transplantation (FMT) further confirmed that gut microbiota contributed to bile acids (BAs) metabolic dysfunction during HFD-associated GDM development. Mechanically, HFD-FMT administration activated Fxr, Shp, and Fgf15 activity, disturbed the glucose metabolism and aggravated insulin resistance but not in HFD-FMT Fxr-/- mice and ND-FMT Fxr-/- mice. Furthermore, colesevelam intervention alleviated HFD-associated GDM development, improved BAs metabolism, suppressed Fxr, Shp, and Fgf15 activity only in WT mice but not in the Fxr-/- HFD + Colesevelam group and Fxr-/- HFD group. HFD induced GDM and contributed to poor prognosis in GDM parturients through inducing gut microbial dysbiosis and metabolic alteration, especially appeared in BAs profile. Moreover, Fxr pathway participated in regulating HFD-associated gut microbiota disordered BAs metabolites and aggravating GDM in mice.

Discussion

Modulating gut microbiota and BAs metabolites could be a potential therapeutic strategy in the prevention and treatment of HFD-associated GDM.

Dietary supplementation with proanthocyanidins and rutin alleviates the symptoms of type 2 diabetes mice and regulates gut microbiota

Background

Obesity and high fasting blood glucose (FBG) resulting from high-fat diets (HFDs) have emerged as significant public health concerns, garnering increasing attention. Recently, gut microbiota has been linked with metabolic diseases such as type 2 diabetes (T2DM), and its mediating role in dietary supplements has been confirmed. Seeking various dietary supplements to lose body weight (BW) and decrease FBG and explaining the underlying mechanism have become the research hotspots in T2DM studies.

Methods

In this study, rutin and proanthocyanidins (PA) were selected as dietary supplements (200 mg/kg × day, oral gavage, 6 weeks) in T2DM mice induced with HFD to assess their efficacy in weight loss, FBG reduction, gut microbiota alterations, and the associated underlying mechanisms.

Results

Our findings indicate that rutin was more effective than PA in relieving inflammation and fat hypertrophy, although both significantly reduced BW and FBG within 2 weeks after the intervention. Analysis of 16S rRNA amplicons revealed substantial alterations in the gut microbial community composition of mice administered with PA and rutin compared to HFD-fed mice. Importantly, several core microbes, particularly a series of probiotics, such as Akkermansia, Lactococcus, Odoribacter, Faecalibaculum, and Roseburia were identified, which were significantly correlated with the changes in BW and FBG.

Conclusion

Overall, our study highlights that rutin and PA can reduce BW, FBG, and inflammation by modulating the gut microbiota composition, providing novel perspectives for managing and treating weight and FBG concerns in obesity and T2DM patients through dietary supplements in clinical treatment.

Green Radish Polysaccharides Ameliorate Hyperlipidemia in High-Fat-Diet-Induced Mice via Short-Chain Fatty Acids Production and Gut Microbiota Regulation

The objective of this study was to examine the hypolipidemic effect and potential mechanism of action of green radish polysaccharide (GRP) in hyperlipidemic mice. We found that in mice fed a high-fat diet, supplementing with GRP reduced body weight and liver index, significantly improved serum lipid levels and markers of liver damage, and mitigated oxidative stress and inflammation. Mechanistically, in these hyperlipidemic mice, the size of fat cells was reduced by GRP, and the abnormal accumulation of lipid droplets was reduced. We also found that GRP regulates the composition of the intestinal microbiota, including the ratio of Firmicutes to Mycobacteria F/B and the levels of Blautia spp., which have been shown to alleviate liver damage and treat hyperlipidemia. Metabolite pathway analysis using the Kyoto Encyclopedia of Genes and Genomes identified the glycolysis/glycolytic metabolism and propionate metabolism pathways as potential targets for GRP in the amelioration of hyperlipidemia.

Overweight Leads to an Increase in Vitamin E Absorption and Status in Mice

SCOPE

This study investigates whether vitamin E (VE) deficiency in subjects with obesity could, at least partly, be due to a defect in VE intestinal absorption.

METHODS AND RESULTS

Mice follow either a high-fat (HF) or a control (CTL) diet for 12 weeks. The study evaluates their VE status, the expression of genes encoding proteins involved in lipid and fat-soluble vitamin intestinal absorption, and VE absorption using a γ-tocopherol-rich emulsion. HF mice have a weight (+23.0%) and an adiposity index (AI, +157.0) superior to CTL mice (p < 0.05). α-Tocopherol concentrations are higher in both plasma (+45.0%) and liver (+116.9%) of HF mice compared to CTL mice (p < 0.05). α-Tocopherol concentration in the adipose tissue of HF mice is higher than that of CTL mice after correction by the AI (+72.4%, p < 0.05). No difference is found in the expression of genes coding for proteins involved in intestinal lipid metabolism in fasting mice. After force-feeding, γ-tocopherol plasma concentration is higher in HF mice compared to CTL mice (+181.5% at 1.5 h after force-feeding, p < 0.05).

CONCLUSION

HF mice display higher status and more efficient absorption of VE than CTL mice. VE absorption is thus likely not impaired in the early stages of obesity.

OM-85 attenuates high-fat diet-induced obesity, insulin resistance, gut dysbiosis and nonalcoholic steatohepatitis in a murine model

BACKGROUND

Obesity is a global epidemic that is tied to a wide range of human disorders. Chronic consumption of a high-fat diet is linked to disruption of the intestinal microbiome, which drives obesity-related pathophysiology. Broncho-Vaxom® (OM-85), a bacterial lysate used for prophylaxis of recurrent respiratory tract infections, has both immunostimulatory and immunomodulatory functions.

METHODS

Male C57Bl/6 mice were maintained on normal control vs. high-fat diets for 8 weeks and treated or untreated with OM-85 or with the probiotic Lactobacillus plantarum, as a positive control. Mice were evaluated for weight gain, glucose tolerance, insulin tolerance, gut microbiome composition and non-alcoholic steatohepatitis (NASH).

RESULTS

High-fat diet mice developed obesity, insulin resistance, NASH and gut dysbiosis with a shift from the Bacteroidetes phylum, such as Bacteroidales order and Muribaculaceae family organisms to Firmicutes groups, such as the Clostridium and Blautia genuses. Treatment with OM-85 led to 1) prevention of obesity, 2) prevention of insulin resistance, 3) attenuation of NASH and 4) attenuation of gut dysbiosis, with decreased levels of the organisms mentioned above and increases in Verrucomicrobiae phylum organisms such as Akkermansia family microbes as well as Muribaculaceae organisms. These shifts in the gut microbiome predict favorable effects on the short chain fatty acid profile in the gut and increased integrity of the intestinal barrier. Pathway analysis showed that OM-85 decreases rates of carbohydrate metabolism, providing an additional mechanism whereby OM-85 prevents obesity.

CONCLUSION

Immune modulators such as OM-85 should be investigated for their potential therapeutic effects on metabolism.

Youth-derived Lactobacillus rhamnosus with prebiotic xylo-oligosaccharide exhibits anti-hyperlipidemic effects as a novel synbiotic

Changes in dietary patterns and living habits have led to an increasing number of individuals with elevated cholesterol levels. Excessive consumption of high-cholesterol foods can disrupt the body's lipid metabolism. Numerous studies have firmly established the cholesterol-lowering effects of probiotics and prebiotics, with evidence showing that the synergistic use of synbiotics is functionally more potent than using probiotics or prebiotics alone. Currently, the screening strategy involves screening prebiotics for synbiotic development with probiotics as the core. However, in comparison to probiotics, there are fewer types of prebiotics available, leading to limited resources. Consequently, the combinations of synbiotics obtained are restricted, and probiotics and prebiotics are only relatively suitable. Therefore, in this study, a novel synbiotic screening strategy with prebiotics as the core was developed. The synbiotic combination of Lactobacillus rhamnosus S_82 and xylo-oligosaccharides was screened from the intestinal tract of young people through five generations of xylo-oligosaccharides. Subsequently, the cholesterol-lowering ability of the medium was simulated, and the two carbon sources of glucose and xylo-oligosaccharides were screened out. The results showed that synbiotics may participate in cholesterol-lowering regulation by down-regulating the expression of NPC1L1 gene, down-regulating ACAT2 and increasing the expression of ABCG8 gene in vitro through cell adsorption and cell absorption in vitro, and regulating the intestinal microbiota. Synbiotics hold promise as potential candidates for the prevention of hypercholesterolemia in humans and animals, and this study providing a theoretical foundation for the development of new synbiotic products.

Time-resolved multi-omics reveals diverse metabolic strategies of Salmonella during diet-induced inflammation

With a rise in antibiotic resistance and chronic infection, the metabolic response of Salmonella enterica serovar Typhimurium to various dietary conditions over time remains an understudied avenue for novel, targeted therapeutics. Elucidating how enteric pathogens respond to dietary variation not only helps us decipher the metabolic strategies leveraged for expansion but also assists in proposing targets for therapeutic interventions. In this study, we use a multi-omics approach to identify the metabolic response of Salmonella enterica serovar Typhimurium in mice on both a fibrous diet and high-fat diet over time. When comparing Salmonella gene expression between diets, we found a preferential use of respiratory electron acceptors consistent with increased inflammation in high-fat diet mice. Looking at the high-fat diet over the course of infection, we noticed heterogeneity in samples based on Salmonella ribosomal activity, which is separated into three infection phases: early, peak, and late. We identified key respiratory, carbon, and pathogenesis gene expressions descriptive of each phase. Surprisingly, we identified genes associated with host cell entry expressed throughout infection, suggesting subpopulations of Salmonella or stress-induced dysregulation. Collectively, these results highlight not only the sensitivity of Salmonella to its environment but also identify phase-specific genes that may be used as therapeutic targets to reduce infection.IMPORTANCEIdentifying novel therapeutic strategies for Salmonella infection that occur in relevant diets and over time is needed with the rise of antibiotic resistance and global shifts toward Western diets that are high in fat and low in fiber. Mice on a high-fat diet are more inflamed compared to those on a fibrous diet, creating an environment that results in more favorable energy generation for Salmonella. We observed differential gene expression across infection phases in mice over time on a high-fat diet. Together, these findings reveal the metabolic tuning of Salmonella to dietary and temporal perturbations. Research like this, which explores the dimensions of pathogen metabolic plasticity, can pave the way for rationally designed strategies to control disease.

Probing the alterations in mice cecal content due to high-fat diet

The global prevalence of obesity more than doubled between 1990 and 2022. By 2022, 2.5 billion adults aged 18 and older were overweight, with over 890 million of them living with obesity. The urgent need for understanding the impact of high-fat diet, together with the demanding of analytical methods with low energy/chemicals consumption, can be fulfilled by rapid, high-throughput spectroscopic techniques. To understand the impact of high-fat diet on the metabolic signatures of mouse cecal contents, we characterized metabolite variations in two diet-groups (standard vs high-fat diet) using FTIR spectroscopy and multivariate analysis. Their cecal content showed distinct spectral features corresponding to high- and low-molecular-weight metabolites. Further quantification of 13 low-molecular-weight metabolites using liquid chromatography showed significant reduction in the production of short chain fatty acids and amino acids associated with high-fat diet samples. These findings demonstrated the potential of spectroscopy to follow changes in gut metabolites.

A Dual Therapeutic Approach to Diabetes Mellitus via Bioactive Phytochemicals Found in a Poly Herbal Extract by Restoration of Favorable Gut Flora and Related Short-Chain Fatty Acids

Diabetes mellitus (DM), a metabolic and endocrine condition, poses a serious threat to human health and longevity. The emerging role of gut microbiome associated with bioactive compounds has recently created a new hope for DM treatment. UHPLC-HRMS methods were used to identify these compounds in a poly herbal ethanolic extract (PHE). The effects of PHE on body weight (BW), fasting blood glucose (FBG) level, gut microbiota, fecal short-chain fatty acids (SCFAs) production, and the correlation between DM-related indices and gut microbes, in rats were investigated. Chebulic acid (0.368%), gallic acid (0.469%), andrographolide (1.304%), berberine (6.442%), and numerous polysaccharides were the most representative constituents in PHE. A more significant BW gain and a reduction in FBG level towards normal of PHE 600 mg/kg treated rats group were resulted at the end of 28th days of the study. Moreover, the composition of the gut microbiota corroborated the study's hypothesis, as evidenced by an increased ratio of Bacteroidetes to Firmicutes and some beneficial microbial species, including Prevotella copri and Lactobacillus hamster. The relative abundance of Bifidobacterium pseudolongum, Ruminococcus bromii, and Blautia producta was found to decline in PHE treatment groups as compared to diabetic group. The abundance of beneficial bacteria in PHE 600 mg/kg treatment group was concurrently associated with increased SCFAs concentrations of acetate and propionate (7.26 nmol/g and 4.13 nmol/g). The findings of this study suggest a promising approach to prevent DM by demonstrating that these naturally occurring compounds decreased FBG levels by increasing SCFAs content and SCFAs producing gut microbiota.

Obesity intensifies sex-specific interferon signaling to selectively worsen central nervous system autoimmunity in females

Obesity has been implicated in the rise of autoimmunity in women. We report that obesity induces a serum protein signature that is associated with T helper 1 (Th1), interleukin (IL)-17, and multiple sclerosis (MS) signaling pathways selectively in human females. Females, but not male mice, subjected to diet-induced overweightness/obesity (DIO) exhibited upregulated Th1/IL-17 inflammation in the central nervous system during experimental autoimmune encephalomyelitis, a model of MS. This was associated with worsened disability and a heightened expansion of myelin-specific Th1 cells in the peripheral lymphoid organs. Moreover, at steady state, DIO increased serum levels of interferon (IFN)-α and potentiated STAT1 expression and IFN-γ production by naive CD4+ T cells uniquely in female mice. This T cell phenotype was driven by increased adiposity and was prevented by the removal of ovaries or knockdown of the type I IFN receptor in T cells. Our findings offer a mechanistic explanation of how obesity enhances autoimmunity.

Disruption of the intestinal clock drives dysbiosis and impaired barrier function in colorectal cancer

Diet is a robust entrainment cue that regulates diurnal rhythms of the gut microbiome. We and others have shown that disruption of the circadian clock drives the progression of colorectal cancer (CRC). While certain bacterial species have been suggested to play driver roles in CRC, it is unknown whether the intestinal clock impinges on the microbiome to accelerate CRC pathogenesis. To address this, genetic disruption of the circadian clock, in an Apc-driven mouse model of CRC, was used to define the impact on the gut microbiome. When clock disruption is combined with CRC, metagenomic sequencing identified dysregulation of many bacterial genera including Bacteroides, Helicobacter, and Megasphaera. We identify functional changes to microbial pathways including dysregulated nucleic acid, amino acid, and carbohydrate metabolism, as well as disruption of intestinal barrier function. Our findings suggest that clock disruption impinges on microbiota composition and intestinal permeability that may contribute to CRC pathogenesis.

Investigating the Effect of Bacilli and Lactic Acid Bacteria on Water Quality, Growth, Survival, Immune Response, and Intestinal Microbiota of Cultured Litopenaeus vannamei

Shrimp is one of the most important aquaculture industries. Therefore, we determined the effect of nitrifying-probiotic bacteria on water quality, growth, survival, immune response, and intestinal microbiota of Litopenaeus vannamei cultured without water exchange. In vitro, only Bacillus licheniformis used total ammonia nitrogen (TAN), nitrites, and nitrates since nitrogen bubbles were produced. TAN decreased significantly in the treatments with B. licheniformis and Pediococcus pentosaceus and Leuconostoc mesenteroides, but no differences were observed in nitrites. Nitrates were significantly higher in the treatments with bacteria. The final weight was higher only with bacilli and bacilli and LAB treatments. The survival of shrimp in the bacterial treatments increased significantly, and superoxide anion increased significantly only in lactic acid bacteria (LAB) treatment. The activity of phenoloxidase decreased significantly in the treatments with bacteria compared to the control. Shrimp treated with bacilli in the water showed lower species richness. The gut bacterial community after treatments was significantly different from that of the control. Linoleic acid metabolism was positively correlated with final weight and superoxide anion, whereas quorum sensing was correlated with survival. Thus, bacilli and LAB in the water of hyperintensive culture systems act as heterotrophic nitrifers, modulate the intestinal microbiota and immune response, and improve the growth and survival of shrimp. This is the first report on P. pentosaceus and L. mesenteroides identified as nitrifying bacteria.

Fecal microbiota transplantation ameliorates high-fat diet-induced memory impairment in mice

Gut dysbiosis is linked to metabolic and neurodegenerative diseases and comprises a plausible link between high-fat diet (HFD) and brain dysfunction. Here we show that gut microbiota modulation by either antibiotic treatment for 5 weeks or a brief 3-day fecal microbiota transplantation (FMT) regimen from low-fat (control) diet-fed mice decreased weight gain, adipose tissue hypertrophy, and glucose intolerance induced by HFD in C57BL/6 male mice. Notably, gut microbiota modulation by FMT completely reversed impaired recognition memory induced by HFD, whereas modulation by antibiotics had less pronounced effect. Improvement in recognition memory by FMT was accompanied by decreased HFD-induced astrogliosis in the hippocampal cornu ammonis region. Gut microbiome composition analysis indicated that HFD diminished microbiota diversity compared to control diet, whereas FMT partially restored the phyla diversity. Our findings reinforce the role of the gut microbiota on HFD-induced cognitive impairment and suggest that modulating the gut microbiota may be an effective strategy to prevent metabolic and cognitive dysfunction associated with unfavorable dietary patterns.

Long-Term Exposure to Polystyrene Microspheres and High-Fat Diet-Induced Obesity in Mice: Evaluating a Role for Microbiota Dysbiosis

BACKGROUND

Microplastics (MPs) have become a global environmental problem, emerging as contaminants with potentially alarming consequences. However, long-term exposure to polystyrene microspheres (PS-MS) and its effects on diet-induced obesity are not yet fully understood.

OBJECTIVES

We aimed to investigate the effect of PS-MS exposure on high-fat diet (HFD)-induced obesity and underlying mechanisms.

METHODS

In the present study, C57BL/6J mice were fed a normal diet (ND) or a HFD in the absence or presence of PS-MS via oral administration for 8 wk. Antibiotic depletion of the microbiota and fecal microbiota transplantation (FMT) were performed to assess the influence of PS-MS on intestinal microbial ecology. We performed 16S rRNA sequencing to dissect microbial discrepancies and investigated the dysbiosis-associated intestinal integrity and inflammation in serum.

RESULTS

Compared with HFD mice, mice fed the HFD with PS-MS exhibited higher body weight, liver weight, metabolic dysfunction-associated steatotic liver disease (MASLD) activity scores, and mass of white adipose tissue, as well as higher blood glucose and serum lipid concentrations. Furthermore, 16S rRNA sequencing of the fecal microbiota revealed that mice fed the HFD with PS-MS had greater α -diversity and greater relative abundances of Lachnospiraceae, Oscillospiraceae, Bacteroidaceae, Akkermansiaceae, Marinifilaceae, Deferribacteres, and Desulfovibrio, but lower relative abundances of Atopobiaceae, Bifidobacterium, and Parabacteroides. Mice fed the HFD with PS-MS exhibited lower expression of MUC2 mucin and higher levels of lipopolysaccharide and inflammatory cytokines [tumor necrosis factor-α (TNF-α ), interleukin-6 (IL-6), IL-1β , and IL-17A] in serum. Correlation analyses revealed that differences in the microbial flora of mice exposed to PS-MS were associated with obesity. Interestingly, microbiota-depleted mice did not show the same PS-MS-associated differences in Muc2 and Tjp1 expression in the distal colon, expression of inflammatory cytokines in serum, or obesity outcomes between HFD and HFD + PS-MS. Importantly, transplantation of feces from HFD + PS-MS mice to microbiota-depleted HFD-fed mice resulted in a lower expression of mucus proteins, higher expression of inflammatory cytokines, and obesity outcomes, similar to the findings in HFD + PS-MS mice.

CONCLUSIONS

Our findings provide a new gut microbiota-driven mechanism for PS-MS-induced obesity in HFD-fed mice, suggesting the need to reevaluate the adverse health effects of MPs commonly found in daily life, particularly in susceptible populations. https://doi.org/10.1289/EHP13913.

Indole-3-aldehyde Alleviates High-Fat Diet-Induced Gut Barrier Disruption by Increasing Intestinal Stem Cell Expansion

High-fat diet (HFD) feeding is known to cause intestinal barrier disruption, thereby triggering severe intestinal inflammatory disease. Indole-3-aldehyde (IAld) has emerged as a potential candidate for mitigating inflammatory responses and maintaining intestinal homeostasis. However, the role of IAld in the HFD-related intestinal disruption remains unclear. In this study, 48 7 week-old male C57BL/6J mice were assigned to four groups: the normal chow diet (NCD) group received a NCD; the HFD group was fed an HFD; the HFD + IAld200 group was supplemented with 200 mg/kg IAld in the HFD; and the HFD + IAld600 group was supplemented with 600 mg/kg IAld in the HFD. The results showed that dietary IAld supplementation ameliorated fat accumulation and metabolic disorders, which are associated with reduced intestinal permeability. This reduction potentially led to decreased systemic inflammation and enhanced intestinal barrier function in HFD-fed mice. Furthermore, we found that IAld promoted intestinal stem cell (ISC) proliferation by activating aryl hydrocarbon receptors (AHRs) in vivo and ex vivo. These findings suggest that IAld restores the HFD-induced intestinal barrier disruption by promoting AHR-mediated ISC proliferation.

Hair Growth Promoting Effects of Solubilized Sturgeon Oil and Its Correlation with the Gut Microbiome

Androgenetic alopecia is a common disease that occurs in both men and women. Several approved medications have been used to treat this condition, but they are associated with certain side effects. Therefore, use of extracts derived from natural products, such as Siberian sturgeon (Acipenser baerii), and the regulation of the gut microbiota have become important topics of research. Sturgeon is known for its high nutritional value and anti-inflammatory properties; however, its effects on androgenetic alopecia and gut microbiota remain uncharacterized. Here, we aimed to investigate whether solubilized sturgeon oil (SSO) promotes hair growth and regulates the gut microbiome. C57BL/6 mice were divided into four groups. Three groups received topical applications of distilled water, SSO, or minoxidil, and one group was orally administered SSO. Each treatment was administered over 4 weeks. Histopathological analysis revealed a significant increase in follicle number (p < 0.001) and follicle diameter (p < 0.05). Immunohistochemical analysis revealed upregulation of β-catenin and ERK-1, markers involved in hair growth-promoting pathways. Furthermore, microbiome analysis revealed that the reduced gut microbiota was negatively correlated with these markers. Our findings indicate that oral administration of SSO promotes hair growth and regulates the abundance of hair growth-promoting gut microbiota.

Effect of High Dietary Iron on Fat Deposition and Gut Microbiota in Chickens

To meet the demand of consumers for chicken products, poultry breeders have made improvements to chickens. However, this has led to a new problem in the modern poultry industry, namely excessive fat deposition. This study aims to understand the effects of dietary iron supplementation on fat deposition and gut microbiota in chickens. In this study, we investigated the effects of iron on the growth performance, fat deposition, and gut microbiota of silky fowl black-bone chickens. A total of 75 7-week-old silky fowl black-bone chickens were randomly divided into three groups (five replicates per group, five chickens per replicate) and fed them for 28 days using a growing diet (control group), a growing diet + 10% tallow (high-fat diet group, HFD group), and a growing diet + 10% tallow + 500 mg/kg iron (HFDFe500 group), respectively. We detected the effects of iron on the growth performance, fat deposition, and gut microbiota of silky fowl black-bone chickens using the growth performance index test, oil red O staining, and HE staining, and found that the high-fat diet significantly increased liver and serum fat deposition and liver injury, while the addition of iron to the diet could reduce the fat deposition caused by the high-fat diet and alleviate liver injury. In addition, 16S rDNA sequencing was used to compare the relative abundance of gut microbiota in the cecal contents in different feeding groups. The results showed that the high-fat diet could induce gut microbiota imbalance in chickens, while the high-iron diet reversed the gut microbiota imbalance. PICRUSt functional prediction analysis showed that dietary iron supplementation affected amino acid metabolism, energy metabolism, cofactors, and vitamin metabolism pathways. In addition, correlation analysis showed that TG was significantly associated with Firmicutes and Actinobacteriota (p < 0.05). Overall, these results revealed high dietary iron (500 mg/kg) could reduce fat deposition and affect the gut microbiota of silky fowl black-bone chickens, suggesting that iron may regulate fat deposition by influencing the gut microbiota of chickens and provides a potential avenue that prevents excessive fat deposition in chickens by adding iron to the diet.

Comparative analysis of energy homeostasis regulation at different altitudes in Hengduan Mountain of red-backed vole, Eothenomys miletus, during high-fat diet acclimation: examining gut microbial and physiological interactions

The study aimed to explore the similarities and differences in gut microorganisms and their functions in regulating body mass in Eothenomys miletus across different altitudes in the Hengduan Mountains when exposed to a high-fat diet. Eothenomys miletus specimens were gathered from Dali (DL) and Xianggelila (XGLL) in Yunnan Province, China, and categorized into control, high-fat (1 week of high-fat diet), and re-feeding groups (1 week of high-fat diet followed by 2 weeks of standard food). The analysis utilized 16S rRNA sequencing to assess the diversity and structure of intestinal microbial communities in E. miletus. The investigation focused on the impact of high-fat diet consumption and different altitudes on gut microbial diversity, structure, and physiological markers. Results revealed that a high-fat diet influenced the beta diversity of gut microorganisms in E. miletus, leading to variations in microbial community structure between the two regions with different altitudes. High-fat food significantly affected body mass, white adipose tissue mass, triglycerides, and leptin levels, but not food intake. Specific intestinal microorganisms were observed in the high-fat groups, aiding in food digestion and being enriched in particular flora. In particular, microbial genera like Lactobacillus and Hylemonella were enriched in the high-fat group of DL. The enriched microbiota in the control group was associated with plant polysaccharide and cellulose decomposition. Following a high-fat diet, gut microbiota adapted to support lipid metabolism and energy supply, while upon re-feeding, the focus shifted back to cellulose digestion. These findings suggested that alterations in gut microbial composition, alongside physiological markers, play a vital role in adaptation of E. miletus to the diverse habitats of the Hengduan Mountains at varying altitudes.

Effects of dietary metabolizable energy level on hepatic lipid metabolism and cecal microbiota in aged laying hens

Lipid metabolic capacity, feed utilization, and the diversity of gut microbiota are reduced in the late laying stage for laying hens. This experiment aimed to investigate the effects of different levels of dietary metabolizable energy (ME) on hepatic lipid metabolism and cecal microbiota in late laying hens. The 216 Peking Pink laying hens (57-wk-old) were randomly assigned to experimental diets of 11.56 (HM = high ME), 11.14 (MM = medium ME), or 10.72 (LM = low ME) MJ of ME/kg, with each dietary treatment containing 6 replicates per group and 12 chickens per replicate. The HM group showed higher triglyceride (TG), total cholesterol (T-CHO), and low-density lipoprotein cholesterol (LDL-C) concentrations in the liver compared with the LM group; second, the HM group showed higher TG concentration and the LM group showed lower T-CHO concentration compared with MM group; finally, the HM group showed a lower hepatic lipase (HL) activity compared with the MM and LM groups (P < 0.05). There was a significant difference in the microbial community structure of the cecum between the HM and MM groups (P < 0.05). The decrease of dietary ME level resulted in a gradual decrease relative abundance of Proteobacteria. At the genus level, beneficial bacteria were significantly enriched in the LM group compared to the MM group, including Faecalibacterium, Lactobacillus, and Bifidobacterium, (linear discriminant analysis [LDA] >2, P <0.05). In addition, at the species level, Lactobacillus crispatus, Parabacteroides gordonii, Blautia caecimuris, and Lactobacillus johnsonii were significantly enriched in the LM group (LDA>2, P < 0.05). The HM group had a higher abundance of Sutterella spp. compared to the LM group (LDA>2, P <0.05). In conclusion, this research suggests that the reduction in dietary energy level did not adversely affect glycolipid metabolism or low dietary ME (10.72 MJ/kg). The findings can be helpful for maintaining intestinal homeostasis and increasing benefit for gut microbiota in late laying hens.

High-fat diet during early life reshapes the gut microbiome and is associated with the disrupted mammary microenvironment in later life in mice

The influence of gut microbiota on gut health is well-documented, but it remains obscure for extraintestinal diseases such as breast cancer. Moreover, it is entirely unknown how gut dysbiosis during early life contributes to breast tumorigenesis later in life. In this study, we hypothesized that a high-fat diet during early life leads to alterations in the gut microbiome and is associated with disruptions in the mammary microenvironment. Female C57BL/6 mice were fed a low-fat diet (10% kcal fat) or a high-fat diet (HF, 60% kcal fat) for 8 weeks from the age of 4 to 12 weeks, which is equivalent to human childhood and adolescence. Twelve mice were sacrificed immediately after the 8-week feeding, the remainder were euthanized after switching to a normal lifecycle-supporting diet for an additional 12 weeks; the gut microbiome was then sequenced. The 8-week HF diet feeding altered the beta-diversity (Bray & Jaccard P < .01), and the difference remained significant after switching the diet (Bray & Jaccard P < .05). Immediately after HF feeding, a greater number of microbial taxa (>50) were altered, and about half of the taxa (25) remained significantly changed after switching the diet. The abundance of Alistipes, Bilophila, and Rikenellaceae stood out as significantly associated with multiple metabolic and inflammatory biomarkers in mammary tissue, including aromatase, Ccl2, and Cox2. In conclusion, an 8-week early-life HF feeding reshaped the gut microbiome, which connected with disrupted mammary microenvironments.

The intestinal microbiota and metabolic profiles of Strauchbufo raddei underwent adaptive changes during hibernation

The intestinal microbiota help regulate hibernation in vertebrates. However, it needs to be established how hibernation modulates the gut microbiome and intestinal metabolism. In the present study, we used an artificial hibernation model to examine the responses of the gut microbiota of the Strauchbufo raddei to the environmental changes associated with this behavior. Hibernation significantly lowered the diversity of the microbiota and altered the microbial community of the gut. Proteobacteria, Firmicutes, and Bacteroidota were the major bacterial phyla in the intestines of S. raddei. However, Firmicutes and Proteobacteria predominated in the gut of active and hibernating S. raddei, respectively. Certain bacterial genera such as Pseudomonas, Vibrio, Ralstonia, and Rhodococcus could serve as biomarkers distinguishing hibernating and non-hibernating S. raddei. The gut microbiota was more resistant to environmental stress in hibernating than active S. raddei. Moreover, metabolomics revealed that metabolites implicated in fatty acid biosynthesis were highly upregulated in the intestines of hibernating S. raddei. The metabolites that were enriched during hibernation enabled S. raddei to adapt to the low temperatures and the lack of exogenous food that are characteristic of hibernation. A correlation analysis of the intestinal microbiota and their metabolites revealed that the gut microbiota might participate in the metabolic regulation of hibernating S. raddei. The present study clarified the modifications that occur in the intestinal bacteria and their symbiotic relationship with their host during hibernation. These findings are indicative of the adaptive changes in the metabolism of amphibians under different environmental conditions.

Gut Dysbiosis Shaped by Cocoa Butter-Based Sucrose-Free HFD Leads to Steatohepatitis, and Insulin Resistance in Mice

BACKGROUND

High-fat diets cause gut dysbiosis and promote triglyceride accumulation, obesity, gut permeability changes, inflammation, and insulin resistance. Both cocoa butter and fish oil are considered to be a part of healthy diets. However, their differential effects on gut microbiome perturbations in mice fed high concentrations of these fats, in the absence of sucrose, remains to be elucidated. The aim of the study was to test whether the sucrose-free cocoa butter-based high-fat diet (C-HFD) feeding in mice leads to gut dysbiosis that associates with a pathologic phenotype marked by hepatic steatosis, low-grade inflammation, perturbed glucose homeostasis, and insulin resistance, compared with control mice fed the fish oil based high-fat diet (F-HFD).

RESULTS

C57BL/6 mice (5-6 mice/group) were fed two types of high fat diets (C-HFD and F-HFD) for 24 weeks. No significant difference was found in the liver weight or total body weight between the two groups. The 16S rRNA sequencing of gut bacterial samples displayed gut dysbiosis in C-HFD group, with differentially-altered microbial diversity or relative abundances. Bacteroidetes, Firmicutes, and Proteobacteria were highly abundant in C-HFD group, while the Verrucomicrobia, Saccharibacteria (TM7), Actinobacteria, and Tenericutes were more abundant in F-HFD group. Other taxa in C-HFD group included the Bacteroides, Odoribacter, Sutterella, Firmicutes bacterium (AF12), Anaeroplasma, Roseburia, and Parabacteroides distasonis. An increased Firmicutes/Bacteroidetes (F/B) ratio in C-HFD group, compared with F-HFD group, indicated the gut dysbiosis. These gut bacterial changes in C-HFD group had predicted associations with fatty liver disease and with lipogenic, inflammatory, glucose metabolic, and insulin signaling pathways. Consistent with its microbiome shift, the C-HFD group showed hepatic inflammation and steatosis, high fasting blood glucose, insulin resistance, increased hepatic de novo lipogenesis (Acetyl CoA carboxylases 1 (Acaca), Fatty acid synthase (Fasn), Stearoyl-CoA desaturase-1 (Scd1), Elongation of long-chain fatty acids family member 6 (Elovl6), Peroxisome proliferator-activated receptor-gamma (Pparg) and cholesterol synthesis (β-(hydroxy β-methylglutaryl-CoA reductase (Hmgcr). Non-significant differences were observed regarding fatty acid uptake (Cluster of differentiation 36 (CD36), Fatty acid binding protein-1 (Fabp1) and efflux (ATP-binding cassette G1 (Abcg1), Microsomal TG transfer protein (Mttp) in C-HFD group, compared with F-HFD group. The C-HFD group also displayed increased gene expression of inflammatory markers including Tumor necrosis factor alpha (Tnfa), C-C motif chemokine ligand 2 (Ccl2), and Interleukin-12 (Il12), as well as a tendency for liver fibrosis.

CONCLUSION

These findings suggest that the sucrose-free C-HFD feeding in mice induces gut dysbiosis which associates with liver inflammation, steatosis, glucose intolerance and insulin resistance.

Supplementation of a High-Fat Diet with Pentadecylresorcinol Increases the Representation of Akkermansia muciniphila in the Mouse Small and Large Intestines and May Protect against Complications Caused by Imbalanced Nutrition

Imbalanced nutrition, such as a high-fat/high-carbohydrate diet, is associated with negative effects on human health. The composition and metabolic activity of the human gut microbiota are closely related to the type of diet and have been shown to change significantly in response to changes in food content and food supplement administration. Alkylresorcinols (ARs) are lipophilic molecules that have been found to improve lipid metabolism and glycemic control and decrease systemic inflammation. Furthermore, alkylresorcinol intake is associated with changes in intestinal microbiota metabolic activity. However, the exact mechanism through which alkylresorcinols modulate microbiota activity and host metabolism has not been determined. In this study, alterations in the small intestinal microbiota (SIM) and the large intestinal microbiota (LIM) were investigated in mice fed a high-fat diet with or without pentadecylresorcinol (C15) supplementation. High-throughput sequencing was applied for jejunal and colonic microbiota analysis. The results revealed that C15 supplementation in combination with a high-fat diet could decrease blood glucose levels. High-throughput sequencing analysis indicated that C15 intake significantly increased (p < 0.0001) the abundance of the probiotic bacteria Akkermansia muciniphila and Bifidobacterium pseudolongum in both the small and large intestines and increased the alpha diversity of LIM (p < 0.05), but not SIM. The preliminary results suggested that one of the mechanisms of the protective effects of alkylresorcinol on a high-fat diet is the modulation of the content of SIM and LIM and metabolic activity to increase the probiotic bacteria that alleviate unhealthy metabolic changes in the host.

Sex-dependent effects of carbohydrate source and quantity on caspase-1 activity in the mouse central nervous system

BACKGROUND

Mounting evidence links glucose intolerance and diabetes as aspects of metabolic dysregulation that are associated with an increased risk of developing dementia. Inflammation and inflammasome activation have emerged as a potential link between these disparate pathologies. As diet is a key factor in both the development of metabolic disorders and inflammation, we hypothesize that long term changes in dietary factors can influence nervous system function by regulating inflammasome activity and that this phenotype would be sex-dependent, as sex hormones are known to regulate metabolism and immune processes.

METHODS

5-week-old male and female transgenic mice expressing a caspase-1 bioluminescent reporter underwent cranial window surgeries and were fed control (65% complex carbohydrates, 15% fat), high glycemic index (65% carbohydrates from sucrose, 15% fat), or ketogenic (1% complex carbohydrates, 79% fat) diet from 6 to 26 weeks of age. Glucose regulation was assessed with a glucose tolerance test following a 4-h morning fast. Bioluminescence in the brain was quantified using IVIS in vivo imaging. Blood cytokine levels were measured using cytokine bead array. 16S ribosomal RNA gene amplicon sequencing of mouse feces was performed to assess alterations in the gut microbiome. Behavior associated with these dietary changes was also evaluated.

RESULTS

The ketogenic diet caused weight gain and glucose intolerance in both male and female mice. In male mice, the high glycemic diet led to increased caspase-1 biosensor activation over the course of the study, while in females the ketogenic diet drove an increase in biosensor activation compared to their respective controls. These changes correlated with an increase in inflammatory cytokines present in the serum of test mice and the emergence of anxiety-like behavior. The microbiome composition differed significantly between diets; however no significant link between diet, glucose tolerance, or caspase-1 signal was established.

CONCLUSIONS

Our findings suggest that diet composition, specifically the source and quantity of carbohydrates, has sex-specific effects on inflammasome activation in the central nervous system and behavior. This phenotype manifested as increased anxiety in male mice, and future studies are needed to determine if this phenotype is linked to alterations in microbiome composition.

Transfer of modified gut viromes improves symptoms associated with metabolic syndrome in obese male mice

Metabolic syndrome encompasses amongst other conditions like obesity and type-2 diabetes and is associated with gut microbiome (GM) dysbiosis. Fecal microbiota transplantation (FMT) has been explored to treat metabolic syndrome by restoring the GM; however, concerns on accidentally transferring pathogenic microbes remain. As a safer alternative, fecal virome transplantation (FVT, sterile-filtrated feces) has the advantage over FMT in that mainly bacteriophages are transferred. FVT from lean male donors have shown promise in alleviating the metabolic effects of high-fat diet in a preclinical mouse study. However, FVT still carries the risk of eukaryotic viral infections. To address this, recently developed methods are applied for removing or inactivating eukaryotic viruses in the viral component of FVT. Modified FVTs are compared with unmodified FVT and saline in a diet-induced obesity model on male C57BL/6 N mice. Contrasted with obese control, mice administered a modified FVT (nearly depleted for eukaryotic viruses) exhibits enhanced blood glucose clearance but not weight loss. The unmodified FVT improves liver pathology and reduces the proportions of immune cells in the adipose tissue with a non-uniform response. GM analysis suggests that bacteriophage-mediated GM modulation influences outcomes. Optimizing these approaches could lead to the development of safe bacteriophage-based therapies targeting metabolic syndrome through GM restoration.

Dietary Bacillus velezensis T23 fermented products supplementation improves growth, hepatopancreas and intestine health of Litopenaeus vannamei

This study aimed to elucidate the effects of dietary fermented products of Bacillus velezensis T23 on the growth, immune response and gut microbiota in Pacific white shrimp (Litopenaeus vannamei). Shrimp were fed with diets containing fermentation products of B. velezensis T23 at levels of (0, 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5 g/kg) for 4 weeks, to assess the influence on shrimp growth. The results showed that 0.3 and 0.4 g/kg T23 supplementation improved shrimp growth and feed utilization. Based on these results we selected these three diets (Control, 0.3T23 and 0.4T23) to assess the effect on immune response and gut microbiota of shrimp. Compared with the control, the 0.3T23 and 0.4T23 groups enhanced lipase and α-amylase activities in the gut significantly. Moreover, the 0.4T23 group decreased TAG and MDA levels in hepatopancreas, ALT and AST levels of serum significantly (P < 0.05). In hepatopancreas, CAT and SOD activities were improved observably and the MDA content was reduced markedly in both T23 groups. The expressions of antimicrobial related genes, Cru and peroxinectin in the 0.3T23 group, and proPO and peroxinectin in the 0.4T23 group were up-regulated remarkably (P < 0.05). Moreover, hepatopancreas of shrimp fed with a diet amended with T23 showed a significant down-regulated expression of nf-kb and tnf-α genes, while expressions of tgf-β was considerably up-regulated. Furthermore, serum LPS and LBP contents were reduced markedly in T23 groups. Intestinal SOD and CAT were noteworthy higher in T23 groups (P < 0.05). In the intestine of shrimp fed on the diet enriched with T23 the expression of nf-κb and tnf-α exhibited markedly down-regulated, whereas hif1α was up-regulated (P < 0.05). Besides, in the intestine of shrimp grouped under T23, Cru and peroxinectin genes were markedly up-regulated (P < 0.05). Dietary 0.3 g/kg T23 also upregulated the ratio of Rhodobacteraceae to Vibrionaceae in the gut of the shrimp. Taken together, the inclusion of B. velezensis T23 in the diet of shrimp enhanced the growth and feed utilization, enhanced hepatopancreas and intestine health.

Unraveling the intricate dance of the Mediterranean diet and gut microbiota in autoimmune resilience

The nutritional habits regulate the gut microbiota and increase risk of an autoimmune disease. Western diet is rich in sugars, meat, and poly-unsaturated fatty acids, which lead to dysbiosis of intestinal microbiota, disruption of gut epithelial barrier and chronic mucosal inflammation. In contrast, the Mediterranean Diet (MedDiet) is abundant in ω3 fatty acids, fruits, and vegetables, possessing anti-inflammatory properties that contribute to the restoration of gut eubiosis. Numerous studies have extensively examined the impact of MedDiet and its components on both health and various disease states. Additionally, specific investigations have explored the correlation between MedDiet, microbiota, and the risk of autoimmune diseases. Furthermore, the MedDiet has been linked to a reduced risk of cardiovascular diseases, playing a pivotal role in lowering mortality rates among individuals with autoimmune diseases and comorbidities. The aim of the present review is to specifically highlight current knowledge regarding possible interactions of MedDiet with the patterns of intestinal microbiota focusing on autoimmunity and a blueprint through dietary modulations for the prevention and management of disease's activity and progression.

Succession of tissue microbial community during oat developmental

Investigating oat tissue microflora during its different developmental stages is necessary for understanding its growth and anti-disease mechanism. In this study, 16S rDNA and ITS (Internally Transcribed Spacer) high-throughput sequencing technology were used to explore the microflora diversity of oat tissue. Twenty-seven samples of leaves, stems, and roots from three developmental stages, namely the seedling stage (SS), jointing stage (JS), and maturity stage (MS), underwent sequencing analysis. The analysis showed that 6480 operational taxonomic units (OTUs) were identified in the examined samples, of which 1698 were fungal and 4782 were bacterial. Furthermore, 126 OTUs were shared by fungi, mainly Ascomycota, Basidiomycota, and Mucoromycota at the phylum level, and 39 OTUs were shared by bacteria, mainly Actinobacteriota and Proteobacteria at the phylum level. The microbial diversity of oat tissue in the three developmental stages showed differences, and the α-diversity of the bacteria and β-diversity of the bacteria and fungi in the roots were higher than those of the stems and leaves. Among the bacteria species, Thiiopseudomonas, Rikenellaceae RC9 gut group, and Brevibacterium were predominant in the leaves, MND1 was predominant in the roots, and Lactobacillus was predominant in the stems. Moreover, Brevibacterium maintained a stable state at all growth stages. In the fungal species, Phomatospora was dominant in the leaves, Kondoa was dominant in the roots, and Pyrenophora was dominant in the stems. All species with a high abundance were related to the growth process of oats and antagonistic bacteria. Furthermore, connection modules were denser in bacterial than in fungal populations. The samples were treated with superoxide dismutase and peroxidase. There were 42 strains associated with SOD (Superoxide dismutase), 60 strains associated with POD (Peroxidase), and 38 strains in total, which much higher than fungi. The network analysis showed that bacteria might have more dense connection modules than fungi, The number of bacterial connections to enzymes were much higher than that of fungi. Furthermore, these results provide a basis for further mechanistic research.

Quorum sensing-related activities of beneficial and pathogenic bacteria have important implications for plant and human health

Eukaryotic organisms coevolved with microbes from the environment forming holobiotic meta-genomic units. Members of host-associated microbiomes have commensalic, beneficial/symbiotic, or pathogenic phenotypes. More than 100 years ago, Lorenz Hiltner, pioneer of soil microbiology, introduced the term 'Rhizosphere' to characterize the observation that a high density of saprophytic, beneficial, and pathogenic microbes are attracted by root exudates. The balance between these types of microbes decide about the health of the host. Nowadays we know, that for the interaction of microbes with all eukaryotic hosts similar principles and processes of cooperative and competitive functions are in action. Small diffusible molecules like (phyto)hormones, volatiles and quorum sensing signals are examples for mediators of interspecies and cross-kingdom interactions. Quorum sensing of bacteria is mediated by different autoinducible metabolites in a density-dependent manner. In this perspective publication, the role of QS-related activities for the health of hosts will be discussed focussing mostly on N-acyl-homoserine lactones (AHL). It is also considered that in some cases very close phylogenetic relations exist between plant beneficial and opportunistic human pathogenic bacteria. Based on a genome and system-targeted new understanding, sociomicrobiological solutions are possible for the biocontrol of diseases and the health improvement of eukaryotic hosts.

Investigation of the therapeutic effect of Hedan tablets on high-fat diet-induced obesity in rats by GC-MS technology and 16S ribosomal RNA gene sequencing

Obesity is a persistent metabolic condition resulting from the excessive accumulation or abnormal distribution of body fat. This study aimed to establish an experimental rat model of obesity. The efficacy of treating obesity with Hedan tablets (HDT) was assessed by monitoring changes in weight, blood lipid levels, analyzing inflammatory factors, evaluating organ indices, and observing liver tissue pathology. Furthermore, we utilized 16S ribosomal RNA gene sequencing technology to explore changes in intestinal flora. In addition, GC-MS was used to measure fecal short-chain fatty acid (SCFA) content. The onset of obesity led to a significant decrease in the relative abundance of beneficial bacteria. Conversely, the administration of HDT demonstrated a substantial ability to increase the relative abundance of beneficial bacteria. Obesity resulted in a noteworthy reduction in total SCFAs, a trend significantly reversed in the HDT group. Through correlation analysis, it was determined that HDT mitigated the inflammatory response and improved blood lipid levels by augmenting the abundance of Lactobacillus, Limosilactobacillus, Ruminococcus, and Enterococcus. These particular intestinal flora were identified as regulators of SCFA metabolism, thereby ameliorating metabolic abnormalities associated with obesity. Moreover, HDT intervention elevated the overall fecal concentration of SCFAs, thereby improving metabolic disorders induced by obesity. The anti-obesity effects of HDT are likely attributable to their capacity to influence the composition of intestinal flora and boost SCFA levels in the intestine.

The Effect of Clostridium butyricum on Gut Microbial Changes and Functional Profiles of Metabolism in High-fat Diet-fed Rats Depending on Age and Sex

Background/Aims

A high-fat diet (HFD) causes dysbiosis and promotes inflammatory responses in the colon. This study aims to evaluate the effects of Clostridium butyricum on HFD-induced gut microbial changes in rats.

Methods

Six-week-old Fischer-344 rats with both sexes were given a control or HFD during 8 weeks, and 1-to-100-fold diluted Clostridium butyricum were administered by gavage. Fecal microbiota analyses were conducted using 16S ribosomal RNA metagenomic sequencing and predictive functional profiling of microbial communities in metabolism.

Results

A significant increase in Ruminococcaceae and Lachnospiraceae, which are butyric acid-producing bacterial families, was observed in the probiotics groups depending on sex. In contrast, Akkermansia muciniphila, which increased through a HFD regardless of sex, and decreased in the probiotics groups. A. muciniphila positively correlated with Claudin-1 expression in males (P < 0.001) and negatively correlated with the expression of Claudin-2 (P = 0.042), IL-1β (P = 0.037), and IL-6 (P = 0.044) in females. In terms of functional analyses, a HFD decreased the relative abundances of M00131 (carbohydrate metabolism module), M00579, and M00608 (energy metabolism), and increased those of M00307 (carbohydrate metabolism), regardless of sex. However, these changes recovered especially in male C. butyricum groups. Furthermore, M00131, M00579, and M00608 showed a positive correlation and M00307 showed a negative correlation with the relative abundance of A. muciniphila (P < 0.001).

Conclusion

The beneficial effects of C. butyricum on HFD-induced gut dysbiosis in young male rats originate from the functional profiles of carbohydrate and energy metabolism.

Wet-type grinder-treated okara modulates gut microbiota composition and attenuates obesity in high-fat-fed mice

Wet-type grinder (WG) is a nanofiber technology used to atomize dietary fiber-rich materials. WG-treated okara (WGO) exhibits high dispersion and viscosity similar to those of viscous soluble dietary fibers. Here, we studied the effect of WGO supplementation on obesity and gut microbiota composition in high-fat diet (HFD)-fed mice. WGO intake suppressed body weight gain and fat accumulation, improved glucose tolerance, lowered cholesterol levels, and prevented HFD-induced decrease in muscle mass. WGO supplementation also led to cecum enlargement, lower pH, and higher butyrate production. The bacterial 16S ribosomal RNA genes (16S rDNA) were sequenced to determine the gut microbiota composition of the fecal samples. Sequencing of bacterial 16S rDNA revealed that WGO treatment increased the abundance of butyrate producer Ruminococcus and reduced the abundances of Rikenellaceae, Streptococcaceae, and Prevotellaceae, which are related to metabolic diseases. Metabolomics analysis of the plasma of WGO- and cellulose-treated mice were conducted using ultra-high-performance liquid chromatography-mass spectrometry. Metabolic pathway analysis revealed that the primary bile acid biosynthesis pathway was significantly positively regulated by WGO intake instead of cellulose. These results demonstrate that WG is useful for improving functional properties of okara to prevent metabolic syndromes, including obesity, diabetes, and dyslipidemia.

Sexual dimorphism in the gut microbiota and sexual dimorphism in chronic diseases: Association or causation?

Understanding the sexual dimorphism in diseases is essential to investigate the pathogenesis of some chronic diseases (e.g., autoimmune diseases, etc). The gut microbiota has been found to show a notable impact on the pathology of several chronic diseases in recent years. Intriguingly, the composition of the gut microbiota varies between sexes. Here, we reviewed 'facts and fiction' regarding sexual dimorphism in chronic diseases and sexual dimorphism in the gut microbiota respectively. The association and causative relationship between them aiming to elucidate the pathological mechanisms of sexual dimorphism in chronic diseases were further explored. The development of gender-special food products based on the sexual dimorphism in the gut microbiota were recommended, which would be beneficial to facilitating the personalized treatment.

The Role of the Gut-Joint Axis in the Care of Psoriatic Arthritis: A Two-Sample Bidirectional Mendelian Randomization Study

INTRODUCTION

Observational studies and clinical trials have supported the association between gut microbiota and psoriatic arthritis. However, the causal link between gut microbiota and psoriatic arthritis is still unclear.

METHODS

A two-sample bi-directional Mendelian randomization analysis was performed using the summary statistics of gut microbiota from the largest available genome-wide association study meta-analysis (n = 13,266) conducted by the MiBioGen consortium. The summary statistics of psoriatic arthritis were extracted directly from the FinnGen consortium, which consists of 3186 psoriatic arthritis patients and 24,086 controls. Sensitivity analyses were conducted to assess the validity of our findings. Enrichment analyses were used to investigate the biofunction and pathways.

RESULTS

Inverse variance weighted (IVW) estimates suggested that family Rikenellaceae (P = 0.032) and genus Ruminococcaceae UCG011 (P = 0.014) had a detrimental effect on psoriatic arthritis. We also noticed the negative association between the class Methanobacteria (P = 0.032), order Methanobacteriales (P = 0.032), family Methanobacteriaceae (P = 0.032), genus Eubacterium fissicatena group (P = 0.010), genus Methanobrevibacter (P = 0.031), and genus Butyricicoccus (P = 0.041) with psoriatic arthritis. Sensitivity analyses showed that genus Butyricicoccus had pleiotropy and heterogeneity. According to the results of reverse MR analysis, the causal effect of psoriatic arthritis was found on six taxa, respectivelyc family Clostridiaceae1, family Defluviitaleaceae, genus Butyrivibrio, genus Defluviitaleaceae UCG011, genus Clostridium sensu stricto1, and genus Ruminococcaceae UCG011.

CONCLUSION

This two-sample bidirectional Mendelian randomization analysis suggested that the gut microbiota had a causal effect on psoriatic arthritis and implied the potential role of probiotics in the management and prevention of psoriatic arthritis.

Quantifying Gut Microbial Short-Chain Fatty Acids and Their Isotopomers in Mechanistic Studies Using a Rapid, Readily Expandable LC-MS Platform

Short-chain fatty acids (SCFAs) comprise the largest group of gut microbial fermentation products. While absorption of most nutrients occurs in the small intestine, indigestible dietary components, such as fiber, reach the colon and are processed by the gut microbiome to produce a wide array of metabolites that influence host physiology. Numerous studies have implicated SCFAs as key modulators of host health, such as in regulating irritable bowel syndrome (IBS). However, robust methods are still required for their detection and quantitation to meet the demands of biological studies probing the complex interplay of the gut-host-health paradigm. In this study, a sensitive, rapid-throughput, and readily expandible UHPLC-QqQ-MS platform using 2-PA derivatization was developed for the quantitation of gut-microbially derived SCFAs, related metabolites, and isotopically labeled homologues. The utility of this platform was then demonstrated by investigating the production of SCFAs in cecal contents from mice feeding studies, human fecal bioreactors, and fecal/bacterial fermentations of isotopically labeled dietary carbohydrates. Overall, the workflow proposed in this study serves as an invaluable tool for the rapidly expanding gut-microbiome and precision nutrition research field.

Dynamic changes in the gut microbiota during three consecutive trimesters of pregnancy and their correlation with abnormal glucose and lipid metabolism

INTRODUCTION

During normal pregnancy, changes in the gut microbiota (GM) in response to physiological alterations in hormonal secretion, immune functions and homeostasis have received extensive attention. However, the dynamic changes in the GM during three consecutive trimesters of pregnancy and their relationship with glucose and lipid metabolism have not been reported. In this study, we aimed to investigate the dynamic changes in the diversity and species of the GM during three consecutive trimesters in women who naturally conceived, and their relationships with abnormal fasting blood glucose (FBG) and serum lipid levels.

METHODS

A total of 30 pregnant women without any known chronic or autoimmune inflammatory disease history before pregnancy were enrolled during the first trimester. Serum and stool samples were collected during the first trimester, the second trimester, and the third trimester. Serum samples were tested for FBG and blood lipid levels, and stool specimens were analyzed by 16S rDNA sequencing.

RESULTS

The abundance ratio of bacteroidetes/firmicutes showed an increasing tendency in most of the subjects (19/30, 63.3%) from the first to the third trimester. LEfSe analysis showed that the abundance of Bilophila was significantly increased from the first to the third trimester. In addition, at the genus level, the increased relative abundance of Mitsuokella, Clostridium sensu stricto and Weissella were potentially involved in the development of high FBG during pregnancy. The raised relative abundance of Corynebacterium, Rothia and Granulicatella potentially contributed to the occurrence of dyslipidemia during pregnancy.

CONCLUSIONS

There are dynamic changes in the GM during the three trimesters, and the alterations in some bacterium abundance may contribute to the development of high FBG and dyslipidemia during pregnancy. Monitoring enterotypes and correcting dysbiosis in the first trimester may become new strategies for predicting and preventing glucolipid metabolism disorders during pregnancy.

Time resolved multi-omics reveals diverse metabolic strategies of Salmonella during diet-induced inflammation

With a rise in antibiotic resistance and chronic infection, the metabolic response of Salmonella enterica serovar Typhimurium to various dietary conditions over time remains an understudied avenue for novel, targeted therapeutics. Elucidating how enteric pathogens respond to dietary variation not only helps us decipher the metabolic strategies leveraged for expansion but also assists in proposing targets for therapeutic interventions. Here, we use a multi-omics approach to identify the metabolic response of Salmonella enterica serovar Typhimurium in mice on both a fibrous diet and high-fat diet over time. When comparing Salmonella gene expression between diets, we found a preferential use of respiratory electron acceptors consistent with increased inflammation of the high-fat diet mice. Looking at the high-fat diet over the course of infection, we noticed heterogeneity of samples based on Salmonella ribosomal activity, which separated into three infection phases: early, peak, and late. We identified key respiratory, carbon, and pathogenesis gene expression descriptive of each phase. Surprisingly, we identified genes associated with host-cell entry expressed throughout infection, suggesting sub-populations of Salmonella or stress-induced dysregulation. Collectively, these results highlight not only the sensitivity of Salmonella to its environment but also identify phase-specific genes that may be used as therapeutic targets to reduce infection.

Importance

Identifying novel therapeutic strategies for Salmonella infection that occur in relevant diets and over time is needed with the rise of antibiotic resistance and global shifts towards Western diets that are high in fat and low in fiber. Mice on a high-fat diet are more inflamed compared to those on a fibrous diet, creating an environment that results in more favorable energy generation for Salmonella . Over time on a high-fat diet, we observed differential gene expression across infection phases. Together, these findings reveal the metabolic tuning of Salmonella to dietary and temporal perturbations. Research like this, exploring the dimensions of pathogen metabolic plasticity, can pave the way for rationally designed strategies to control disease.

Nutrition at the Intersection between Gut Microbiota Eubiosis and Effective Management of Type 2 Diabetes

Nutrition is one of the most influential environmental factors in both taxonomical shifts in gut microbiota as well as in the development of type 2 diabetes mellitus (T2DM). Emerging evidence has shown that the effects of nutrition on both these parameters is not mutually exclusive and that changes in gut microbiota and related metabolites such as short-chain fatty acids (SCFAs) and branched-chain amino acids (BCAAs) may influence systemic inflammation and signaling pathways that contribute to pathophysiological processes associated with T2DM. With this background, our review highlights the effects of macronutrients, carbohydrates, proteins, and lipids, as well as micronutrients, vitamins, and minerals, on T2DM, specifically through their alterations in gut microbiota and the metabolites they produce. Additionally, we describe the influences of common food groups, which incorporate varying combinations of these macronutrients and micronutrients, on both microbiota and metabolic parameters in the context of diabetes mellitus. Overall, nutrition is one of the first line modifiable therapies in the management of T2DM and a better understanding of the mechanisms by which gut microbiota influence its pathophysiology provides opportunities for optimizing dietary interventions.

Two-sample Mendelian randomization to study the causal association between gut microbiota and atherosclerosis

Background

According to some recent observational studies, the gut microbiota influences atherosclerosis via the gut microbiota-artery axis. However, the causal role of the gut microbiota in atherosclerosis remains unclear. Therefore, we used a Mendelian randomization (MR) strategy to try to dissect this causative link.

Methods

The biggest known genome-wide association study (GWAS) (n = 13,266) from the MiBioGen collaboration was used to provide summary data on the gut microbiota for a two-sample MR research. Data on atherosclerosis were obtained from publicly available GWAS data from the FinnGen consortium, including cerebral atherosclerosis (104 cases and 218,688 controls), coronary atherosclerosis (23,363 cases and 187,840 controls), and peripheral atherosclerosis (6631 cases and 162,201 controls). The causal link between gut microbiota and atherosclerosis was investigated using inverse variance weighting, MR-Egger, weighted median, weighted mode, and simple mode approaches, among which inverse variance weighting was the main research method. Cochran's Q statistic was used to quantify the heterogeneity of instrumental variables (IVs), and the MR Egger intercept test was used to assess the pleiotropy of IVs.

Results

Inverse-variance-weighted (IVW) estimation showed that genus Ruminiclostridium 9 had a protective influence on cerebral atherosclerosis (OR = 0.10, 95% CI: 0.01-0.67, P = 0.018), while family Rikenellaceae (OR = 5.39, 95% CI: 1.50-19.37, P = 0.010), family Streptococcaceae (OR = 6.87, 95% CI: 1.60-29.49, P = 0.010), genus Paraprevotella (OR = 2.88, 95% CI: 1.18-7.05, P = 0.021), and genus Streptococcus (OR = 5.26, 95% CI: 1.28-21.61, P = 0.021) had pathogenic effects on cerebral atherosclerosis. For family Acidaminococcaceae (OR = 0.87, 95% CI: 0.76-0.99, P = 0.039), the genus Desulfovibrio (OR = 0.89, 95% CI: 0.80-1.00, P = 0.048), the genus RuminococcaceaeUCG010 (OR = 0.80, 95% CI: 0.69-0.94, P = 0.006), and the Firmicutes phyla (OR = 0.87, 95% CI: 0.77-0.98, P = 0.023) were protective against coronary atherosclerosis. However, the genus Catenibacterium (OR = 1.12, 95% CI: 1.00-1.24, P = 0.049) had a pathogenic effect on coronary atherosclerosis. Finally, class Actinobacteria (OR = 0.83, 95% CI: 0.69-0.99, P = 0.036), family Acidaminococcaceae (OR = 0.76, 95% CI: 0.61-0.94, P = 0.013), genus Coprococcus2 (OR = 0.76, 95% CI: 0.60-0.96, P = 0.022), and genus RuminococcaceaeUCG010 (OR = 0.65, 95% CI: 0.46-0.92, P = 0.013), these four microbiota have a protective effect on peripheral atherosclerosis. However, for the genus Lachnoclostridium (OR = 1.25, 95% CI: 1.01-1.56, P = 0.040) and the genus LachnospiraceaeUCG001 (OR = 1.22, 95% CI: 1.04-1.42, P = 0.016), there is a pathogenic role for peripheral atherosclerosis. No heterogeneity was found for instrumental variables, and no considerable horizontal pleiotropy was observed.

Conclusion

We discovered that the presence of probiotics and pathogens in the host is causally associated with atherosclerosis, and atherosclerosis at different sites is causally linked to specific gut microbiota. The specific gut microbiota associated with atherosclerosis identified by Mendelian randomization studies provides precise clinical targets for the treatment of atherosclerosis. In the future, we can further examine the gut microbiota's therapeutic potential for atherosclerosis if we have a better grasp of the causal relationship between it and atherosclerosis.

Temporal and spatial variations in body mass and thermogenic capacity associated with alterations in the gut microbiota and host transcriptome in mammalian herbivores

Most wild animals follow Bergmann's rule and grow in body size as cold stress increases. However, the underlying thermogenic strategies and their relationship with the gut microbiota have not been comprehensively elucidated. Herein, we used the plateau pikas as a model to investigate body mass, thermogenic capacity, host transcriptome, gut microbiota and metabolites collected from seven sites ranging from 3100 to 4700 m on the Qinghai-Tibetan Plateau (QTP) in summer and winter to test the seasonal thermogenesis strategy in small herbivorous mammals. The results showed that the increase in pika body mass with altitude followed Bergmann's rule in summer and an inverted parabolic shape was observed in winter. However, physiological parameters and transcriptome profiles indicated that the thermogenic capacity of pikas increased with altitude in summer and decreased with altitude in winter. The abundance of Firmicutes declined, whereas that of Bacteroidetes significantly increased with altitude in summer. Phenylalanine, tyrosine, and proline were enriched in summer, whereas carnitine and succinate were enriched in winter. Spearman's correlation analysis revealed significant positive correlations between Prevotella, Bacteroides, Ruminococcus, Alistipes and Akkermansia and metabolites of amino acids, pika physiological parameters, and transcriptome profiles. Moreover, metabolites of amino acids further showed significant positive correlations with pika physiological parameters and transcriptome profiles. Our study highlights that the changes in body mass and thermogenic capacity with altitude distinctly differentiate small herbivorous mammals between summer and winter on the QTP, and that the gut microbiota may regulate host thermogenesis through its metabolites.

Nutritional regulation of microbiota-derived metabolites: Implications for immunity and inflammation

Nutrition profoundly shapes immunity and inflammation across the lifespan of mammals, from pre- and post-natal periods to later life. Emerging insights into diet-microbiota interactions indicate that nutrition has a dominant influence on the composition-and metabolic output-of the intestinal microbiota, which in turn has major consequences for host immunity and inflammation. Here, we discuss recent findings that support the concept that dietary effects on microbiota-derived metabolites potently alter immune responses in health and disease. We discuss how specific dietary components and metabolites can be either pro-inflammatory or anti-inflammatory in a context- and tissue-dependent manner during infection, chronic inflammation, and cancer. Together, these studies emphasize the influence of diet-microbiota crosstalk on immune regulation that will have a significant impact on precision nutrition approaches and therapeutic interventions for managing inflammation, infection, and cancer immunotherapy.

Time-restricted feeding ameliorates non-alcoholic fatty liver disease through modulating hepatic nicotinamide metabolism via gut microbiota remodeling

Non-alcoholic fatty liver disease (NAFLD) has emerged as a global health concern, lacking specific therapeutic strategies. Time-restricted feeding (TRF) regimen demonstrated beneficial effects in NAFLD; however, the underlying mechanisms remain unclear. In this study, we established a NAFLD mouse model through a high-fat diet (HFD) and implemented the 16:8 TRF regimen for a duration of 6 weeks. We demonstrated that TRF remarkably alleviated hepatic steatosis in HFD mice. Of note, aldehyde oxidase 1 (AOX1), a key enzyme in hepatic nicotinamide (NAM) catabolism, exhibited apparent upregulation in response to HFD, leading to abnormal accumulation of N-Methyl-6-pyridone-3-carboxamide (N-Me-6-PY, also known as 2PY) and N-Methyl-4-pyridone-5-carboxamide (N-Me-4-PY, also known as 4PY), whereas it was almost restored by TRF. Both N-Me-6-PY and N-Me-4-PY promoted de novo lipogenesis and fatty acid uptake capacities in hepatocyte, and aggravated hepatic steatosis in mice either fed chow diet or HFD. In contrast, pharmacological inhibition of AOX1 was sufficient to ameliorate the hepatic steatosis and lipid metabolic dysregulation induced by HFD. Moreover, transplantation of fecal microbiota efficiently mimicked the modulatory effect of TRF on NAM metabolism, thus mitigating hepatic steatosis and lipid metabolic disturbance, suggesting a gut microbiota-dependent manner. In conclusion, our study reveals the intricate relationship between host NAM metabolic modification and gut microbiota remodeling during the amelioration of NAFLD by TRF, providing promising insights into the prevention and treatment of NAFLD.