Microbiota Metabolism Research Articles

Didymin Ameliorates Dextran Sulfate Sodium (DSS)-Induced Ulcerative Colitis by Regulating Gut Microbiota and Amino Acid Metabolism in Mice.

Background: Didymin is a dietary flavonoid derived from citrus fruits and has been shown to have extensive biological functions, especially anti-inflammatory effects, but its mechanism is unclear. The purpose of this study was to investigate the potential mechanism of didymin that alleviates ulcerative colitis. Methods and Results: Our results indicated that didymin could alleviate the symptoms of ulcerative colitis, as it inhibited the expressions of interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Didymin also promoted the expressions of claudin-1 and zona occludens-1(ZO-1), which are closely related with restoring colon barrier function. Didymin also increased the abundance of Firmicutes and Verrucomicobiota, while decreasing the abundance of Bacteroidota and Proteobacteria. Meanwhile, didymin significantly altered the levels of metabolites related to arginine synthesis and metabolism, and lysine degradation in the colitis mice. Utilizing network pharmacology and molecular docking, our results showed that the metabolites L-ornithine and saccharin could interact with signal transducer and activator of transcription 3 (STAT3) and nuclear factor kappa-B (NF-κB). In this in vitro study, L-ornithine could reduce the expressions of transcription factors STAT3 and NF-κB, and it also inhibited the expressions of IL-6 and IL-1β in the lipopolysaccharides (LPS) induced in RAW264.7 cells, while saccharin had the opposite effect. Conclusions: Taken together, didymin can regulate gut microbiota and alter metabolite products, which can modulate STAT3 and NF-κB pathways and inhibit the expressions of inflammatory factors and inflammatory response in the DSS-induced colitis mice.

Arabinoxylan Alleviates Obesity by Regulating Gut Microbiota and Bile Acid Metabolism.

Overweight and obesity are major and increasingly global public health concern. High intake of dietary fiber is negatively correlated with obesity and obesity-related metabolic diseases. Here, we investigated the impact of arabinoxylan on obesity based on the modification of gut microecology. Arabionxylan reduced body weight and improved glucose metabolism, as well as intestinal barrier function and metabolic endotoxemia in obese mice. Supplementation with arabinoxylan increased the relative abundance of Prevotellaceae_UCG_001, Lachnospiraceae_NK4A136_group, Clostridia_UCG_014, Alistipes, Bacteroides, and Ruminococcus, which was associated with the upregulated 7α-dehydroxylation function and production of secondary bile acids (deoxycholic acid and lithocholic acid). The modification of gut microbiota by arabinoxylan also influenced the production of SCFAs, genistein, daidzein, indolelactic acid, and indoleacetic acid, contributing to the amelioration of obesity. Our study highlights the antiobesity effects of arabinoxylan through the modification of gut microbiota and the production of bioactive metabolites.

Structural characteristics of a purified Evodiae fructus polysaccharide and its gastroprotection and relevant mechanism against alcohol-induced gastric lesions in rats

Evodiae fructus polysaccharide (EFP) has been previously shown to protect against alcohol-induced gastric lesions. However, which and how active fractions in EFP exert gastroprotection remains unclear. This study aimed to characterize the structure of the purified fraction (EFP-2-1) of EFP, and investigate its gastroprotection and underlying mechanisms. EFP-2-1 was obtained through column chromatography, and was characterized using instrumental analytical techniques. Gastroprotective effect of EFP-2-1 was evaluated using alcohol-induced gastric lesions in rats, and its mechanism was explored through proteomics, metabolomics and diversity sequencing. Results showed that EFP-2-1 had a molecular weight of 7.3 kDa, and consisted mainly of rhamnose, galacturonic acid, galactose and arabinose. Its backbone contained HG and RG-I domains, and branched with →5)-α-l-Araf-(1→, α-l-Araf-(1→ and →4)-β-d-Galp-(1→ residues. EFP-2-1 reduced gastric lesions and the levels of MDA, TNF-α and IL-6, activated PPARγ, primarily altered protein digestion and absorption and bile secretion metabolic pathways, regulated gut microbiota like Faecalibaculum and Lachnoclostridium, and increased short-chain fatty acids production. Correlations were observed among the gut microbiota, metabolites and biochemical indexes influenced by EFP-2-1. These findings suggest that EFP-2-1 is an active fraction of EFP for protecting against alcohol-induced gastric lesions, which may be linked to PPARγ activation, gut microbiota and serum metabolism.

The utilization of N-acetylgalactosamine and its effect on the metabolism of amino acids in Erysipelotrichaceae strain

BackgroundThe metabolism of gut microbiota produces bioactive metabolites that modulate host physiology and promote self-growth. Erysipelotrichaceae is one of the most common anaerobic microorganism families in the gut, which has been discovered to play a vital role in host metabolic disorders and inflammatory diseases. Our previous study found that N-acetylgalactosamine (GalNAc) in caecal content of pigs significantly affected the abundance of Erysipelotrichaceae strains. However, it remains unknown how GalNAc feeding in vitro culture affects the expression levels of genes in the GalNAc metabolic pathway and the concentrations of intermediate metabolites in the Erysipelotrichaceae strain. Whether GalNAc feeding should influence the metabolism of other nutrients, such as amino acids, remains unrevealed.ResultsIn this study, whole-genome sequence, transcriptome, and metabolome data were analyzed to assess the utilization of a Erysipelotrichaceae strain on GalNAc. The results showed the presence of a complete GalNAc catabolism pathway in the genome of this Erysipelotrichaceae strain. GalNAc feeding to this Erysipelotrichaceae strain significantly changed the expression levels of genes involved in glycolysis and tricarboxylic acid (TCA) cycle. Meanwhile, the concentrations of lactate, pyruvate, citrate, succinate and malate from the glycolysis and TCA cycle were significantly increased. In addition, transcriptome analysis indicated that the genes involved in the metabolism of amino acids were affected by GalNAc, including lysA (a gene involved in lysine biosynthesis) that was significantly down-regulated. The intracellular concentrations of 14 amino acids in the Erysipelotrichaceae strain were significantly increased after feeding GalNAc.ConclusionsOur findings comfirmed and extended our previous works that demonstrated the utilization of GalNAc by Erysipelotrichaceae strain, and explained the possible mechanism of GalNAc affecting the abundance of Erysipelotrichaceae strain in vitro.

Tumor-colonized Streptococcus mutans metabolically reprograms tumor microenvironment and promotes oral squamous cell carcinoma

BackgroundOral squamous cell carcinoma (OSCC) remains a major death cause in head and neck cancers, but the exact pathogenesis mechanisms of OSCC are largely unclear.ResultsSaliva derived from OSCC patients but not healthy controls (HCs) significantly promotes OSCC development and progression in rat models, and metabolomic analyses reveal saliva of OSCC patients but not HCs and OSCC tissues but not adjacent non-tumor tissues contain higher levels of kynurenic acid (KYNA). Furthermore, large amounts of Streptococcus mutans (S. mutans) colonize in OSCC tumor tissues, and such intratumoral S. mutans mediates KYNA overproductions via utilizing its protein antigen c (PAc). KYNA shifts the cellular types in the tumor microenvironment (TME) of OSCC and predominantly expedites the expansions of S100a8highS100a9high neutrophils to produce more interleukin 1β (IL-1β), which further expands neutrophils and induces CD8 + T cell exhaustion in TME and therefore promotes OSCC. Also, KYNA compromises the therapeutic effects of programmed cell death ligand 1 (PD-L1) and IL-1β blockades in oral carcinogenesis model. Moreover, KYNA-mediated immunosuppressive program and aryl hydrocarbon receptor (AHR) expression correlate with impaired anti-tumor immunity and poorer survival of OSCC patients.ConclusionsThus, aberration of oral microbiota and intratumoral colonization of specific oral bacterium such as S. mutans may increase the production of onco-metabolites, exacerbate the oral mucosal carcinogenesis, reprogram a highly immunosuppressive TME, and promote OSCC, highlighting the potential of interfering with oral microbiota and microbial metabolism for OSCC preventions and therapeutics.5ViVJ5sCbraGF_6Zi1UXojVideo

Characterising and preventing the gut microbiota's inactivation of trifluridine, a colorectal cancer drug

The gut microbiome can metabolise hundreds of drugs, potentially affecting their bioavailability and pharmacological effect. As most gut bacteria reside in the colon, drugs that reach the colon in significant proportions may be most impacted by microbiome metabolism. In this study the anti-colorectal cancer drug trifluridine was used as a model drug for characterising metabolism by the colonic microbiota, identifying correlations between bacterial species and individuals’ rates of microbiome drug inactivation, and developing strategies to prevent drug inactivation following targeted colonic delivery. High performance liquid chromatography and ultra-high performance liquid chromatography coupled with high resolution tandem mass spectrometry demonstrated trifluridine's variable and multi-route metabolism by the faecal microbiota sourced from six healthy humans. Here, four drug metabolites were linked to the microbiome for the first time. Metagenomic sequencing of the human microbiota samples revealed their composition, which facilitated prediction of individual donors’ microbial trifluridine inactivation. Notably, the abundance of Clostridium perfringens strongly correlated with the extent of trifluridine inactivation by microbiota samples after 2 hours (R2 = 0.8966). Finally, several strategies were trialled for the prevention of microbial trifluridine metabolism. It was shown that uridine, a safe and well-tolerated molecule, significantly reduced the microbiota's metabolism of trifluridine by acting as a competitive enzyme inhibitor. Further, uridine was found to provide prebiotic effects. The findings in this study greatly expand knowledge on trifluridine's interactions with the gut microbiome and provide valuable insights for investigating the microbiome metabolism of other drugs. The results demonstrate how protection strategies could enhance the colonic stability of microbiome-sensitive drugs.

Retinol metabolism signaling participates in microbiota-regulated fat deposition in obese mice

Obesity is a global pandemic threatening public health, excess fat accumulation and overweight are its characteristics. In this study, the interplay between gut microbiota and retinol metabolism in modulating fat accumulation was verified. We observed gut microbiota depletion reduced the body weight (P<0.05) and the ratios of white adipose tissues (WATs) to body weight (P<0.05) in high-fat diet (HFD) fed-mice. Both the hepatic metabolomics and transcriptomics analyses confirmed that gut microbiota modulated fat accumulation in obese mice. Besides, the kyoto encyclopedia of genes and genomes (KEGG) analysis and protein-protein interaction (PPI) network of RNA-seq results indicated that retinol metabolism signaling may be involved in the microbiota-regulated fat deposition. Furthermore, activated retinol metabolism signaling by all-trans retinoic acid (atRA) supplementation reduced body weight (P<0.05) and WAT accumulation in obese mice. On the other hand, 16S rRNA gene sequencing of the ileal microbiota suggested that atRA supplementation, in turn, increased the microbial diversity and induced the growth of beneficial bacteria including Parabacteroides, Bacteroides, Clostridium_XVIII, Bifidobacterium, Enterococcus, Bacillus, Leuconostoc, and Lactobacillus in obese mice. Spearman correlation showed that atRA decreased the bacteria (Parvibacter, Asaccharobacter, Romboutsia, and Clostridium_IV) that were positively associated with body and WAT weights, whereas increased the bacteria (Lactobacillus) that were negatively associated with body and WAT weights. Together, this study reveals the interaction between the gut microbiota and retinol metabolism signaling in regulating adipose accumulation and obesity. It is expected of this finding to provide new insights to prevent and develop therapeutic measures of obesity-related metabolic syndrome.

Schisandra chinensis polysaccharide prevents alcohol-associated liver disease in mice by modulating the gut microbiota-tryptophan metabolism-AHR pathway axis

Polysaccharides are one of the main active components of Schisandra chinensis and have been shown to possess diverse biological activities. In this study, we investigated the preventive effect of Schisandra chinensis polysaccharide (SCP) on alcohol-associated liver disease (ALD) by chronic-plus-binge ethanol feeding and the underlying mechanisms. The results suggest that supplementation with SCP prevents ALD by modulating gut microbiota and tryptophan (Trp) metabolism. SCP significantly enriched intestinal Lactobacillus, especially Lactobacillus reuteri, restored the content of intestinal indole derivatives (TRM, IAA, ILA, IALD) that can activate the aromatic hydrocarbon receptor (AHR), increased the colon AHR pathway activity, repaired intestinal barriers damage, reduced the circulating LPS, and inhibited the liver inflammation, oxidative stress, and lipid accumulation. The in vitro Trp metabolizing capacity was used to selected for a strain of L. reuteri whose in vitro proliferation was similarly promoted by SCP. Importantly, the gavage of the L. reuteri increased intestinal TRM content in mice. In addition, its ALD preventive effects were consistent with SCP and dependent on the colon AHR pathway. Our findings confirm that SCP may prevent ALD by mudulating the gut microbial-Trp metabolism-AHR pathway axis, suggesting that supplementation with the prebiotic SCP is an effective way to prevent ALD.

Xiaobugan decoction prevents CCl4-induced acute liver injury by modulating gut microbiota and hepatic metabolism

BackgroundThe liver plays a crucial role in detoxification and metabolism. When its capacity to metabolize foreign substances is exceeded, it can lead to acute liver injury (ALI). Therefore, preventing liver disease and maintaining daily liver health are of utmost importance. Xiaobugan Decoction (XBGD), a traditional Chinese medicine (TCM) formula, is recorded in ‘Fuxingjue’, is used in folk practice to promote liver health and regulate respiration. However, the hepatoprotective mechanisms of XBGD remained unclear. PurposeWe investigated the prophylactic and hepatoprotective effects of XBGD and explored its related molecular mechanisms using a mouse model of carbon tetrachloride (CCl4)-induced ALI. Study design and methodsXBGD composition was determined using analytical methods, and the main compounds were identified using ultra-high-performance liquid chromatography coupled with Q-Exactive focus mass spectrum (UHPLC-QE-MS) and high-performance liquid chromatography (HPLC). A CCl4-induced L02 cell injury model was employed to explore the protective effects of XBGD on liver cells, and a CCl4-induced ALI mouse model was used to investigate the hepatoprotective effects of XBGD. ResultsCellular experiments demonstrated that XBGD had a protective function against L02 cell damage by increasing cell viability, restoring alanine aminotransferase (ALT), aspartate aminotransferase (AST), and superoxide dismutase (SOD) levels, reducing malondialdehyde (MDA) content, and improving mitochondrial membrane potential (ΔΨm). In the mouse ALI model, XBGD prevented ALI by reducing ALT, AST, and alkaline phosphatase (ALP) levels and inhibiting oxidative stress. Quantitative real-time polymerase chain reaction (qPCR), immumohistochemical staining and western blotting results revealed that XBGD exerted hepatoprotective effects by reducing inflammatory responses and inhibiting cell apoptosis. Furthermore, 1H-NMR metabolomics indicated that XBGD regulates hepatic and intestinal metabolism, whereas 16S rDNA sequencing demonstrated the regulatory effects of XBGD on the gut microbiota. Correlation analysis highlighted the close relationship among gut microbiota, metabolites, and ALI indicators. ConclusionsXBGD is a promising TCM for the prevention of CCl4-induced ALI via regulation of microbiota and metabolism. This study provides a new perspective on the development of hepatoprotective measures and the prevention of liver disease in daily life.

Total alkaloids of Aconitum carmichaelii Debx alleviate cisplatin-induced acute renal injury by inhibiting inflammation and oxidative stress related to gut microbiota metabolism

BackgroundCisplatin-induced acute kidney injury (AKI) is a complex and serious clinical issue, representing a major cause of hospital-acquired AKI. Alkaloids are the main active constituents of Aconitum carmichaelii Debx, which exhibit protective effects in several kidney disease models and against other acute organ injuries. However, its activity and mechanism of action in AKI treatment remain unclear. PurposeThis study aimed to elucidate the effect of Aconitum carmichaelii Debx (ACA) in a model of cisplain-induced AKI and comprehensively investigate its underlying mechanisms. MethodsThe major alkaloids in ACA were analyzed using high-performance liquid chromatography. Blood urea nitrogen (BUN) and serum creatine levels were measured using automated biochemical instruments. 16S rRNA sequencing, short-chain fatty acid (SCFA) analysis, fecal microbiota transplantation (FMT), non-targeted metabolomics, and transcriptomics were performed to systematically identify prospective biomarkers after ACA treatment. Anti-inflammatory and anti-oxidative stress activities were monitored using ELISA and western blotting. ResultsFour main compounds (fuziline, neoline, talatisamine, and songorine) were identified in ACA. ACA significantly alleviated cisplatin-induced AKI by reducing (BUN) and serum creatine levels and improving histopathological scores. Moreover, ACA balanced cisplatin-mediated confoundments in microbial composition and function, including decreasing the levels of Escherichia-Shigella, Clostridium, and Ruminococcus, as well as increasing Ligilactobacillus, Anaerotruncus, Bacteroides and Desulfovibrio levels, accompanied by uremic toxin reduction, and augmenting serum SCFAs. The FMT experiments further confirmed that ACA exerts anti-AKI effects by affecting gut microbiota. A multi-omics study has shown that ACA regulates glutathione and tryptophan metabolism and mediates pathways that trigger inflammatory responses. Finally, ACA reduced serum levels of inflammatory factors (IL-1β, IL-6, and TNF-α), restored enzymes of the antioxidative system (SOD and CAT) and GSH values, and decreased monoester diterpene alkaloid levels in the kidney by inhibiting the expression of NF-κB pathway-related proteins and increasing Nrf2/HO-1 pathway-related protein expression. ConclusionACA protects against cisplatin-induced AKI through its anti-inflammatory and antioxidant functions, which may be associated with the restoration of gut microbiota metabolism. ACA is a potential drug for AKI and other forms of organ damage related to the disruption of the gut microbiota.

Exploring the Spatial Variation in the Microbiota and Bile Acid Metabolism of the Compound Stomach in Intensively Farmed Yaks

Yaks are one of the important livestock on the Qinghai–Tibet Plateau, providing abundant dairy and meat products for the local people. The formation of these dairy and meat products mainly relies on the microbiota in their gastrointestinal tract, which digests and metabolizes plant feed. The yak’s gastrointestinal microbiota is closely related to the health and production performance of the host, but the molecular mechanisms of diet-induced effects in intensively farmed yaks remain to be elucidated. In this study, 40 chyme samples were collected from the four stomach chambers of 10 intensively farmed yaks, and the bacterial diversity and bile acid changes in the rumen (SFRM), reticulum (SFRC), omasum (SFOM), and abomasum (SFAM) were systematically analyzed using 16S rRNA sequencing and bile acid metabolism. Our results showed that the gastrointestinal microbiota mainly distributes in the four-chambered stomach, with the highest microbial diversity in the reticulum. There is a highly negative correlation among the microbiota in the four chambers. The dominant bacterial phyla, Bacteroidota and Firmicutes, were identified, with Rikenellaceae_RC9_gut_group being the dominant genus, which potentially helps maintain short-chain fatty acid levels in the stomach. In contrast, the microbiome within the four stomach chambers synergistically and selectively altered the content and diversity of bile acid metabolites in response to intensive feeding. The results of this study provide new insights into the microbiota and bile acid metabolism functions in the rumen, reticulum, omasum, and abomasum of yaks. This can help uncover the role of gastrointestinal microbiota in yak growth and metabolic regulation, while also providing references for improving the production efficiency and health of ruminants.

Phytoactives for Obesity Management: Integrating Nanomedicine for Its Effective Delivery.

Obesity is a global health concern that requires urgent investigation and management. While synthetic anti-obesity medications are available, they come with a high risk of side-effects and variability in their efficacy. Therefore, natural compounds are increasingly being used to treat obesity worldwide. The proposition that naturally occurring compounds, mainly polyphenols, can be effective and safer for obesity management through food and nutrient fortification is strongly supported by extensive experimental research. This review focuses on the pathogenesis of obesity while reviewing the efficacy of an array of phytoactives used for obesity treatment. It details mechanisms such as enzyme inhibition, energy expenditure, appetite suppression, adipocyte differentiation, lipid metabolism, and modulation of gut microbiota. Comprehensive in vitro, in vivo, and preclinical studies underscore the promise of phytoactives in combating obesity, which have been thoroughly reviewed. However, challenges, such as poor bioavailability and metabolism, limit their potential. Advances in nanomedicines may overcome these constraints, offering a new avenue for enhancing the efficacy of phytoactives. Nonetheless, rigorous and targeted clinical trials are essential before applying phytoactives as a primary treatment for obesity.

The gut microbiota of healthy individuals remains resilient in response to the consumption of various dietary fibers

This study focuses on the resilience of gut microbiota during a five-month multi-interventional nutrition trial. The modulatory effects of beta-glucan, rye bran and two dietary fiber mixtures on the fecal pH and compositional changes of the microbiome of healthy subjects were studied. To analyze the stability of intestinal microbiota, we collected an extensive dataset of sequential fecal samples (23–29 from each participant) during a week of the base, beta-glucan consumption and wash-out periods accompanied by the collection of daily food diary data. Microbiota analyses were also conducted after the end of each fiber intake and wash-out period, along with measurements of fecal organic acids and pH. Based on the dominant bacterial taxa, two prevalent microbiota types were identified. The Prevotella-type microbiota responded more to the tested dietary fibers, while the Bacteroides-type microbiota was the least affected. Three microbiota types could not be clustered and behaved differently. Although we noted individual effects of definite fibers on participants’ gut microbiota and metabolic profile, relative abundances of bacteria remained stable in the base period (z-scores − 2.2 to 2.3). In most cases, the bacterial abundances of the final samples remained within the normal fluctuation range stressing out the resilience of healthy microbiota. The pH of all fecal samples varied between 6.1 and 8.3 and was associated with the concentration of organic acids and microbial composition. The effect of dietary fibers on the metabolism of fecal microbiota clearly depended on the individual microbiota type. Combining the analysis of gut microbiota with knowledge of the properties of dietary fibers would provide a powerful strategy for nutrition guidance and disease prevention.

Effects of inactivated Lactobacillus rhamnosus on growth performance, serum indicators, and colonic microbiota and metabolism of weaned piglets

BackgroundTo assess the effects of inactivated Lactobacillus rhamnosus (ILR) on growth performance, serum biochemical indices, colonic microbiota, and metabolomics in weaned piglets, 120 piglets were randomly divided into five groups. Samples in the control group were fed a basal diet, while the experimental ILR1, ILR2, ILR3, and ILR4 groups were fed basal diets supplemented with 0.1%, 0.2%, 0.3%, and 0.4% ILR, respectively. The prefeeding period lasted for 5 days and was followed by a formal period of 28 days.ResultsCompared to the control, the average daily gain increased by 4.38%, 7.98%, 19.32%, and 18.80% for ILR1, ILR2, ILR3, and ILR4, respectively, and the ratio of feed to gain decreased by 0.63%, 3.80%, 12.66%, and 10.76%, respectively. Serum IgA, IgG, IgM, total antioxidant capacity, and glutathione peroxidase levels increased significantly in weaned piglets in the treatment groups. Addition of 0.3% ILR significantly increased the Shannon and Simpson indices of the colonic microbiota in weaned piglets and altered the microbiota composition. Changes in metabolic profiles were observed and were primarily related to the urea cycle, amino acid metabolism, and lipid metabolism.ConclusionILR improved growth performance and serum immunological and biochemical indices and optimized the colonic microbiota structure and metabolism of weaned piglets.

Vinegar-processed Schisandra Chinensis enhanced therapeutic effects on colitis-induced depression through tryptophan metabolism

BackgroundUlcerative colitis (UC) is an inflammatory bowel disease characterized by its incurable nature and undefined etiology, which is often accompanied by a high prevalence of comorbid depression. The gut-brain axis has emerged as a promising treatment target in recent years. Purpose: This study aimed to investigate how vinegar-processed Schisandra Chinensis (VSC) enhances therapeutic effects on depressive behavior in chronic UC mice. Methods: A chronic UC model was induced in mice using dextran sulfate sodium. The therapeutic effects of both raw and vinegar-processed Schisandra Chinensis on UC and associated depressive symptoms were assessed. Colonic mucosal damage was evaluated using hematoxylin and eosin (H&E) and Alcian blue staining. The integrity of the blood-brain barrier (BBB) and synaptic structures was visualized via transmission electron microscopy (TEM). Enzyme-linked immunosorbent assay (ELISA) was employed to quantify inflammatory cytokine levels in the colon, serum, and brain, while western blotting was performed for protein expression analysis. Additionally, metagenomic analysis was conducted to investigate gut microbiota composition. Nissl staining and immunofluorescence were used to assess hippocampal neuronal damage, and behavioral assessments including the morris water maze, open field test, forced swimming test and tail suspension test, were implemented to evaluate depressive states. Serum metabolites were analyzed using UPLC-MS/MS. Results: Both raw and vinegar-processed Schisandra Chinensis significantly upregulated aryl hydrocarbon receptor (AhR), inhibited NF-κB p-p65 activation, and reduced levels of pro-inflammatory cytokine. These treatments also enhanced the expression of tight junction proteins, restored colonic mucosal and BBB integrity, alleviated damage to hippocampal neurons, and improved synaptic structure. Behavioral assessments indicated that VSC was particularly effective in ameliorating depressive-like behaviors in chronic UC mice. In the gut, both treatments reshaped the gut microbial composition, restoring the relative abundance of Duncaniella, Candidatus_Amulumruptor, Alistipes, Parabacteroides, Lachnospiraceae_bacterium, uncultured_Bacteroides_sp., Candidatus_Amulumruptor_caecigallinarius, with VSC showing more pronounced effects. Serum metabolomics revealed an increase in tryptophan levels and a decrease in kynurenine and xanthurenic acid levels with VSC, indicating that tryptophan metabolism shifted from the kynurenine pathway to the 5-HT or indole pathway. However, this phenomenon did not occur with Schisandra Chinensis (SC). Conclusion: This study demonstrated that the disruption of tryptophan metabolic balance served as a biological mechanism underlying the occurrence of depressive behaviors induced by UC. The application of SC following vinegar processing enhanced its regulatory effects on gut microbiota and tryptophan metabolism. This findings provided a new insight for the clinical management of gut-brain comorbidities.

Pentachlorophenol Exposure Delays the Recovery of Colitis in Association With Altered Gut Microbiota and Purine Metabolism.

Pentachlorophenol (PCP) was used widely as preservative and biocide and has been banned due to with various harmful effects, such as carcinogenicity and teratogenicity. However, the effects of PCP on colitis induced by dextrose sodium sulfate (DSS) remain largely unknown. Serum metabolomics and gut microbiota were investigated to elucidate the underlying mechanisms. Exposure to 20 μg/L PCP aggravated DSS-induced body weight loss, colon shortening, severe histological injuries, and upregulation of TNFα, iNOS, IL-1β, and IL-6. Serum metabolomics showed that both DSS and PCP could significantly disrupted tryptophan metabolism in normal mice. Interestingly, PCP exposure intensified the disturbance in purine metabolism but not tryptophan metabolism caused by DSS. Quantitative analysis of tryptophan and metabolites further confirmed that PCP exposure significantly increased the serum contents of serotonin, adenine, guanine, guanosine, inosine monophosphate (IMP), inosine, and hypoxanthine in DSS-treated mice. The overall gut microbial community was significantly modified by PCP and DSS treatment alone. Rikenellaceae_RC9_Gut_group, Colidextribacter, and Desulfovibrio were more abundant in colitis mice following PCP exposure. Further integrative analysis of differential bacteria and purine metabolites highlighted a significant correlation between Desulfovibrio and several purine metabolites, including guanine, guanosine, hypoxanthine, IMP, and inosine. Adenosine ribonucleotides de novo biosynthesis, inosine-5'-phosphate biosynthesis I, and urate biosynthesis/inosine 5'-phosphate degradation pathways were depleted in colitis mice upon PCP treatment. Taken together, PCP exposure delayed the recovery of colitis induced by DSS in association with altered gut microbiota and serum metabolites, which were enriched in tryptophan and purine metabolism.

Unveiling the dynamic processes of dietary advanced glycation end-products (dAGEs) in absorption, accumulation, and gut microbiota metabolism.

This study delves into the dynamics of dietary advanced glycation end-products (dAGEs) on host health and gut microbiota. Using 13C-labeled carboxymethyllysine (CML) bound casein, we identify bound AGEs as the primary entry route, in contrast to free AGEs dominating urinary excretion. Specifically, our results show that the kidneys accumulate 1.5 times more dAGEs than the liver. A high AGE (HA) diet prompts rapid gut microbiota changes, with an initial stress-induced mutation phase, evidenced by a 20% increase in Bacteroides and Parabacteroides within the first week, followed by stabilization. These bacteria emerge as potential dAGE-utilizing bacteria, influencing the microbiota composition. Concurrent metabolic shifts affect lipid and carbohydrate pathways, with lipid metabolism alterations persisting over time, impacting host metabolic homeostasis. This study illuminates the intricate interplay between dietary AGEs, gut microbiota, and host health, offering insights into the health consequences of short- and long-term HA dietary patterns.

236 Increased dietary protein supports key metabolic and intestinal tissue functions in weaned pigs, without increasing gastrointestinal pathogen abundance

Abstract A common dietary strategy to prevent diarrhea in weaned pigs is feeding low protein diets in the period immediately following weaning. The goal of this intervention is to decrease dietary protein sufficiently to reduce pathogen proliferation and protein fermentation without negatively impacting growth performance. One potential alternative to low protein diets is provision of dietary fiber. However, many studies examining the role of protein and fiber on gastrointestinal microbiota and post-weaning diarrhea are complicated by the presence of other substrates, including polyphenols and antinutritional factors in complex ingredients. To assess the role of increased protein and fiber on gut microbiota and host metabolism, semi-purified diets differing in crude protein (CP) and crude fiber (CF) were fed to weaned pigs (n = 40; 28 d of age). Diets with high protein (HP; CP 24.3%, CF 6.4%), high fiber (HF; CP 18.9%, CF 9.4%), or both (HFHP; CP 24.9%, CF 9.5%) were compared with a control (CON; CP 18.1%, CF 6.3%) diet with industry standard crude protein and fiber levels (n = 10/group). Growth performance and diarrhea prevalence were measured alongside gut microbiota composition and metabolites. Pigs fed the HP and HFHP diets had significantly improved feed efficiency compared with both CON and HF diets. Increased protein fermentation, measured through production of biogenic amines, was observed in HP fed animals (P &amp;lt; 0.001). These effects were mitigated by addition of fiber in the HFHP fed pigs. Despite increased markers of protein fermentation, post-weaning diarrhea incidence was not greater in HP fed animals and no increases in gastrointestinal pathogen abundance were detected. Metabolomic and transcriptomic analyses identified critical alterations in host metabolism and cecal transcriptome in the CON compared with the HP fed animals. While all diets were formulated to meet the dietary requirements of weaned pigs, diets with lower protein levels (CON and HF) induced alteration in transcripts from the serine synthesis pathways (P &amp;lt; 0.001) and integrated stress response (P &amp;lt; 0.001) in cecal tissue alongside increases in metabolic pathways related to lysine degradation (P = 0.005). These results challenge the current practice of low protein feeding following weaning by demonstrating a detrimental effect of low protein diets on intestinal cell function and muscle accretion. This suggests that with careful ingredient selection, increased dietary protein post-weaning could better support pig health and performance compared with current industry standard diets.

Tauroursodeoxycholic Acid Improves Nonalcoholic Fatty Liver Disease by Regulating Gut Microbiota and Bile Acid Metabolism.

Tauroursodeoxycholic acid (TUDCA) is a synthetic bile salt that has demonstrated efficacy in the management of hepatobiliary disorders. However, its specific mechanism of action in preventing and treating nonalcoholic fatty liver disease (NAFLD) remains incompletely understood. This research revealed that TUDCA treatment can reduce obesity and hepatic lipid buildup, enhance intestinal barrier function and microbial balance, and increase the presence of Allobaculum and Bifidobacterium in NAFLD mouse models. TUDCA can influence the activity of farnesoid X receptor (FXR) and cholesterol 7α-hydroxylase (CYP7A1), resulting in higher hepatic bile acid levels and increased expression of sodium taurocholate cotransporting polypeptide (NTCP), leading to elevated concentrations of liver-bound bile acids in mice. Furthermore, TUDCA can inhibit the expression of FXR and fatty acid transport protein 5 (FATP5), thereby reducing fatty acid absorption and hepatic lipid accumulation. This investigation provides new insights into the potential of TUDCA for preventing and treating NAFLD.

Pangenome analysis of Clostridium scindens : a collection of diverse bile acid and steroid metabolizing commensal gut bacterial strains.

Clostridium scindens is a commensal gut bacterium capable of forming the secondary bile acids deoxycholic acid and lithocholic acid from the primary bile acids cholic acid and chenodeoxycholic acid, respectively, as well as converting glucocorticoids to androgens. Historically, only two strains, C. scindens ATCC 35704 and C. scindens VPI 12708, have been characterized in vitro and in vivo to any significant extent. The formation of secondary bile acids is important in maintaining normal gastrointestinal function, in regulating the structure of the gut microbiome, in the etiology of such diseases such as cancers of the GI tract, and in the prevention of Clostridium difficile infection. We therefore wanted to determine the pangenome of 34 cultured strains of C. scindens and a set of 200 metagenome-assembled genomes (MAGs) to understand the variability among strains. The results indicate that the 34 strains of C. scindens have an open pangenome with 12,720 orthologous gene groups, and a core genome with 1,630 gene families, in addition to 7,051 and 4,039 gene families in the accessory and unique (i.e., strain-exclusive) genomes, respectively. The core genome contains 39% of the proteins with predicted metabolic function, and, in the unique genome, the function of storage and processing of information prevails, with 34% of the proteins being in that category. The pangenome profile including the MAGs also proved to be open. The presence of bile acid inducible ( bai ) and steroid-17,20-desmolase ( des ) genes was identified among groups of strains. The analysis reveals that C. scindens strains are distributed into two clades, indicating the possible onset of C. scindens separation into two species, confirmed by gene content, phylogenomic, and average nucleotide identity (ANI) analyses. This study provides insight into the structure and function of the C. scindens pangenome, offering a genetic foundation of significance for many aspects of research on the intestinal microbiota and bile acid metabolism.