Hepatic protein phosphatase 1 regulatory subunit 3G alleviates obesity and liver steatosis by regulating the gut microbiota and bile acid metabolism.

Intestinal dysbiosis and disrupted bile acid (BA) homeostasis are associated with obesity, but the precise mechanisms remain insufficiently explored. Hepatic protein phosphatase 1 regulatory subunit 3G (PPP1R3G) plays a pivotal role in regulating glycolipid metabolism; nevertheless, its obesity-combatting potency remains unclear. In this study, a substantial reduction was observed in serum PPP1R3G levels in high-body mass index (BMI) and high-fat diet (HFD)-exposed mice, establishing a positive correlation between PPP1R3G and non-12α-hydroxylated (non-12-OH) BA content. Additionally, hepatocyte-specific overexpression of Ppp1r3g (PPP1R3G HOE) mitigated HFD-induced obesity as evidenced by reduced weight, fat mass, and an improved serum lipid profile; hepatic steatosis alleviation was confirmed by normalized liver enzymes and histology. PPP1R3G HOE considerably impacted systemic BA homeostasis, which notably increased the non-12-OH BAs ratio, particularly lithocholic acid (LCA). 16S ribosomal DNA (16S rDNA) sequencing assay indicated that PPP1R3G HOE reversed HFD-induced gut dysbiosis by reducing the Firmicutes/Bacteroidetes ratio and Lactobacillus population, and elevating the relative abundance of Blautia, which exhibited a positive correlation with serum LCA levels. A fecal microbiome transplantation test confirmed that the anti-obesity effect of hepatic PPP1R3G was gut microbiota-dependent. Mechanistically, PPP1R3G HOE markedly suppressed hepatic cholesterol 7α-hydroxylase (CYP7A1) and sterol-12α-hydroxylase (CYP8B1), and concurrently upregulated oxysterol 7-α hydroxylase and G protein-coupled BA receptor 5 (TGR5) expression under HFD conditions. Furthermore, LCA administration significantly mitigated the HFD-induced obesity phenotype and elevated non-12-OH BA levels. These findings emphasize the significance of hepatic PPP1R3G in ameliorating diet-induced adiposity and hepatic steatosis through the gut microbiota-BA axis, which may serve as potential therapeutic targets for obesity-related disorders.

Role of ACSL4 in modulating farnesoid X receptor expression and M2 macrophage polarization in HBV-induced hepatocellular carcinoma.

The intricate relationship between bile acid (BA) metabolism, M2 macrophage polarization, and hepatitis B virus-hepatocellular carcinoma (HBV-HCC) necessitates a thorough investigation of ACSL4's (acyl-CoA synthetase long-chain family member 4) role. This study combines advanced bioinformatics and experimental methods to elucidate ACSL4's significance in HBV-HCC development. Using bioinformatics, we identified differentially expressed genes in HBV-HCC. STRING and gene set enrichment analysis analyses were employed to pinpoint critical genes and pathways. Immunoinfiltration analysis, along with in vitro and in vivo experiments, assessed M2 macrophage polarization and related factors. ACSL4 emerged as a pivotal gene influencing HBV-HCC. In HBV-HCC liver tissues, ACSL4 exhibited upregulation, along with increased levels of M2 macrophage markers and BA. Silencing ACSL4 led to heightened farnesoid X receptor (FXR) expression, reduced BA levels, and hindered M2 macrophage polarization, thereby improving HBV-HCC conditions. This study underscores ACSL4's significant role in HBV-HCC progression. ACSL4 modulates BA-mediated M2 macrophage polarization and FXR expression, shedding light on potential therapeutic targets and novel insights into HBV-HCC pathogenesis.

Triclosan exposure causes abnormal bile acid metabolism through IL-1ß-NF-κB-Fxr signaling pathway.

Triclosan (TCS) is an eminent antibacterial agent. However, extensive usage causes potential health risks like hepatotoxicity, intestinal damage, kidney injury, etc. Existing studies suggested that TCS would disrupt bile acid (BA) enterohepatic circulation, but its toxic mechanism remains unclear. Hence, the current study established an 8-week TCS exposure model to explore its potential toxic mechanism. The results discovered 8 weeks consecutive administration of TCS induced distinct programmed cell death, inflammatory cell activation and recruitment, and excessive BA accumulation in liver. Furthermore, the expression of BA synthesis and transport associated genes were significantly dysregulated upon TCS treatment. Additional mechanism exploration revealed that Fxr inhibition induced by TCS would be the leading cause for unusual BA biosynthesis and transport. Subsequent Fxr up-stream investigation uncovered TCS exposure caused pyroptosis and its associated IL-1ß would be the reason for Fxr reduction mediated by NF-κB. NF-κB blocking by dimethylaminoparthenolide ameliorated TCS induced BA disorder which confirmed the contribution of NF-κB in Fxr repression. To sum up, our findings conclud TCS-caused BA disorder is attributed to Fxr inhibition, which is regulated by the IL-1ß-NF-κB signaling pathway. Hence, we suggest Fxr would be a potential target for abnormal BA stimulated by TCS and its analogs.

Bile acid metabolism modulates intestinal immunity involved in ulcerative colitis progression.

The bile acids (BA) in the intestine promote inflammation by interacting with immune cells, playing a crucial role in the progression of UC, but the specific mechanism between the two remains elusive. This study aims to explore the relationship between BAMand UC inflammation and determine its potential mechanisms.Firstly, we employed a hybrid approach using Lasso regression and support vector machine (SVM) feature selection in bioinformatics to identify genes linked to UC and BAM. The relationship between these genes and immune infiltration was explored, along with their correlation with immune factors in the Tumor-Immune System Interaction Database (TISIDB) database. Gene Set Enrichment Analysis (GSEA) pathway enrichment analysis was then used to predict signaling pathways associated with key genes in UC. Single-cell data from the GSE13464 dataset was also analyzed. Finally, Five differentially expressed genes (DEGs) related to BAM (APOA1, AMACR, PEX19, CH25H, and AQP9) were significantly upregulated/downregulated in UC immune cells. The expression of important genes in UC tissue was confirmed in the experimental validation section and AQP9, which showed significant differential expression, was chosen for further validation. The results showed that the AQP9 gene may regulate the IFN - γ/JAK signaling axis, thereby promoting CD8+T cell activation. This research has greatly advanced our comprehension of the pathogenesis and underlying mechanism of BAM in immune cells linked to UC.

A mixed animal and plant protein source replacing fishmeal affects bile acid metabolism and apoptosis in largemouth bass (Micropterus salmoides).

Chicken meal, shrimp meal, blood meal, and soybean protein concentrate (SPC) are common alternatives to fishmeal. This study used them to prepare three diets with different levels of fishmeal (FM48, FM40, FM32) for largemouth bass (Micropterus salmoides). The results found no significant difference in the growth performance of largemouth bass fed different diets. Mixed protein increased the total cholesterol (T-CHO) content in plasma, and reduced the total superoxide dismutase (T-SOD) activity in plasma and liver. Targeted metabolomics analysis found that the low fishmeal diets affected the cholesterol and bile acid metabolism of largemouth bass. Mixed protein inhibited cyp7a1 and enhanced hmgcr and pparγ mRNA levels, as well as enhanced the expression levels of FXR in the liver. The fish fed FM32 diet showed inhibited fxr, rxrα and cyp7a1 mRNA levels in the intestine. The results of TUNEL fluorescence staining showed that mixed protein induced apoptosis in largemouth bass. The caspase 3 and caspase 9 mRNA levels in the fish fed FM40 and FM32 diet significantly increased, as well as the expression levels of CASPASE 3. The experiment also found that it could induce oxidative stress and endoplasmic reticulum stress. In conclusion, replacement of fishmeal with mixed animal and plant protein diets did not affect the growth performance, but the health and bile acid metabolism of largemouth bass was affected when the fishmeal level was reduced to 32 %.

Neuroprotective effects of mesenchymal stromal cells in mouse models of Alzheimer's Disease: The Mediating role of gut microbes and their metabolites via the Microbiome-Gut-Brain axis.

The intricacy and multifaceted nature of Alzheimer's disease (AD) necessitate therapies that target multiple aspects of the disease. Mesenchymal stromal cells (MSCs) emerge as potential agents to mitigate AD symptoms; however, whether their therapeutic efficacy involves modulation of gut microbiota and the microbiome-gut-brain axis (MGBA) remains unexplored. In this study, we evaluated the effects of three distinct MSCs types-derived from the umbilical cord (UCMSC), dental pulp (SHED), and adipose tissue (ADSC)-in an APP/PS1 mouse model of AD. In comparison to saline control, MSCs administration resulted in a significant reduction of behavioral disturbances, amyloid plaques, and phosphorylated tau in the hippocampus and frontal cortex, accompanied by an increase in neuronal count and Nissl body density across AD-afflicted brain regions. Through 16S rRNA gene sequencing, we identified partial restoration of gut microbial balance in AD mice post-MSCs treatment, evidenced by the elevation of neuroprotective Akkermansia and reduction of the AD-associated Sphingomonas. To examine whether gut microbiota involved in MSCs efficacy in treating AD, SHED with better anti-inflammatory and gut microbiota recovery effects among three MSCs, and another AD model 5 × FAD mice with earlier and more pathological proteins in brain than APP/PS1, were selected for further studies. Antibiotic-mediated gut microbial inactivation attenuated MSCs efficacy in 5 × FAD mice, implicating the involvement of gut microbiota in the therapeutic mechanism. Functional analysis of altered gut microbiota and targeted bile acid metabolism profiling revealed a significant enhancement in bile acid variety following MSCs therapy. A chief bile acid constituent, taurocholic acid (TCA), was orally administered to AD mice and similarly abated AD symptoms. Nonetheless, the disruption of intestinal neuronal integrity with enterotoxin abrogated the ameliorative impact of both MSCs and TCA treatments. Collectively, our findings substantiate that MSCs confer therapeutic benefits in AD within a paradigm that primarily involves regulation of gut microbiota and their metabolites through the MGBA.

CYP8B1 Catalyzes 12alpha-hydroxylation of C27 Bile Acid: In Vitro Conversion of Dihydroxycoprostanic Acid into Trihydroxycoprostanic Acid.

CYP8B1 is the unique P450 enzyme with sterol 12-oxidation activity, playing an exclusive role in 12α-hydroxylating intermediates along the bile acid (BA) synthesis pathway. Despite the long history of BA metabolism studies, it is unclear whether CYP8B1 catalyzes 12α-hydroxylation of C27 BAs, the key intermediates shuttling between mitochondria and peroxisomes. This work provides robust in vitro evidence that both microsomal and recombinant CYP8B1 enzymes catalyze the 12α-hydroxylation of dihydroxycoprostanic acid (DHCA) into trihydroxycoprostanic acid (THCA). On the one hand, DHCA 12α-hydroxylation reactivity is conservatively detected in liver microsomes of both human and preclinical animals. The reactivity of human tissue fractions conforms well with the selectivity of CYP8B1 mRNA expression, while the contribution of P450 enzymes other than CYP8B1 is excluded by reaction phenotyping in commercial recombinant enzymes. On the other hand, we prepared functional recombinant human CYP8B1 proteins according to a recently published protocol. Titration of the purified CYP8B1 proteins with either C4 (7α-hydroxy-4-cholesten-3-one) or DHCA yields expected blue shifts of the heme Soret peak (type I binding). The recombinant CYP8B1 proteins efficiently catalyze 12α-hydroxylation of both DHCA and C4, with Km of 3.0 and 1.9 µM and kcat of 3.2 and 2.6 min-1, respectively. In summary, the confirmed role of CYP8B1 in 12α-hydroxylation of C27 BAs has furnished the forgotten passageway in the BA synthesis pathway. The present finding might have opened a new window to consider the biology of CYP8B1 in glucolipid metabolism and to evaluate CYP8B1 inhibition as a therapeutic approach of crucial interest for metabolic diseases. Significance Statement Academic community has spent about 90 years interpreting the synthesis of bile acids. However, the 12α-hydroxylation of intermediates catalyzed by CYP8B1 is not completely mapped on the classic pathway, particularly for the C27 bile acids, the pivotal intermediates shuttling between mitochondria and peroxisomes. This work discloses the forgotten 12α-hydroxylation pathway from dihydroxycoprostanic acid into trihydroxycoprostanic acid. The present finding may facilitate evaluating CYP8B1 inhibition as a therapeutic approach of crucial interest for metabolic diseases.

Lingguizhugan oral solution alleviates MASLD by regulating bile acids metabolism and the gut microbiota through activating FXR/TGR5 signaling pathways.

Background: The preservation of the Lingguizhugan (LGZG) decoction and patient compliance issue often limit the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD). Hence, herein, an LGZG oral solution was developed for alleviating MASLD. Additionally, the potential mechanisms underlying LGZG-mediated MASLD mitigation were explored. Methods: A MASLD mouse model was constructed using oleic and palmitic acid-induced LO2 cells and a high-fat diet. The apoptosis, lipid deposition, and mouse liver function were analyzed to assess the therapeutic effects of the LGZG oral solution on MASLD. Serum untargeted metabolomics, gut microbiota, bile acid (BA) metabolism, immunohistochemistry, and Western blotting analyses were performed to investigate the potential mechanism of action of LGZG oral solution on MASLD. Results: The LGZG oral solution ameliorated lipid deposition, oxidative stress, inflammation, and pathological damage. Serum untargeted metabolomics results revealed the LGZG-mediated regulation of the primary BA biosynthetic pathway. The 16S ribosomal RNA sequencing of the fecal microbiota showed that LGZG oral solution increased the relative abundance of the BA metabolism-associated Bacteroides, Akkermansia, and decreased that of Lactobacillus. Additionally, the BA metabolism analysis results revealed a decrease in the total taurine-α/ß-muricholic acid levels, whereas those of deoxycholic acid were increased, which activated specific receptors in the liver and ileum, including farnesoid X receptor (FXR) and takeda G protein-coupled receptor 5 (TGR5). Activation of FXR resulted in an increase in short heterodimer partner and subsequent inhibition of cholesterol 7α-hydroxylase and sterol regulatory element-binding protein-1c expression, and activation of FXR also results in the upregulation of fibroblast growth factor 15/19 expression, and consequently inhibition of cholesterol 7α-hydroxylase, which correlated with hepatic BA synthesis and lipogenesis, ultimately attenuating lipid deposition and bile acid stasis, thereby improving MASLD. Conclusion: Altogether, the findings of this study suggest that modulating microbiota-BA-FXR/TGR5 signaling pathway may be a potential mechanism of action of LGZG oral solution for the treatment of MASLD.

Silymarin targets the FXR protein through microbial metabolite 7-keto-deoxycholic acid to treat MASLD in obese mice.

BACKGROUND: Silymarin is recognized for its excellent hepato-protective properties. Recent clinical studies have examined the effects of silymarin on metabolic dysfunction-associated steatotic liver disease (MASLD), highlighting the necessity of further exploration into optimal dosages, active components, and mechanisms of action. METHODS AND RESULTS: This study assessed the anti-inflammatory activity of the principal constituents of silymarin at the cellular level. The therapeutic effects of varying silymarin doses and components on MASLD in mouse models induced by a high-fat diet (HFD) were also examined. These findings indicate the superior efficacy of 80 mg kg-1 silymarin in mitigating liver steatosis and reducing lipid accumulation compared to 30 mg kg-1 silymarin or a combination of silybin and isosilybin A. The mechanism of silymarin involves regulating gut microbiota homeostasis and influencing the TLR4/NF-κB signalling pathway through LPS. Bile acid-targeted metabolomics analysis revealed that silymarin significantly decreases the HFD-induced increase in 7-keto-deoxycholic acid (7-KDCA). Further investigations suggested that 7-KDCA as an antagonist targeted farnesoid X receptor (FXR) and that both silybin and isosilybin A could directly interact with FXR. CONCLUSION: These findings elucidate that 80 mg kg-1 of silymarin can exert therapeutic effects on MASLD mice and offer novel insights into the mechanism of silymarin in treating MASLD. Especially, it was found that silymarin could regulate bile acid metabolism, reduce the concentration of 7-KDCA, and thus perform negative feedback regulation on FXR.

Impacts of prenatal environmental exposures on fetal-placental-maternal bile acid homeostasis and long-term health in offspring.

During pregnancy, the maternal body undergoes a series of adaptative physiological changes, leading to a slight increase in serum bile acid (BA) levels. Although the fetal liver can synthesize BAs since the first trimester through the alternative pathway, the BA metabolic system is immature in the fetus. Compared to adults, the fetus has a distinct composition of BA pool and limited expression of BA synthesis enzymes and transporters. Besides, the "enterohepatic circulation" of BAs is absent in fetus. Thus, fetal BAs need to be transported to the mother through the placenta for further metabolism and excretion, and maternal BAs can also be transported to the fetus. That is what we call the "fetal-placental-maternal BA circulation". Various BA transporters and nuclear receptors are essential for maintaining the balance of this BA circulation to ensure normal fetal development. However, prenatal adverse environments can alter fetal BA metabolism, resulting in intrauterine developmental abnormalities and susceptibility to a variety of adult chronic diseases. This review summarizes the current understanding of the fetal-placental-maternal BA circulation and discusses the effects of prenatal adverse environments on this particular BA circulation, aiming to provide a theoretical basis for exploring early prevention and treatment strategies for BA metabolism-associated adverse pregnancy outcomes and long-term impairments.

Candida tropicalis ZD-3 prevents excessive fat deposition by regulating ileal microbiota and bile acids enterohepatic circulation in broilers.

Introduction: Evidence suggests that the dietary intake of Candida tropicalisZD-3 (ZD-3) has various health benefits, but the treatment mechanisms and effects remain unclear. The aim of this study investigates the effect of ZD-3 on reducing fat deposition in broilers and the underlying mechanism. Methods: 180 one-day-old, yellow-feathered broilers were randomly divided into three groups: control (CON) group fed a basal diet, an active Candida tropicalis ZD-3 (ZD) group supplemented with ZD, and a heat-inactivated Candida tropicalis ZD-3 (HZD) group supplemented with HZD. The experiment lasted for 28 d. Results: The ZD and HZD treatments significantly reduced the abdominal fat index (p < 0.05), decreased TG levels in serum and liver (p < 0.05), altered the ileal microbial composition by reducing the Firmicutes to Bacteroidetes (F/B) ratio. Additionally, the ZD and HZD treatments reduced liver cholesterol by decreasing ileal FXR-FGF19 signaling and increasing liver FXR-SHP signaling (p < 0.05). The ZD and HZD treatments also changed liver PC and TG classes lipid composition, regulating liver lipid metabolism by promoting TG degradation and modulating the signal transduction of the cell membrane. Discussion: Overall, ZD-3 was effective in improving lipid metabolism in broilers by regulating the ileal microbial composition and BAs enterohepatic circulation. This study provides a theoretical basis for the development and application of ZD-3 for the regulation of lipid metabolism in broilers.

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.

Emodin alleviates cholestatic liver injury by modulating Sirt1/Fxr signaling pathways.

Emodin (EMO) has the effect of anti-cholestasis induced by alpha-naphthylisothiocyanate (ANIT). But its mechanism is still unclear. The farnesoid X receptor (Fxr) is the master bile acid nuclear receptor. Recent studies have reported that Sirtuin 1 (Sirt1) can regulate the activities of Fxr. The purpose of the current study was to investigate the mechanism of EMO against ANIT-induced liver injury based on Sirt1/Fxr signaling pathway. The ANIT-induced cholestatic rats were used with or without EMO treatment. Serum biochemical indicators, as well as liver histopathological changes were examined. The genes expressions of Sirt1, Fxr, Shp, Bsep and Mrp2 were detected. The expressions of Sirt1, Fxr and their downstream related genes were investigated in vitro. The results showed that EMO significantly alleviated ANIT-induced liver injury in rats, and increased Sirt1, Fxr, Shp, Bsep and Mrp2 gene expression in liver, while decreased the expression of Cyp7a1. EMO significantly activated Fxr, while Sirt1 inhibitor and Sirt1 gene silencing significantly reduced Fxr activity in vitro. Collectively, EMO in the right dose has a protective effect on liver injury induced by ANIT, and the mechanism may be through activation of Fxr by Sirt1, thus regulating bile acid metabolism, and reducing bile acid load in hepatocytes.

Bacteroides fragilis alleviates necrotizing enterocolitis through restoring bile acid metabolism balance using bile salt hydrolase and inhibiting FXR-NLRP3 signaling pathway.

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in premature infants with no specific treatments available. We aimed to identify the molecular mechanisms underlying NEC and investigate the therapeutic effects of Bacteroides fragilis on NEC. Clinical samples of infant feces, bile acid-targeted metabolomics, pathological staining, bioinformatics analysis, NEC rat model, and co-immunoprecipitation were used to explore the pathogenesis of NEC. Taxonomic characterization of the bile salt hydrolase (bsh) gene, enzyme activity assays, 16S rRNA sequencing, and organoids were used to explore the therapeutic effects of B. fragilis on NEC-related intestinal damage. Clinical samples, NEC rat models, and in vitro experiments revealed that total bile acid increased in the blood but decreased in feces. Moreover, the levels of FXR and other bile acid metabolism-related genes were abnormal, resulting in disordered bile acid metabolism in NEC. Taurochenodeoxycholic acid accelerated NEC pathogenesis and taurodeoxycholate alleviated NEC. B. fragilis displayed bsh genes and enzyme activity and alleviated intestinal damage by restoring gut microbiota dysbiosis and bile acid metabolism abnormalities by inhibiting the FXR-NLRP3 signaling pathway. Our results provide valuable insights into the therapeutic role of B. fragilis in NEC. Administering B. fragilis may substantially alleviate intestinal damage in NEC.

Characterization of Eurotium cristatum Fermented Thinned Young Apple and Mechanisms Underlying Its Alleviating Impacts on Experimental Colitis.

A hundred million tons of young apples are thinned and discarded in the orchard per year, aiming to increase the yield and quality of apples. We fermented thinned young apples using a potential probiotic fungus, Eurotium cristatum, which notably disrupted the microstructure of raw samples, as characterized by the scanning electron microscope. Fermentation substantially altered the metabolite profiles of samples, which are predicted to alleviate colitis via regulating inflammatory response and response to lipopolysaccharide by using network pharmacology analysis. In vivo, oral gavage of water extracts of E. cristatum fermented young apples (E.YAP) effectively alleviated DSS-induced colitis, restored the histopathology damage, reduced the levels of inflammatory cytokines, and promoted colonic expressions of tight junction proteins. Moreover, E.YAP ameliorated gut dysbacteriosis by increasing abundances of Lactobacillus,Blautia, Muribaculaceae, and Prevotellaceae_UCG-001 while inhibiting Turicibacter, Alistipes, and Desulfovibrio. Importantly, E.YAP increased colonic bile acids, such as CA, TCA, DCA, TUDCA, and LCA, thereby alleviating colitis via PXR/NF-κB signaling. Furthermore, a synbiotic combination with Limosilactobacillus reuteri WX-94, a probiotic strain isolated from feces of healthy individuals with anti-inflammatory properties, augmented anticolitis capacities of E.YAP. Our findings demonstrate that E.YAP could be a novel, potent, food-based anti-inflammatory prebiotic for relieving inflammatory injuries.

Dietary silymarin improves performance by altering hepatic lipid metabolism and cecal microbiota function and its metabolites in late laying hens.

BACKGROUND: Liver lipid dysregulation is one of the major factors in the decline of production performance in late-stage laying hens. Silymarin (SIL), a natural flavonolignan extracted from milk thistle, is known for its hepatoprotective and lipid-lowering properties in humans. This study evaluates whether SIL can provide similar benefits to late-stage laying hens. A total of 480 68-week-old Lohmann Pink laying hens were randomly assigned into 5 groups, each group consisting of 6 replicates with 16 hens each. The birds received a basal diet either without silymarin (control) or supplemented with silymarin at concentrations of 250, 500, 750, or 1,000 mg/kg (SIL250, SIL500, SIL750, SIL1000) over a 12-week period. RESULTS: The CON group exhibited a significant decline in laying rates from weeks 9 to 12 compared to the initial 4 weeks (P = 0.042), while SIL supplementation maintained consistent laying rates throughout the study (P > 0.05). Notably, the SIL500 and SIL750 groups showed higher average egg weight than the CON group during weeks 5 to 8 (P = 0.049). The SIL750 group had a significantly higher average daily feed intake across the study period (P < 0.05), and the SIL500 group saw a marked decrease in the feed-to-egg ratio from weeks 5 to 8 (P = 0.003). Furthermore, the SIL500 group demonstrated significant reductions in serum ALT and AST levels (P < 0.05) and a significant decrease in serum triglycerides and total cholesterol at week 12 with increasing doses of SIL (P < 0.05). SIL also positively influenced liver enzyme expression (FASN, ACC, Apo-VLDL II, FXR, and CYP7A1; P < 0.05) and altered the cecal microbiota composition, enhancing species linked to secondary bile acid synthesis. Targeted metabolomics identified 9 metabolites predominantly involved in thiamin metabolism that were significantly different in the SIL groups (P < 0.05). CONCLUSIONS: Our study demonstrated that dietary SIL supplementation could ameliorate egg production rate in late stage laying hens, mechanistically, this effect was via improving hepatic lipid metabolism and cecal microbiota function to achieve. Revealed the potentially of SIL as a feed supplementation to regulate hepatic lipid metabolism dysregulation. Overall, dietary 500 mg/kg SIL had the best effects.

Traditional medicine Xianglian pill suppresses high-fat diet-related colorectal cancer via inactivating TLR4/MyD88 by remodeling gut microbiota composition and bile acid metabolism.

ETHNOPHARMACOLOGICAL RELEVANCE: Previous studies have revealed that a high-fat diet (HFD) promotes the progression of colorectal cancer (CRC) in close association with disturbances in the intestinal flora and metabolic disorders. Xianglian pill (XLP) is a well-established traditional prescription with unique advantages in controlling intestinal flora imbalance and inflammation. However, its therapeutic effects on HFD-related CRC remain largely unknown. AIM OF THE STUDY: The primary objective of this research was to investigate the anticancer mechanism of XLP in countering HFD-related CRC. MATERIALS AND METHODS: The protective effect of XLP was evaluated using azoxymethane (AOM) and dextran sulfate sodium (DSS)-induced CRC model of mice exposed to a HFD. The degree of colorectal carcinogenesis, including body weight, colon length, and histopathology, was measured in mice treated with XLP and untreated mice. The effect of XLP on gut microbiota and its metabolites was detected using 16S rDNA and liquid chromatography/mass spectrometry analysis. Furthermore, a "pseudo-sterile" mouse model was constructed using antibiotics (Abx) to verify whether the gut microbiota and metabolites play a role in the pathogenesis of CRC. RESULTS: XLP inhibited colorectal tumorigenesis in a dose-dependent fashion. Our findings also highlighted that XLP protected the integrity of the intestinal barrier by reducing the expression of pro-inflammatory cytokines, such as IL-6 and TNF-α, as well as the infiltration of pro-inflammatory macrophages. Mechanistically, XLP inhibited the TLR4/MyD88 pathway. Notably, the XLP treatment increased the proportion of probiotics (particularly Akkermansia) and significantly reduced fecal deoxycholic acid (DCA), a microbiota-derived metabolite of bile acids (BA) closely related to Muribaculaceae. Furthermore, after Abx treatment, XLP showed no clear antitumor effects on CRC. Simultaneously, DCA-supplemented feedings promoted colorectal tumorigenesis and provoked obvious colonic inflammation, M1 macrophage infiltration, and colonic injury. In vitro, the results of RAW-264.7 macrophages and normal intestinal epithelial cells treated with DCA corroborated our in vivo findings, demonstrating consistent patterns in inflammatory responses and intestinal barrier protein expression. CONCLUSION: Our findings suggest that XLP inhibits colorectal cancer associated with HFD via inactivating TLR4/MyD88 by remodeling gut microbiota composition and BA metabolism.

Advances in the mechanism of metformin with wide-ranging effects on regulation of the intestinal microbiota.

Metformin is of great focus because of its high safety, low side effects, and various effects other than lowering blood sugar, such as anti-inflammation, anti-tumor, and anti-aging. Studies have shown that metformin has a modulating effect on the composition and function of the intestinal microbiota other than acting on the liver. However, the composition of microbiota is complex and varies to some extent between species and individuals, and the experimental design of each study is also different. Multiple factors present a major obstacle to better comprehending the effects of metformin on the gut microbiota. This paper reviews the regulatory effects of metformin on the gut microbiota, such as increasing the abundance of genus Akkermansia, enriching short-chain fatty acids (SCFAs)-producing bacterial genus, and regulating gene expression of certain genera. The intestinal microbiota is a large and vital ecosystem in the human body and is considered to be the equivalent of an "organ" of the human body, which is highly relevant to human health and disease status. There are a lot of evidences that the gut microbiota is responsible for metformin's widespread effects. However, there are only a few systematic studies on this mechanism, and the specific mechanism is still unclear. This paper aims to summarize the possible mechanism of metformin in relation to gut microbiota.

Ji-Ni-De-Xie ameliorates type 2 diabetes mellitus by modulating the bile acids metabolism and FXR/FGF15 signaling pathway.

Introduction: Ji-Ni-De-Xie (JNDX) is a traditional herbal preparation in China. It is widely used to treat type 2 diabetes mellitus (T2DM) in traditional Tibetan medicine system. However, its antidiabetic mechanisms have not been elucidated. The aim of this study is to elucidate the underlying mechanism of JNDX on bile acids (BAs) metabolism and FXR/FGF15 signaling pathway in T2DM rats. Methods: High-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-QQQ-MS) and UPLC-Q-Exactive Orbitrap MS technology were used to identify the constituents in JNDX. High-fat diet (HFD) combined with streptozotocin (45 mg∙kg-1) (STZ) was used to establish a T2DM rat model, and the levels of fasting blood-glucose (FBG), glycosylated serum protein (GSP), homeostasis model assessment of insulin resistance (HOMA-IR), LPS, TNF-α, IL-1ß, IL-6, TG, TC, LDL-C, HDL-C, and insulin sensitivity index (ISI) were measured to evaluate the anti-diabetic activity of JNDX. In addition, metagenomic analysis was performed to detect changes in gut microbiota. The metabolic profile of BAs was analyzed by HPLC-QQQ-MS. Moreover, the protein and mRNA expressions of FXR and FGF15 in the colon and the protein expressions of FGF15 and CYP7A1 in the liver of T2DM rats were measured by western blot and RT-qPCR. Results: A total of 12 constituents were identified by HPLC-QQQ-MS in JNDX. Furthermore, 45 chemical components in serum were identified from JNDX via UPLC-Q-Exactive Orbitrap MS technology, including 22 prototype components and 23 metabolites. Using a T2DM rat model, we found that JNDX (0.083, 0.165 and 0.33 g/kg) reduced the levels of FBG, GSP, HOMA-IR, LPS, TNF-α, IL-1ß, IL-6, TG, TC, and LDL-C, and increased ISI and HDL-C levels in T2DM rats. Metagenomic results demonstrated that JNDX treatment effectively improved gut microbiota dysbiosis, including altering some bacteria (e.g., Streptococcus and Bacteroides) associated with BAs metabolism. Additionally, JNDX improved BAs disorder in T2DM rats, especially significantly increasing cholic acid (CA) levels and decreasing ursodeoxycholic acid (UDCA) levels. Moreover, the protein and mRNA expressions of FXR and FGF15 of T2DM rats were significantly increased, while the expression of CYP7A1 protein in the liver was markedly inhibited by JNDX. Discussion: JNDX can effectively improve insulin resistance, hyperglycemia, hyperlipidemia, and inflammation in T2DM rats. The mechanism is related to its regulation of BAs metabolism and activation of FXR/FGF15 signaling pathway.

Exposure memory and susceptibility to ambient PM2.5: A perspective from hepatic cholesterol and bile acid metabolism.

Both epidemiological and experimental studies increasingly show that exposure to ambient fine particulate matter (PM2.5) is related to the occurrence and development of chronic diseases, such as metabolic diseases. However, whether PM2.5 has "exposure memory" and how these memories affect chronic disease development like hepatic metabolic homeostasis are unknown. Therefore, we aimed to explore the effects of exposure transition on liver cholesterol and bile acids (BAs) metabolism in mice. In this study, C57BL/6 mice were exposed to concentrated ambient PM2.5 or filtered air (FA) in a whole-body exposure facility for an initial period of 10 weeks, followed by another 8 weeks of exposure switch (PM2.5 to FA and FA to PM2.5) comparing to non-switch groups (FA to FA and PM2.5 to PM2.5), which were finally divided into four groups (FF of FA to FA, PP of PM2.5 to PM2.5, PF of PM2.5 to FA, and FP of FA to PM2.5). Our results showed no significant difference in food intake, body composition, glucose homeostasis, and lipid metabolism between FA and PM2.5 groups after the initial exposure before the exposure switch. At the end of the exposure switch, the mice switched from FA to PM2.5 exposure exhibited a high sensitivity to late-onset PM2.5 exposure, as indicated by significantly elevated hepatic cholesterol levels and disturbed BAs metabolism. However, the mice switched from PM2.5 to FA exposure retained a certain memorial effects of previous PM2.5 exposure in hepatic cholesterol levels, cholesterol metabolism, and BAs metabolism. Furthermore, 18-week PM2.5 exposure significantly increased hepatic free BAs levels, which were completely reversed by the FA exposure switch. Finally, the changes in small heterodimeric partner (SHP) and nuclear receptor subfamily 5 group A member 2 (LRH1) in response to exposure switch mechanistically explained the above alterations. Therefore, mice switching from PM2.5 exposure to FA showed only a weak memory of prior PM2.5 exposure. In contrast, the early FA caused mice to be more susceptible to subsequent PM2.5 exposure.