ABSTRACT
Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major health problem worldwide, and the strongest determinant of liver disease in children. The possible influence of high-fat/low-fiber dietary patterns with microbiota (e.g., increased Firmicutes/Bacteroidetes ratio), and ultimately with MASLD occurrence and progression has been elucidated by several association studies. The possible mechanisms through which microbes exert their detrimental effects on MASLD include gut vascular barrier damage, a shift towards non-tolerogenic immunologic environment, and the detrimental metabolic changes, including a relative reduction of propionate and butyrate in favor of acetate, endogenous ethanol production, and impairment of the unconjugated bile acid-driven FXR-mediated gut-liver axis. The impact of nutritional and probiotic interventions in children with MASLD is described.
Subject(s)
Fecal Microbiota Transplantation , Gastrointestinal Microbiome , Probiotics , Synbiotics , Humans , Probiotics/therapeutic use , Probiotics/administration & dosage , Synbiotics/administration & dosage , Child , Fecal Microbiota Transplantation/methods , Fatty Liver/therapy , Fatty Liver/microbiology , Fatty Liver/pathology , Non-alcoholic Fatty Liver Disease/microbiology , Non-alcoholic Fatty Liver Disease/therapy , Non-alcoholic Fatty Liver Disease/metabolismABSTRACT
Metabolic dysfunction-associated fatty liver disease (MAFLD) is a hepatic manifestation of the metabolic syndrome. It is one of the most common liver diseases worldwide and shows increasing prevalence rates in most countries. MAFLD is a progressive disease with the most severe cases presenting as advanced fibrosis or cirrhosis with an increased risk of hepatocellular carcinoma. Gut microbiota play a significant role in the pathogenesis and progression of MAFLD by disrupting the gut-liver axis. The mechanisms involved in maintaining gut-liver axis homeostasis are complex. One critical aspect involves preserving an appropriate intestinal barrier permeability and levels of intestinal lumen metabolites to ensure gut-liver axis functionality. An increase in intestinal barrier permeability induces metabolic endotoxemia that leads to steatohepatitis. Moreover, alterations in the absorption of various metabolites can affect liver metabolism and induce liver steatosis and fibrosis. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are a class of drugs developed for the treatment of type 2 diabetes mellitus. They are also commonly used to combat obesity and have been proven to be effective in reversing hepatic steatosis. The mechanisms reported to be involved in this effect include an improved regulation of glycemia, reduced lipid synthesis, ß-oxidation of free fatty acids, and induction of autophagy in hepatic cells. Recently, multiple peptide receptor agonists have been introduced and are expected to increase the effectiveness of the treatment. A modulation of gut microbiota has also been observed with the use of these drugs that may contribute to the amelioration of MAFLD. This review presents the current understanding of the role of the gut-liver axis in the development of MAFLD and use of members of the GLP-1 RA family as pleiotropic agents in the treatment of MAFLD.
Subject(s)
Gastrointestinal Microbiome , Glucagon-Like Peptide-1 Receptor , Liver , Humans , Glucagon-Like Peptide-1 Receptor/agonists , Glucagon-Like Peptide-1 Receptor/metabolism , Gastrointestinal Microbiome/drug effects , Liver/metabolism , Liver/drug effects , Non-alcoholic Fatty Liver Disease/drug therapy , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/microbiology , Animals , Metabolic Syndrome/drug therapy , Metabolic Syndrome/metabolism , Metabolic Syndrome/microbiology , Hypoglycemic Agents/therapeutic use , Hypoglycemic Agents/pharmacology , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/microbiology , Incretins/therapeutic use , Incretins/metabolism , Intestinal Mucosa/metabolism , Intestinal Mucosa/drug effects , Intestinal Mucosa/microbiology , Glucagon-Like Peptide-1 Receptor AgonistsABSTRACT
BACKGROUND: Although gut microbiota and serum metabolite composition have been observed to be altered in patients with non-alcoholic fatty liver disease (NAFLD), previous observational studies have demonstrated inconsistent results. As this may be influenced by factors such as confounders and reverse causality, we used Mendelian randomization to clarify the causal effect of gut microbiota and blood metabolites on NAFLD. METHODS: In this research, we performed a two-step Mendelian randomization analysis by utilizing genome-wide association study (GWAS) data obtained from MiBioGen and UK Biobank. To mitigate potential errors, we employed False Discovery Rate (FDR) correction and linkage unbalanced regression (LDSC) analysis. Sensitivity analyses including cML-MA and bidirectional Mendelian randomization were performed to ensure the robustness of the results. RESULTS: In this study, a total of nine gut microbiota and seven metabolites were found to be significantly associated with NAFLD. MR analysis of the above findings revealed a causal relationship between Ruminococcus2 and cysteine-glutathione disulfide (OR = 1.17, 95%CI = 1.006-1.369, P = 0.041), as well as 3-indoleglyoxylic acid (OR = 1.18, 95%CI = 1.011-1.370, P = 0.036). For each incremental standard deviation in Ruminococcus2 abundance, there was a corresponding 26% reduction in NAFLD risk (OR = 0.74, 95%CI = 0.61-0.89, P = 0.0012), accompanied by a 17% increase in cysteine-glutathione disulfide levels (OR = 1.17, 95%CI = 1.01-1.37, P = 0.041) and an 18% increase in 3-indoleglyoxylic acid levels (OR = 1.18, 95%CI = 0.81-1.00, P = 0.036). The proportion mediated by cysteine-glutathione disulfide is 11.2%, while the proportion mediated by 3-indoleglyoxylic acid is 7.5%. CONCLUSION: Our study suggests that increased abundance of specific gut microbiota may reduce the risk of developing NAFLD, and this relationship could potentially be mediated through blood metabolites.
Subject(s)
Gastrointestinal Microbiome , Genome-Wide Association Study , Mendelian Randomization Analysis , Non-alcoholic Fatty Liver Disease , Humans , Gastrointestinal Microbiome/genetics , Non-alcoholic Fatty Liver Disease/genetics , Non-alcoholic Fatty Liver Disease/microbiology , Female , Male , Middle AgedABSTRACT
AIMS: The incidence of nonalcoholic fatty liver disease (NAFLD) is increasing annually, leading to substantial medical and health burdens. Numerous studies have demonstrated the potential effectiveness of intestinal probiotics as a treatment strategy for NAFLD. Therefore, the objective of this study is to identify a probiotic for the treatment of NAFLD. METHODS AND RESULTS: In this study, blood and fecal samples were collected from 41 healthy volunteers and 44 patients diagnosed with NAFLD. Analysis of the 16S rDNA sequencing data and quantitative real-time PCR (RT-qPCR) revealed a significant reduction in the abundance of Coprococcus in NAFLD patients. Subsequent animal experiments demonstrated that Coprococcus was able to effectively reverse liver lipid accumulation, inflammation, and fibrosis induced by a high-fat diet (HFD) in mice. CONCLUSIONS: This study provides the first in vivo evidence that Coprococcus is a beneficial bacterium capable of preventing NAFLD and has the same probiotic effect in mice as Lactobacillus GG (LGG), a positive control. Therefore, Coprococcus has the potential to serve as a probiotic for the prevention and treatment of NAFLD in humans.
Subject(s)
Diet, High-Fat , Non-alcoholic Fatty Liver Disease , Probiotics , Animals , Non-alcoholic Fatty Liver Disease/prevention & control , Non-alcoholic Fatty Liver Disease/microbiology , Non-alcoholic Fatty Liver Disease/etiology , Diet, High-Fat/adverse effects , Probiotics/pharmacology , Probiotics/therapeutic use , Mice , Humans , Male , Mice, Inbred C57BL , Feces/microbiology , Feces/chemistry , Adult , Female , Liver/metabolism , Gastrointestinal Microbiome , Middle Aged , Disease Models, AnimalABSTRACT
Evidence has indicated that Enterococcus plays a vital role in non-alcoholic fatty liver disease (NAFLD) development. However, the microbial genetic basis and metabolic potential in the disease are yet unknown. We previously isolated a bacteria Enterococcus faecium B6 (E. faecium B6) from children with NAFLD for the first time. Here, we aim to systematically investigate the potential of strain B6 in lipogenic effects. The lipogenic effects of strain B6 were explored in vitro and in vivo. The genomic and functional characterizations were investigated by whole-genome sequencing and comparative genomic analysis. Moreover, the metabolite profiles were unraveled by an untargeted metabolomic analysis. We demonstrated that strain B6 could effectively induce lipogenic effects in the liver of mice. Strain B6 contained a circular chromosome and two circular plasmids and posed various functions. Compared to the other two probiotic strains of E. faecium, strain B6 exhibited unique functions in pathways of ABC transporters, phosphotransferase system, and amino sugar and nucleotide sugar metabolism. Moreover, strain B6 produced several metabolites, mainly enriched in the protein digestion and absorption pathway. The unique potential of strain B6 in lipogenic effects was probably associated with glycolysis, fatty acid synthesis, and glutamine and choline transport. This study pioneeringly revealed the metabolic characteristics and specific detrimental traits of strain B6. The findings provided new insights into the underlying mechanisms of E. faecium in lipogenic effects, and laid essential foundations for further understanding of E. faecium-related disease.
Subject(s)
Enterococcus faecium , Lipogenesis , Enterococcus faecium/genetics , Enterococcus faecium/metabolism , Animals , Mice , Lipogenesis/genetics , Metabolomics/methods , Non-alcoholic Fatty Liver Disease/microbiology , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/genetics , Liver/metabolism , Liver/microbiology , Male , Genome, Bacterial , Probiotics , Whole Genome Sequencing , Humans , Genomics/methods , Metabolome , Mice, Inbred C57BLABSTRACT
Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent type of liver disease worldwide. The exact pathophysiology behind MASLD remains unclear; however, it is thought that a combination of factors or "hits" act as precipitants for disease onset and progression. Abundant evidence supports the roles of diet, genes, metabolic dysregulation, and the intestinal microbiome in influencing the accumulation of lipids in hepatocytes and subsequent progression to inflammation and fibrosis. Currently, there is no cure for MASLD, but lifestyle changes have been the prevailing cornerstones of management. Research is now focusing on the intestinal microbiome as a potential therapeutic target for MASLD, with the spotlight shifting to probiotics, antibiotics, and fecal microbiota transplantation. In this review, we provide an overview of how intestinal microbiota interact with the immune system to contribute to the pathogenesis of MASLD and metabolic dysfunction-associated steatohepatitis (MASH). We also summarize key microbial taxa implicated in the disease and discuss evidence supporting microbial-targeted therapies in its management.
Subject(s)
Disease Progression , Gastrointestinal Microbiome , Humans , Fecal Microbiota Transplantation , Immune System/metabolism , Probiotics/therapeutic use , Fatty Liver/microbiology , Fatty Liver/immunology , Animals , Non-alcoholic Fatty Liver Disease/microbiology , Non-alcoholic Fatty Liver Disease/immunology , Non-alcoholic Fatty Liver Disease/metabolism , Anti-Bacterial Agents/therapeutic use , Liver/metabolismABSTRACT
Several studies show that gut microbiotas in patients with nonalcoholic fatty liver disease (NAFLD) differ from those in a healthy population, suggesting that this alteration plays a role in NAFLD pathogenesis. We investigated whether prebiotic administration affects liver fat content and/or liver-related and metabolic parameters. Patients with NAFLD and metabolic syndrome (age: 50 ± 11; 79% men) were randomized to receive either 16 g/day of prebiotic (ITFs-inulin-type fructans) (n = 8) or placebo (maltodextrin) (n = 11) for 12 weeks. Patients were instructed to maintain a stable weight throughout the study. Liver fat content (measured by H1MRS), fecal microbiota, and metabolic, inflammatory, and liver parameters were determined before and after intervention. Fecal samples from patients who received the prebiotic had an increased content of Bifidobacterium (p = 0.025), which was not observed with the placebo. However, the baseline and end-of-study liver fat contents did not change significantly in the prebiotic and placebo groups, neither did the liver function tests' metabolic and inflammatory mediators, including fibroblast growth factor-19 and lipopolysaccharide-binding protein. Body weight remained stable in both groups. These findings suggest that prebiotic treatment without weight reduction is insufficient to improve NAFLD.
Subject(s)
Feces , Gastrointestinal Microbiome , Liver , Non-alcoholic Fatty Liver Disease , Prebiotics , Humans , Non-alcoholic Fatty Liver Disease/diet therapy , Non-alcoholic Fatty Liver Disease/therapy , Non-alcoholic Fatty Liver Disease/microbiology , Prebiotics/administration & dosage , Male , Middle Aged , Female , Pilot Projects , Adult , Liver/metabolism , Feces/microbiology , Bifidobacterium , Double-Blind Method , Metabolic Syndrome/diet therapy , Metabolic Syndrome/therapyABSTRACT
Despite the observed decrease in liver fat associated with metabolic-associated fatty liver disease (MAFLD) in mice following fecal microbiota transplantation, the clinical effects and underlying mechanisms of washed microbiota transplantation (WMT), a refined method of fecal microbiota transplantation, for the treatment of MAFLD remain unclear. In this study, both patients and mice with MAFLD exhibit an altered gut microbiota composition. WMT increases the levels of beneficial bacteria, decreases the abundance of pathogenic bacteria, and reduces hepatic steatosis in MAFLD-affected patients and mice. Downregulation of the liver-homing chemokine receptor CXCR6 on ILC3s results in an atypical distribution of ILC3s in patients and mice with MAFLD, characterized by a significant reduction in ILC3s in the liver and an increase in ILC3s outside the liver. Moreover, disease severity is negatively correlated with the proportion of hepatic ILC3s. These hepatic ILC3s demonstrate a mitigating effect on hepatic steatosis through the release of IL-22. Mechanistically, WMT upregulates CXCR6 expression on ILC3s, thereby facilitating their migration to the liver of MAFLD mice via the CXCL16/CXCR6 axis, ultimately contributing to the amelioration of MAFLD. Overall, these findings highlight that WMT and targeting of liver-homing ILC3s could be promising strategies for the treatment of MAFLD.
Subject(s)
Chemokine CXCL16 , Fecal Microbiota Transplantation , Gastrointestinal Microbiome , Liver , Receptors, CXCR6 , Animals , Receptors, CXCR6/metabolism , Chemokine CXCL16/metabolism , Mice , Humans , Liver/metabolism , Liver/microbiology , Lymphocytes/immunology , Lymphocytes/metabolism , Mice, Inbred C57BL , Male , Immunity, Innate , Fatty Liver/therapy , Fatty Liver/metabolism , Fatty Liver/microbiology , Interleukin-22 , Non-alcoholic Fatty Liver Disease/therapy , Non-alcoholic Fatty Liver Disease/microbiology , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/immunology , Interleukins/metabolism , FemaleABSTRACT
Gut microbiota imbalances have a significant role in the pathogenesis of Inflammatory Bowel Disease (IBD) and Non-Alcoholic Fatty Liver Disease (NAFLD). Herein, we compared gut microbial composition in patients diagnosed with either IBD or NAFLD or a combination of both. Seventy-four participants were stratified into four groups: IBD-NAFLD, IBD-only, NAFLD-only patients, and healthy controls (CTRLs). The 16S rRNA was sequenced by Next-Generation Sequencing. Bioinformatics and statistical analysis were performed. Bacterial α-diversity showed a significant lower value when the IBD-only group was compared to the other groups and particularly against the IBD-NAFLD group. ß-diversity also showed a significant difference among groups. The higher Bacteroidetes/Firmicutes ratio was found only when comparing IBD groups and CTRLs. Comparing the IBD-only group with the IBD-NAFLD group, a decrease in differential abundance of Subdoligranulum, Parabacteroides, and Fusicatenibacter was found. Comparing the NAFLD-only with the IBD-NAFLD groups, there was a higher abundance of Alistipes, Odoribacter, Sutterella, and Lachnospira. An inverse relationship in the comparison between the IBD-only group and the other groups was shown. For the first time, the singularity of the gut microbial composition in IBD and NAFLD patients has been shown, implying a potential microbial signature mainly influenced by gut inflammation.
Subject(s)
Gastrointestinal Microbiome , Inflammatory Bowel Diseases , Metagenomics , Non-alcoholic Fatty Liver Disease , RNA, Ribosomal, 16S , Humans , Non-alcoholic Fatty Liver Disease/microbiology , Non-alcoholic Fatty Liver Disease/genetics , Gastrointestinal Microbiome/genetics , Inflammatory Bowel Diseases/microbiology , Female , Male , Middle Aged , Adult , Metagenomics/methods , RNA, Ribosomal, 16S/genetics , Bacteria/genetics , Bacteria/classification , Bacteria/isolation & purification , MetagenomeABSTRACT
Nonalcoholic fatty liver disease (NAFLD) has emerged as the most prevalent pediatric liver disorder, primarily attributed to dietary shifts in recent years. NAFLD is characterized by the accumulation of lipid species in hepatocytes, leading to liver inflammation that can progress to steatohepatitis, fibrosis, and cirrhosis. Risk factors contributing to NAFLD encompass genetic variations and metabolic disorders such as obesity, diabetes, and insulin resistance. Moreover, transgenerational influences, resulting in an imbalance of gut microbial composition, epigenetic modifications, and dysregulated hepatic immune responses in offspring, play a pivotal role in pediatric NAFLD development. Maternal nutrition shapes the profile of microbiota-derived metabolites in offspring, exerting significant influence on immune system regulation and the development of metabolic syndrome in offspring. In this review, we summarize recent evidence elucidating the intricate interplay between gut microbiota, epigenetics, and immunity in fetuses exposed to maternal nutrition, and its impact on the onset of NAFLD in offspring. Furthermore, potential therapeutic strategies targeting this network are also discussed.
Subject(s)
Epigenesis, Genetic , Gastrointestinal Microbiome , Maternal Nutritional Physiological Phenomena , Non-alcoholic Fatty Liver Disease , Prenatal Exposure Delayed Effects , Non-alcoholic Fatty Liver Disease/immunology , Non-alcoholic Fatty Liver Disease/microbiology , Non-alcoholic Fatty Liver Disease/etiology , Humans , Female , Pregnancy , Animals , Risk FactorsABSTRACT
Recent studies have highlighted the lipid-lowering ability of hawthorn ethanol extract (HEE) and the role played by gut flora in the efficacy of HEE. Our study sought to explore the effects of HEE on non-alcoholic fatty liver disease (NAFLD) in normal flora and pseudo germ-free mice. The results showed that HEE effectively diminished hepatic lipid accumulation, ameliorated liver function, reduced inflammatory cytokine levels and blood lipid profiles, and regulated blood glucose levels. HEE facilitated triglyceride breakdown, suppressed fatty acid synthesis, and enhanced intestinal health by modulating the diversity of the gut microbiota and the production of short-chain fatty acids in the gut. In addition, HEE apparently helps to increase the presence of beneficial genera of bacteria, thereby influencing the composition of the gut microbiota, and the absence of gut flora affects the efficacy of HEE. These findings reveal the potential of hawthorn for the prevention and treatment of NAFLD and provide new perspectives on the study of functional plants to improve liver health.
Subject(s)
Crataegus , Gastrointestinal Microbiome , Lipid Metabolism , Liver , Non-alcoholic Fatty Liver Disease , Plant Extracts , Gastrointestinal Microbiome/drug effects , Non-alcoholic Fatty Liver Disease/drug therapy , Non-alcoholic Fatty Liver Disease/microbiology , Plant Extracts/pharmacology , Animals , Crataegus/chemistry , Liver/metabolism , Liver/drug effects , Mice , Male , Lipid Metabolism/drug effects , Mice, Inbred C57BL , Ethanol , Disease Models, Animal , Triglycerides/blood , Triglycerides/metabolism , Cytokines/metabolism , Fatty Acids, Volatile/metabolismABSTRACT
Type 2 diabetes mellitus (T2DM), nonalcoholic fatty liver disease (NAFLD), obesity (OB) and hypertension (HT) are categorized as metabolic disorders (MDs), which develop independently without distinct borders. Herein, we examined the gut microbiota (GM) and Saururus chinensis (SC) to confirm their therapeutic effects via integrated pharmacology. The overlapping targets from the four diseases were determined to be key protein coding genes. The protein-protein interaction (PPI) networks, and the SC, GM, signalling pathway, target and metabolite (SGSTM) networks were analysed via RPackage. Additionally, molecular docking tests (MDTs) and density functional theory (DFT) analysis were conducted to determine the affinity and stability of the conformer(s). TNF was the main target in the PPI analysis, and equol derived from Lactobacillus paracasei JS1 was the most effective agent for the formation of the TNF complex. The SC agonism (PPAR signalling pathway), and antagonism (neurotrophin signalling pathway) by SC were identified as agonistic bioactives (aromadendrane, stigmasta-5,22-dien-3-ol, 3,6,6-trimethyl-3,4,5,7,8,9-hexahydro-1H-2-benzoxepine, 4α-5α-epoxycholestane and kinic acid), and antagonistic bioactives (STK734327 and piclamilast), respectively, via MDT. Finally, STK734327-MAPK1 was the most favourable conformer according to DFT. Overall, the seven bioactives from SC and equol that can be produced by Lactobacillus paracasei JS1 can exert synergistic effects on these four diseases.
Subject(s)
Diabetes Mellitus, Type 2 , Gastrointestinal Microbiome , Hypertension , Non-alcoholic Fatty Liver Disease , Obesity , Saururaceae , Gastrointestinal Microbiome/drug effects , Non-alcoholic Fatty Liver Disease/microbiology , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/drug therapy , Obesity/microbiology , Obesity/metabolism , Diabetes Mellitus, Type 2/microbiology , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/drug therapy , Hypertension/microbiology , Hypertension/metabolism , Hypertension/drug therapy , Animals , Saururaceae/chemistry , Saururaceae/metabolism , Molecular Docking Simulation , Humans , Protein Interaction MapsABSTRACT
BACKGROUND: The effective treatment of non-alcoholic fatty liver disease (NAFLD) is an unmet medical need. Qushi Huayu (QSHY) is an empirical herbal formula with promising effects in NAFLD rodent models and a connection to gut microbiota regulation. HYPOTHESIS/PURPOSE: This study aimed to evaluate the effects of QSHY in patients with NAFLD through a multicenter, randomized, double-blind, double-dummy clinical trial. STUDY DESIGN: A total of 246 eligible patients with NAFLD and liver dysfunction were evenly divided to receive either QSHY and Dangfei Liganning capsule (DFLG) simulant or QSHY simulant and DFLG (an approved proprietary Chinese medicine for NAFLD in China) for 24 weeks. The primary outcomes were changes in liver fat content, assessed using vibration-controlled transient elastography, and serum alanine aminotransferase (ALT) levels from baseline to Week 24. RESULTS: Both QSHY and DFLG led to reductions in liver fat content and liver enzyme levels post-intervention (p < 0.05). Compared to DFLG, QSHY treatment improved ALT (ß, -0.128 [95 % CI, -0.25, -0.005], p = 0.041), aspartate transaminase (ß, -0.134 [95 % CI, -0.256 to -0.012], p = 0.032), and fibrosis-4 score (ß, -0.129 [95 % CI, -0.254 to -0.003], p = 0.044) levels. QSHY markedly improved gut dysbiosis compared to DFLG, with changes in Escherichia-Shigella and Bacteroides abundance linked to its therapeutic effect on reducing ALT. Patients with a high ALT response after QSHY treatment showed superior reductions in peripheral levels of phenylalanine and tyrosine, along with an elevation in the related microbial metabolite p-Hydroxyphenylacetic acid. CONCLUSION: Our results demonstrate favorable clinical potential for QSHY in the treatment of NAFLD.
Subject(s)
Alanine Transaminase , Drugs, Chinese Herbal , Gastrointestinal Microbiome , Non-alcoholic Fatty Liver Disease , Non-alcoholic Fatty Liver Disease/drug therapy , Non-alcoholic Fatty Liver Disease/microbiology , Humans , Drugs, Chinese Herbal/pharmacology , Drugs, Chinese Herbal/therapeutic use , Male , Middle Aged , Female , Double-Blind Method , Alanine Transaminase/blood , Adult , Gastrointestinal Microbiome/drug effects , Liver/drug effects , Medicine, Chinese Traditional/methodsABSTRACT
Gut microbiota plays an essential role in nonalcoholic fatty liver disease (NAFLD). However, the contribution of individual bacterial strains and their metabolites to childhood NAFLD pathogenesis remains poorly understood. Herein, the critical bacteria in children with obesity accompanied by NAFLD were identified by microbiome analysis. Bacteria abundant in the NAFLD group were systematically assessed for their lipogenic effects. The underlying mechanisms and microbial-derived metabolites in NAFLD pathogenesis were investigated using multi-omics and LC-MS/MS analysis. The roles of the crucial metabolite in NAFLD were validated in vitro and in vivo as well as in an additional cohort. The results showed that Enterococcus spp. was enriched in children with obesity and NAFLD. The patient-derived Enterococcus faecium B6 (E. faecium B6) significantly contributed to NAFLD symptoms in mice. E. faecium B6 produced a crucial bioactive metabolite, tyramine, which probably activated PPAR-γ, leading to lipid accumulation, inflammation, and fibrosis in the liver. Moreover, these findings were successfully validated in an additional cohort. This pioneering study elucidated the important functions of cultivated E. faecium B6 and its bioactive metabolite (tyramine) in exacerbating NAFLD. These findings advance the comprehensive understanding of NAFLD pathogenesis and provide new insights for the development of microbe/metabolite-based therapeutic strategies.
Subject(s)
Enterococcus faecium , Gastrointestinal Microbiome , Non-alcoholic Fatty Liver Disease , Tyramine , Non-alcoholic Fatty Liver Disease/microbiology , Non-alcoholic Fatty Liver Disease/metabolism , Animals , Humans , Enterococcus faecium/metabolism , Mice , Child , Tyramine/metabolism , Male , Female , Mice, Inbred C57BL , Liver/metabolism , Liver/microbiology , Pediatric Obesity/microbiology , Pediatric Obesity/metabolism , Bacteria/metabolism , Bacteria/classification , Bacteria/genetics , Bacteria/isolation & purificationABSTRACT
BACKGROUND: Type 2 diabetes mellitus (T2DM) is a significant risk factor for non-alcoholic fatty liver disease (NAFLD). Increased fasting blood sugar (FBS), fasting insulin (FI), and insulin resistance (HOMA-IR) are observed in patients with NAFLD. Gut microbial modulation using prebiotics, probiotics, and synbiotics has shown promise in NAFLD treatment. This meta-umbrella study aimed to investigate the effects of gut microbial modulation on glycemic indices in patients with NAFLD and discuss potential mechanisms of action. METHODS: A systematic search was conducted in PubMed, Web of Science, Scopus, and Cochrane Library until March 2023 for meta-analyses evaluating the effects of probiotics, prebiotics, and synbiotics on patients with NAFLD. Random-effect models, sensitivity analysis, and subgroup analysis were employed. RESULTS: Gut microbial therapy significantly decreased HOMA-IR (ES: -0.41; 95%CI: -0.52, -0.31; P < 0.001) and FI (ES: -0.59; 95%CI: -0.77, -0.41; P < 0.001). However, no significant effect was observed on FBS (ES: -0.17; 95%CI: -0.36, 0.02; P = 0.082). Subgroup analysis revealed prebiotics had the most potent effect on HOMA-IR, followed by probiotics and synbiotics. For FI, synbiotics had the most substantial effect, followed by prebiotics and probiotics. CONCLUSION: Probiotics, prebiotics, and synbiotics administration significantly reduced FI and HOMA-IR, but no significant effect was observed on FBS.
Subject(s)
Gastrointestinal Microbiome , Glycemic Index , Insulin Resistance , Non-alcoholic Fatty Liver Disease , Prebiotics , Probiotics , Synbiotics , Humans , Non-alcoholic Fatty Liver Disease/therapy , Non-alcoholic Fatty Liver Disease/microbiology , Non-alcoholic Fatty Liver Disease/blood , Non-alcoholic Fatty Liver Disease/diet therapy , Prebiotics/administration & dosage , Probiotics/therapeutic use , Probiotics/administration & dosage , Synbiotics/administration & dosage , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/microbiology , Diabetes Mellitus, Type 2/therapy , Insulin/bloodABSTRACT
Synbiotics modulate the gut microbiome and contribute to the prevention of liver diseases such as metabolic-dysfunction-associated fatty liver disease (MAFLD). This study aimed to evaluate the effect of a randomized, placebo-controlled, double-blinded seven-week intervention trial on the liver metabolism in 117 metabolically healthy male participants. Anthropometric data, blood parameters, and stool samples were analyzed using linear mixed models. After seven weeks of intervention, there was a significant reduction in alanine aminotransferase (ALT) in the synbiotic group compared to the placebo group (-14.92%, CI: -26.60--3.23%, p = 0.013). A stratified analysis according to body fat percentage revealed a significant decrease in ALT (-20.70%, CI: -40.88--0.53%, p = 0.045) in participants with an elevated body fat percentage. Further, a significant change in microbiome composition (1.16, CI: 0.06-2.25, p = 0.039) in this group was found, while the microbial composition remained stable upon intervention in the group with physiological body fat. The 7-week synbiotic intervention reduced ALT levels, especially in participants with an elevated body fat percentage, possibly due to modulation of the gut microbiome. Synbiotic intake may be helpful in delaying the progression of MAFLD and could be used in addition to the recommended lifestyle modification therapy.
Subject(s)
Alanine Transaminase , Gastrointestinal Microbiome , Liver , Synbiotics , Humans , Synbiotics/administration & dosage , Male , Double-Blind Method , Adult , Liver/metabolism , Alanine Transaminase/blood , Middle Aged , Non-alcoholic Fatty Liver Disease/prevention & control , Non-alcoholic Fatty Liver Disease/microbiology , Non-alcoholic Fatty Liver Disease/therapy , Feces/microbiology , Feces/chemistryABSTRACT
Currently, Bifidobacterium, Lactobacillus, and Streptococcus thermophilus (BLS) are widely recognized as the crucially beneficial bacteria in the gut. Many preclinical and clinical studies have shown their protective effects against non-alcoholic fatty liver disease (NAFLD). However, whether gestational BLS supplementation could alleviate NAFLD in the offspring is still unknown. Kunming mice were given a high-fat diet (HFD) for 4 weeks before mating. They received BLS supplementation by gavage during pregnancy. After weaning, offspring mice were fed with a regular diet up to 5 weeks old. Gestational BLS supplementation significantly increased the abundance of Actinobacteriota, Bifidobacterium, and Faecalibaculum in the gut of dams exposed to HFD. In offspring mice exposed to maternal HFD, maternal BLS intake significantly decreased the ratio of Firmicutes to Bacteroidetes as well as the relative abundance of Prevotella and Streptococcus, but increased the relative abundance of Parabacteroides. In offspring mice, maternal BLS supplementation significantly decreased the hepatic triglyceride content and mitigated hepatic steatosis. Furthermore, maternal BLS supplementation increased the glutathione content and reduced malondialdehyde content in the liver. In addition, mRNA and protein expression levels of key rate-limiting enzymes in mitochondrial ß-oxidation (CPT1α, PPARα, and PGC1α) in the livers of offspring mice were significantly increased after gestational BLS supplementation. Thus, gestational BLS supplementation may ameliorate maternal HFD-induced steatosis and oxidative stress in the livers of offspring mice by modulating fatty acid ß-oxidation.
Subject(s)
Bifidobacterium , Diet, High-Fat , Fatty Acids , Gastrointestinal Microbiome , Lactobacillus , Oxidation-Reduction , Probiotics , Streptococcus thermophilus , Animals , Streptococcus thermophilus/metabolism , Mice , Female , Pregnancy , Probiotics/administration & dosage , Probiotics/pharmacology , Diet, High-Fat/adverse effects , Fatty Acids/metabolism , Liver/metabolism , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/microbiology , Dietary Supplements , Male , Triglycerides/metabolismABSTRACT
Despite many recent studies on non-alcoholic fatty liver disease (NAFLD) therapeutics, the optimal treatment has yet to be determined. In this unfinished project, we combined secondary metabolites (SMs) from the gut microbiota (GM) and Hordeum vulgare (HV) to investigate their combinatorial effects via network pharmacology (NP). Additionally, we analyzed GM or barley - signalling pathways - targets - metabolites (GBSTMs) in combinatorial perspectives (HV, and GM). A total of 31 key targets were analysed via a protein-protein interaction (PPI) network, and JUN was identified as the uppermost target in NAFLD. On a bubble plot, we revealed that apelin signalling pathway, which had the lowest enrichment factor antagonize NAFLD. Holistically, we scrutinized GBSTM to identify key components (GM, signalling pathways, targets, and metabolites) associated with the Apelin signalling pathway. Consequently, we found that the primary GMs (Eubacterium limosum, Eggerthella sp. SDG-2, Alistipes indistinctus YIT 12060, Odoribacter laneus YIT 12061, Paraprevotella clara YIT 11840, Paraprevotella xylaniphila YIT 11841) to ameliorate NAFLD. The molecular docking test (MDT) suggested that tryptanthrin-JUN is an agonist, conversely, dihydroglycitein-HDAC5, 1,3-diphenylpropan-2-ol-NOS1, and (10[(Acetyloxy)methyl]-9-anthryl)methyl acetate-NOS2, which are antagonistic conformers in the apelin signalling pathway. Overall, these results suggest that combination therapy could be an effective strategy for treating NAFLD.
Subject(s)
Gastrointestinal Microbiome , Hordeum , Non-alcoholic Fatty Liver Disease , Non-alcoholic Fatty Liver Disease/microbiology , Non-alcoholic Fatty Liver Disease/metabolism , Hordeum/microbiology , Hordeum/metabolism , Gastrointestinal Microbiome/drug effects , Animals , Signal Transduction/drug effects , Mice , Protein Interaction Maps , HumansABSTRACT
Ursodeoxycholic acid (UDCA) is a hydrophilic bile acid commonly used for treating cholestatic liver disease. However, its efficacy on non-alcoholic steatohepatitis (NASH) was controversial. This study aimed to investigate the impact of a high dosage of UDCA on a mouse model of NASH. Forty 6-week-old mice were fed a high-fat high-cholesterol (HFHC) diet for 12 weeks to establish a mouse model of NASH, and then divided into four groups: two groups transitioned to a normal diet, and the other two groups maintained the HFHC diet. Each group was administered a daily dosage of 300â¯mg/kg of UDCA or saline for a period of 8 weeks. The 16â¯s ribosomal RNA genes extracted from mice fecal pellets were sequenced using next-generation sequencing techniques. Serum bile acid profiles were quantified using liquid chromatography electrospray ionization tandem mass spectrometry method. The results showed that UDCA treatment ameliorated liver inflammation, without affecting liver fibrosis. UDCA treatment reduced the relative abundance of the genera Bacteroides, Parabacteroides, and Intestinimonas, whereas increased the relative abundance of the genera norank_f_Muribaculaceae and Parasutterella in the HFHC-maintaining groups. The serum levels of total bile acids and total primary bile acids increased, whereas those of endogenous primary bile acids decreased after UDCA treatment. Correlation analysis showed that primary bile acids were negatively correlated with the genera norank_f_Christensenellaceae and unclassified_f_Ruminococcaceae. In conclusion, a high dosage of UDCA can alleviate liver inflammation, probably by modifying the composition of gut microbiota and serum bile acid profiles in NASH mice.
Subject(s)
Bile Acids and Salts , Disease Models, Animal , Gastrointestinal Microbiome , Mice, Inbred C57BL , Non-alcoholic Fatty Liver Disease , Ursodeoxycholic Acid , Animals , Ursodeoxycholic Acid/pharmacology , Ursodeoxycholic Acid/administration & dosage , Non-alcoholic Fatty Liver Disease/drug therapy , Non-alcoholic Fatty Liver Disease/microbiology , Non-alcoholic Fatty Liver Disease/pathology , Gastrointestinal Microbiome/drug effects , Bile Acids and Salts/metabolism , Bile Acids and Salts/blood , Male , Mice , Diet, High-Fat , Liver/drug effects , Liver/metabolism , Liver/pathologyABSTRACT
The gastrointestinal tract is inhabited by the gut microbiota. The main phyla are Firmicutes and Bacteroidetes. In non-alcoholic fatty liver disease, now renamed metabolic dysfunction-associated fatty liver disease (MAFLD), an alteration in Firmicutes and Bacteroidetes abundance promotes its pathogenesis and evolution into non-alcoholic steatohepatitis, liver cirrhosis, and hepatocellular carcinoma. For this reason, early treatment is necessary to counteract its progression. The aim of the present narrative review is to evaluate the different therapeutic approaches to MAFLD. The most important treatment for MAFLD is lifestyle changes. In this regard, the Mediterranean diet could be considered the gold standard in the prevention and treatment of MAFLD. In contrast, a Western diet should be discouraged. Probiotics and fecal microbiota transplantation seem to be valid, safe, and effective alternatives for MAFLD treatment. However, more studies with a longer follow-up and with a larger cohort of patients are needed to underline the more effective approaches to contrasting MAFLD.