The Association of Gut Microbiota with Nonalcoholic Steatohepatitis in Thais

Therapeutic Role of Probiotics Against Environmental-Induced Hepatotoxicity: Mechanisms, Clinical Perspectives, Limitations, and Future

Hepatotoxicity is one of the biggest health challenges, particularly in the context of liver diseases, often aggravated by gut microbiota dysbiosis. The gut-liver axis has been regarded as a key idea in liver health. It indicates that changes in gut flora caused by various hepatotoxicants, including alcoholism, acetaminophen, carbon tetrachloride, and thioacetamide, can affect the balance of the gut's microflora, which may lead to increased dysbiosis and intestinal permeability. As a result, bacterial endotoxins would eventually enter the bloodstream and liver, causing hepatotoxicity and inducing inflammatory reactions. Many treatments, including liver transplantation and modern drugs, can be used to address these issues. However, because of the many side effects of these approaches, scientists and medical experts are still hoping for a therapeutic approach with fewer side effects and more positive results. Thus, probiotics have become well-known as an adjunctive strategy for managing, preventing, or reducing hepatotoxicity in treating liver injury. By altering the gut microbiota, probiotics offer a secure, non-invasive, and economical way to improve liver health in the treatment of hepatotoxicity. Through various mechanisms such as regulation of gut microbiota, reduction of pathogenic overgrowth, suppression of inflammatory mediators, modification of hepatic lipid metabolism, improvement in the performance of the epithelial barrier of the gut, antioxidative effects, and modulation of mucosal immunity, probiotics play their role in the treatment and prevention of hepatotoxicity. This review highlights the mechanistic effects of probiotics in environmental toxicants-induced hepatotoxicity and current findings on this therapeutic approach's experimental and clinical trials.

The role of gut microbiota in obesity severity and metabolic risk in pediatric populations

BACKGROUND AND AIMS

Childhood obesity is a considerable public health issue. Recent research has shown that alterations in gut microbiota can have an impact on developing obesity and other metabolic health problems in children. This study aimed to investigate whether the characteristics of gut microbiota in obese children and adolescents are associated with the severity of obesity and any metabolic complications.

METHODS AND RESULTS

During May 2022 to May 2023, a total of 56 children and adolescents with obesity, aged 6-18 years, were recruited at Thammasat Hospital, situated in provincial Pathumthani in central Thailand. Participants were allocated into two groups, characterized by the severity of their obesity. Demographic data, body composition, along with resting energy expenditures were determined. Serum samples were collected for the metabolic profile and inflammatory markers. Fecal samples were obtained for gut microbiota analysis via 16S rRNA Illumina. The obese group exhibited notably greater relative abundance of Actinobacteriota in comparison to the severely obese group, along with a lower abundance of Bacteroidota. There were no statistically significant differences in the relative abundance of Firmicutes and the Firmicutes to Bacteroidota ratio between the two cohorts. Bacteroidota positively correlated with FMI, while Actinobacteriota showed a negative correlation with FMI.

CONCLUSION

The data gathered from this study illustrated that children and adolescents with obesity and severe obesity in Thailand showed differences in the relative abundance of Actinobacteriota and Bacteroidota. Certain microbiome taxa showed correlations with various body and metabolic parameters.

Deciphering the Gut–Liver Axis: A Comprehensive Scientific Review of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has emerged as a significant global health issue. The condition is closely linked to metabolic dysfunctions such as obesity and type 2 diabetes. The gut–liver axis, a bidirectional communication pathway between the liver and the gut, plays a crucial role in the pathogenesis of NAFLD. This review delves into the mechanisms underlying the gut–liver axis, exploring the influence of gut microbiota, intestinal permeability, and inflammatory pathways. This review also explores the potential therapeutic strategies centered on modulating gut microbiota such as fecal microbiota transplantation; phage therapy; and the use of specific probiotics, prebiotics, and postbiotics in managing NAFLD. By understanding these interactions, we can better comprehend the development and advancement of NAFLD and identify potential therapeutic targets.

Melatonin Prevents Thioacetamide-Induced Gut Leakiness and Liver Fibrosis Through the Gut-Liver Axis via Modulating Sirt1-Related Deacetylation of Gut Junctional Complex and Hepatic Proteins

Intestinal barrier dysfunction with high serum endotoxin is common in patients with liver fibrosis, but the mechanisms underlying liver fibrosis remain unclear. Melatonin is a well-recognized antioxidant and an anti-inflammatory agent that benefits multiple organs. However, the beneficial effects of melatonin on gut leakiness-associated liver fibrosis have not been systemically studied. Here, we investigated the protective mechanisms of melatonin against thioacetamide (TAA)-induced gut barrier dysfunction and hepatic fibrosis by focusing on posttranslational protein modifications through the gut-liver axis. Our results showed that gut leakiness markers, including decreased gut tight/adherens junction proteins (TJ/AJs) with increased intestinal deformation, apoptosis, and serum endotoxin, were observed early at 1 week after TAA exposure. Liver injury, apoptosis, and fibrosis were prominent at 2 and 4 weeks. Mechanistically, we found that gut TJ/AJs were hyper-acetylated, followed by ubiquitin-dependent proteolysis, leading to their degradation and gut leakiness. Gut dysbiosis, hepatic protein hyper-acetylation, and SIRT1 downregulation were also observed. Consistently, intestinal Sirt1 deficiency greatly enhanced protein hyper-acetylation, gut leakiness, endotoxemia, and liver fibrosis. Pretreatment with melatonin prevented or improved all these changes in both the gut and liver. Furthermore, melatonin blunted protein acetylation and injury in TAA-exposed T84 human intestinal and AML12 mouse liver cells. Overall, this study demonstrated novel mechanisms by which melatonin prevents gut leakiness and liver fibrosis through the gut-liver axis by attenuating the acetylation of intestinal and hepatic proteins. Thus, melatonin consumption can become a potentially safe supplement for liver fibrosis patients by preventing protein hyper-acetylation and gut leakiness.

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

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

Changes in the intestinal microbiota of individuals with non-alcoholic fatty liver disease based on sequencing: An updated systematic review and meta-analysis

BACKGROUND

Alterations in the composition and abundance of the intestinal microbiota occur in non-alcoholic fatty liver disease (NAFLD). However, the results are inconsistent because of differences in the study design, subject area, and sequencing methodology. In this study, we compared the diversity and abundance of the intestinal microbiota of patients with NAFLD and healthy individuals through a systematic review and meta-analysis.

METHODS

Three databases (PubMed, EMBASE, and Cochrane Library) were searched from their inception to March 20, 2023. A meta-analysis was performed using Stata software to analyze variations in the richness and abundance of the intestinal microbiota in patients with NAFLD. The Newcastle-Ottawa Quality Assessment Scale (NOS) was used for quality assessment.

RESULTS

A total of 28 articles were included. Shannon diversity was reduced in patients with NAFLD (SMD = -0.24 (95% CI -0.43-0.05, I2 = 71.7%). The relative abundance of Ruminococcus, Faecalibacterium, and Coprococcus all decreased, with total SMDs of -0.96 (95% CI -1.29 to -0.63, I2 = 4.8%), -1.13 (95% CI -2.07 to -0.19, I2 = 80.5%), and -1.66 (95% CI -3.04 to -0.28, I2 = 91.5%). Escherichia was increased in individuals with NAFLD (SMD = 1.78, 95% CI 0.12 to 3.45, I2 = 94.4%).

CONCLUSION

Increasing the species diversity and altering the abundance of specific gut microbiota, including Coprococcus, Faecalibacterium, Ruminococcus, and Escherichia, may be beneficial for improving NAFLD.

Gut microbiota and metabolic biomarkers in metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD), a replacement of the nomenclature employed for NAFLD, is the most prevalent chronic liver disease worldwide. Despite its high global prevalence, NAFLD is often under-recognized due to the absence of reliable noninvasive biomarkers for diagnosis and staging. Growing evidence suggests that the gut microbiome plays a significant role in the occurrence and progression of NAFLD by causing immune dysregulation and metabolic alterations due to gut dysbiosis. The rapid advancement of sequencing tools and metabolomics has enabled the identification of alterations in microbiome signatures and gut microbiota-derived metabolite profiles in numerous clinical studies related to NAFLD. Overall, these studies have shown a decrease in α-diversity and changes in gut microbiota abundance, characterized by increased levels of Escherichia and Prevotella, and decreased levels of Akkermansia muciniphila and Faecalibacterium in patients with NAFLD. Furthermore, bile acids, short-chain fatty acids, trimethylamine N-oxide, and tryptophan metabolites are believed to be closely associated with the onset and progression of NAFLD. In this review, we provide novel insights into the vital role of gut microbiome in the pathogenesis of NAFLD. Specifically, we summarize the major classes of gut microbiota and metabolic biomarkers in NAFLD, thereby highlighting the links between specific bacterial species and certain gut microbiota-derived metabolites in patients with NAFLD.

Investigating causal associations among gut microbiota, metabolites, and psoriatic arthritis: a Mendelian randomization study

Background

Currently, there has been observed a significant alteration in the composition of the gut microbiome (GM) and serum metabolites in patients with psoriatic arthritis (PsA) compared to healthy individuals. However, previous observational studies have shown inconsistent results regarding the alteration of gut microbiota/metabolites. In order to shed light on this matter, we utilized Mendelian randomization to determine the causal effect of GM/metabolites on PsA.

Methods

We retrieved summary-level data of GM taxa/metabolites and PsA from publicly available GWAS statistics. Causal relationships between GM/metabolites and PsA were determined using a two-sample MR analysis, with the IVW approach serving as the primary analysis method. To ensure the robustness of our findings, we conducted sensitivity analyses, multivariable MR analysis (MVMR), and additional analysis including replication verification analysis, LDSC regression, and Steiger test analysis. Furthermore, we investigated reverse causality through a reverse MR analysis. Finally, we conducted an analysis of expression quantitative trait loci (eQTLs) involved in the metabolic pathway to explore potential molecular mechanisms of metabolism.

Results

Our findings reveal that eight GM taxa and twenty-three serum metabolites are causally related to PsA (P < 0.05). Notably, a higher relative abundance of Family Rikenellaceae (ORIVW: 0.622, 95% CI: 0.438-0.883, FDR = 0.045) and elevated serum levels of X-11538 (ORIVW: 0.442, 95% CI: 0.250-0.781, FDR = 0.046) maintain significant causal associations with a reduced risk of PsA, even after adjusting for multiple testing correction and conducting MVMR analysis. These findings suggest that Family Rikenellaceae and X-11538 may have protective effects against PsA. Our sensitivity analysis and additional analysis revealed no significant horizontal pleiotropy, reverse causality, or heterogeneity. The functional enrichment analysis revealed that the eQTLs examined were primarily associated with glycerolipid metabolism and the expression of key metabolic factors influenced by bacterial infections (Vibrio cholerae and Helicobacter pylori) as well as the mTOR signaling pathway.

Conclusion

In conclusion, our study demonstrates that Family Rikenellaceae and X-11538 exhibit a strong and negative causal relationship with PsA. These particular GM taxa and metabolites have the potential to serve as innovative biomarkers, offering valuable insights into the treatment and prevention of PsA. Moreover, bacterial infections and mTOR-mediated activation of metabolic factors may play an important role in this process.

Composition of gut microbiota and non-alcoholic fatty liver disease: A systematic review and meta-analysis

The present systematic review and meta-analysis aimed to summarize the associations between gut microbiota composition and non-alcoholic fatty liver disease. To compare the differences between individuals with or without NAFLD, the standardized mean difference and 95% confidence interval were computed for each α-diversity index and relative abundance of gut microbes. The β-diversity indices were summarized in a qualitative manner. A total of 54 studies with 8894 participants were included. Overall, patients with NAFLD had moderate reduction in α-diversity indices including Shannon (SMD = -0.36, 95% CI = [-0.53, -0.19], p < 0.001) and Chao 1 (SMD = -0.42, 95% CI = [-0.68, -0.17], p = 0.001), but no significant differences were found for Simpson, observed species, phylogenetic diversity, richness, abundance-based coverage estimator, and evenness (p ranged from 0.081 to 0.953). Over 75% of the included studies reported significant differences in β-diversity. Although there was substantial interstudy heterogeneity, especially for analyses at the phylum, class, and family levels, the majority of the included studies showed alterations in the depletion of anti-inflammatory microbes (i.e., Ruminococcaceae and Coprococcus) and the enrichment of proinflammatory microbes (i.e., Fusobacterium and Escherichia) in patients with NAFLD. Perturbations in gut microbiota were associated with NAFLD, commonly reflected by a reduction in beneficial species and an increase in the pathogenic species.

Effect of natural polysaccharides on alcoholic liver disease: A review

In this study, we systematically collected relevant literature in the past five years on the intervention of natural polysaccharides in alcoholic liver disease (ALD) and reviewed the pharmacological activities and potential mechanisms of action. Natural polysaccharides are effective in preventing liver tissue degeneration, inhibiting the alcohol-induced expression of inflammatory factors, inactivation of antioxidant enzymes, and abnormal hepatic lipid deposition. Natural polysaccharides regulate the expression of proteins, such as tight junction proteins, production of small molecule metabolites, and balance of intestinal flora in the intestinal tract to alleviate ALD. Natural polysaccharides also exert therapeutic effects by modulating inflammatory, oxidative, lipid metabolism, and other pathways in the liver. Natural polysaccharides also inhibit alcohol-induced intestinal abnormalities by regulating intestinal flora and feeding back into the liver via the gut-liver axis. However, existing research on natural polysaccharides has many shortcomings: for example, most of the natural polysaccharides for testing are total polysaccharides or crude polysaccharides, progress in research on in vivo metabolic processes and mechanisms is slow, and the degree of industrialisation is insufficient. Finally, we discuss the difficulties in studying natural polysaccharides and future directions to provide a theoretical basis for their development and application.

Gut Microbiota Patterns in Patients with Non-Alcoholic Fatty Liver Disease: A Comprehensive Assessment Using Three Analysis Methods

Non-alcoholic fatty liver disease (NAFLD) is considered the most common chronic liver disease worldwide, affecting nearly 25% of the global adult population. Increasing evidence suggests that functional and compositional changes in the gut microbiota may contribute to the development and promote the progression of NAFLD. 16S rRNA gene next-generation sequencing is widely used to determine specific features of the NAFLD microbiome, but a complex system such as the gut microbiota requires a comprehensive approach. We used three different approaches: MALDI-TOF-MS of bacterial cultures, qPCR, and 16S NGS sequencing, as well as a wide variety of statistical methods to assess the differences in gut microbiota composition between NAFLD patients without significant fibrosis and the control group. The listed methods showed enrichment in Collinsella sp. and Oscillospiraceae for the control samples and enrichment in Lachnospiraceae (and in particular Dorea sp.) and Veillonellaceae in NAFLD. The families, Bifidobacteriaceae, Lactobacillaceae, and Enterococcaceae (particularly Enterococcus faecium and Enterococcus faecalis), were also found to be important taxa for NAFLD microbiome evaluation. Considering individual method observations, an increase in Candida krusei and a decrease in Bacteroides uniformis for NAFLD patients were detected using MALDI-TOF-MS. An increase in Gracilibacteraceae, Chitinophagaceae, Pirellulaceae, Erysipelatoclostridiaceae, Muribaculaceae, and Comamonadaceae, and a decrease in Acidaminococcaceae in NAFLD were observed with 16S NGS, and enrichment in Fusobacterium nucleatum was shown using qPCR analysis. These findings confirm that NAFLD is associated with changes in gut microbiota composition. Further investigations are required to determine the cause-and-effect relationships and the impact of microbiota-derived compounds on the development and progression of NAFLD.

Probiotics, prebiotics, and synbiotics in nonalcoholic fatty liver disease and alcohol-associated liver disease

The use of probiotics, prebiotics, and synbiotics has become an important therapy in numerous gastrointestinal diseases in recent years. Modifying the gut microbiota, this therapeutic approach helps to restore a healthy microbiome. Nonalcoholic fatty liver disease and alcohol-associated liver disease are among the leading causes of chronic liver disease worldwide. A disrupted intestinal barrier, microbial translocation, and an altered gut microbiome metabolism, or metabolome, are crucial in the pathogenesis of these chronic liver diseases. As pro-, pre-, and synbiotics modulate these targets, they were identified as possible new treatment options for liver disease. In this review, we highlight the current findings on clinical and mechanistic effects of this therapeutic approach in nonalcoholic fatty liver disease and alcohol-associated liver disease.

Current, emerging, and potential therapies for non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) has been identified as the most common chronic liver disease worldwide, with a growing incidence. NAFLD is considered the hepatic manifestation of a metabolic syndrome that emerges from multiple factors (e.g., oxidative stress, metabolic disorders, endoplasmic reticulum stress, cell death, and inflammation). Non-alcoholic steatohepatitis (NASH), an advanced form of NAFLD, has been reported to be a leading cause of cirrhosis and hepatic carcinoma, and it is progressing rapidly. Since there is no approved pharmacotherapy for NASH, a considerable number of therapeutic targets have emerged with the deepening of the research on NASH pathogenesis. In this study, the therapeutic potential and properties of regulating metabolism, the gut microbiome, antioxidant, microRNA, inhibiting apoptosis, targeting ferroptosis, and stem cell-based therapy in NASH are reviewed and evaluated. Since the single-drug treatment of NASH is affected by individual heterogeneous responses and side effects, it is imperative to precisely carry out targeted therapy with low toxicity. Lastly, targeted therapeutic agent delivery based on exosomes is proposed in this study, such that drugs with different mechanisms can be incorporated to generate high-efficiency and low-toxicity individualized medicine.

Nutritional implications in the mechanistic link between the intestinal microbiome, renin-angiotensin system, and the development of obesity and metabolic syndrome

Obesity and metabolic disorders represent a significant global health problem and the gut microbiota plays an important role in modulating systemic homeostasis. Recent evidence shows that microbiota and its signaling pathways may affect the whole metabolism and the Renin-Angiotensin System (RAS), which in turn seems to modify microbiota. The present review aimed to investigate nutritional implications in the mechanistic link between the intestinal microbiome, renin-angiotensin system, and the development of obesity and metabolic syndrome components. A description of metabolic changes was obtained based on relevant scientific literature. The molecular and physiological mechanisms that impact the human microbiome were addressed, including the gut microbiota associated with obesity, diabetes, and hepatic steatosis. The RAS interaction signaling and modulation were analyzed. Strategies including the use of prebiotics, symbiotics, probiotics, and biotechnology may affect the gut microbiota and its impact on human health.

Polysaccharides from Ostrea rivularis rebuild the balance of gut microbiota to ameliorate non-alcoholic fatty liver disease in ApoE-/- mice

The purpose of this study was to investigate the preventive effects of polysaccharide from Ostrea rivularis (ORP) on high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) in mice and the underlying mechanism. The results showed that NAFLD model group mice had significant fatty liver lesions. ORP could significantly reduce TC, TG and LDL level, and increase HDL level in serum of HFD mice. Besides, it could also reduce the contents of serum AST and ALT and alleviate pathological changes of fatty liver disease. ORP could also enhance the intestinal barrier function. 16sRNA analysis showed that ORP could reduce the abundance of Firmicutes and Proteobacteria and the ratio of Firmicutes/ Bacteroidetes at the phylum level. These results suggested that ORP could regulate the composition of gut microbiota in NAFLD mice, enhance intestinal barrier function, reduce intestinal permeability, and finally delay the progress and reduce the occurrence of NAFLD. In brief, ORP is an ideal polysaccharide for prevention and treatment of NAFLD, which can be developed as functional food or candidate drugs.

Key Stratification of Microbiota Taxa and Metabolites in the Host Metabolic Health-Disease Balance

Human gut microbiota seems to drive the interaction with host metabolism through microbial metabolites, enzymes, and bioactive compounds. These components determine the host health-disease balance. Recent metabolomics and combined metabolome-microbiome studies have helped to elucidate how these substances could differentially affect the individual host pathophysiology according to several factors and cumulative exposures, such as obesogenic xenobiotics. The present work aims to investigate and interpret newly compiled data from metabolomics and microbiota composition studies, comparing controls with patients suffering from metabolic-related diseases (diabetes, obesity, metabolic syndrome, liver and cardiovascular diseases, etc.). The results showed, first, a differential composition of the most represented genera in healthy individuals compared to patients with metabolic diseases. Second, the analysis of the metabolite counts exhibited a differential composition of bacterial genera in disease compared to health status. Third, qualitative metabolite analysis revealed relevant information about the chemical nature of metabolites related to disease and/or health status. Key microbial genera were commonly considered overrepresented in healthy individuals together with specific metabolites, e.g., Faecalibacterium and phosphatidylethanolamine; and the opposite, Escherichia and Phosphatidic Acid, which is converted into the intermediate Cytidine Diphosphate Diacylglycerol-diacylglycerol (CDP-DAG), were overrepresented in metabolic-related disease patients. However, it was not possible to associate most specific microbiota taxa and metabolites according to their increased and decreased profiles analyzed with health or disease. Interestingly, positive association of essential amino acids with the genera Bacteroides were observed in a cluster related to health, and conversely, benzene derivatives and lipidic metabolites were related to the genera Clostridium, Roseburia, Blautia, and Oscillibacter in a disease cluster. More studies are needed to elucidate the microbiota species and their corresponding metabolites that are key in promoting health or disease status. Moreover, we propose that greater attention should be paid to biliary acids and to microbiota-liver cometabolites and its detoxification enzymes and pathways.

Diet Quality and Liver Health in People Living with HIV in the MASH Cohort: A Multi-Omic Analysis of the Fecal Microbiome and Metabolome

The gut-liver axis has been recognized as a potential pathway in which dietary factors may contribute to liver disease in people living with HIV (PLWH). The objective of this study was to explore associations between dietary quality, the fecal microbiome, the metabolome, and liver health in PLWH from the Miami Adult Studies on HIV (MASH) cohort. We performed a cross-sectional analysis of 50 PLWH from the MASH cohort and utilized the USDA Healthy Eating Index (HEI)-2015 to measure diet quality. A Fibrosis-4 Index (FIB-4) score < 1.45 was used as a strong indication that advanced liver fibrosis was not present. Stool samples and fasting blood plasma samples were collected. Bacterial composition was characterized using 16S rRNA sequencing. Metabolomics in plasma were determined using gas and liquid chromatography/mass spectrometry. Statistical analyses included biomarker identification using linear discriminant analysis effect size. Compared to participants with FIB-4 ≥ 1.45, participants with FIB-4 < 1.45 had higher intake of dairy (p = 0.006). Fibrosis-4 Index score was inversely correlated with seafood and plant protein HEI component score (r = -0.320, p = 0.022). The relative abundances of butyrate-producing taxa Ruminococcaceae, Roseburia, and Lachnospiraceae were higher in participants with FIB-4 < 1.45. Participants with FIB-4 < 1.45 also had higher levels of caffeine (p = 0.045) and related metabolites such as trigonelline (p = 0.008) and 1-methylurate (p = 0.023). Dietary components appear to be associated with the fecal microbiome and metabolome, and liver health in PLWH. Future studies should investigate whether targeting specific dietary components may reduce liver-related morbidity and mortality in PLWH.

Constitution of mucosa‐associated microbiota in the lower digestive tract does not change in early stage of non‐alcoholic fatty liver disease with fecal dysbiosis

Background and Aim

Methods

Results

Conclusion

Metagenomic identification of gut microbiota distribution on the colonic mucosal biopsy samples in patients with non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is known to be the most common liver disease in the world, and there are currently no approved pharmacological treatments to prevent or treat this condition. In addition to being associated with an increased risk of hepatocellular carcinoma and cirrhosis, NAFLD has now become the leading cause of liver failure-associated transplantation. The 16S rRNA gene which conserved regions can serve as universal primer binding sites for PCR amplification of gene fragments, while hypervariable regions contain significant sequence diversity useful for prokaryotic identification purposes. 16S rRNA gene sequences can be use by researchers to identify prokaryotic taxonomy found in clinical samples. As a result of increasing microbiota studies with developing technological developments, the role of intestinal microbiota in the pathogenesis of NAFLD is revealed in an important way. In this study, it was aimed to determine the clinical prognostic importance of gut microbiota in the pathogenesis of NAFLD and to determine the microbial composition with intestinal mucosal biopsy samples in NAFLD patients.

MATERIAL AND METHOD

We included 20 patients diagnosed with NAFLD as a result of liver function tests, histological, ultrasonographic, biopsy evidence and 20 normal control groups created under exclusion criteria in this study. The healthy control group of the same age and gender as the patients were determined to be equal, and the age, gender, BMI, insulin resistance, AST, ALT levels of the individuals were recorded for analysis. İntestinal mucosal biopsy samples were taken from the individuals included in the study under sterile conditions. Microbial results were obtained as a result of 16S rRNA amplicon metagenomic processes. The region of approximately 1500 bp covering the V1-V9 region of the 16S rRNA gene was targeted to detect microbial diversity. The amplified regions were sequenced using next-generation sequencing. Operational Taxonomic Unit (OTU) value was obtained with bioinformatics software with the obtained sequence data. The analysis of the recorded parameters was done with the SPSS.19 statistical program.

RESULTS

In the designed study, 16 phyla, 28 class, 56 order, 128 family, 415 genera, 1041 species microorganisms were analyzed taxonomically in a total of 40 individuals. In our study, Intestinal microbial diversity is lower in NAFLD patients compared to control group individuals. In addition, gram-negative bacteria were found to be more dominant in NAFLD patients. As a phylum, Proteobacteria increased in NAFLD group, Bacteroidetes and Actinobacteria in control group, while Firmicutes had equal distribution in both groups. BMI OR = 6.37, 95 %CI (0.39-0.40) p value was 0.001 in laboratory data, whereas Proteobacteria OR = 1.754, 95% CI (0.901-3.416), p value 0.05 in microbial profile.

CONCLUSION

The 16S rRNA metagenomic study of intestinal microbiota using colonic mucosal biopsy samples in NAFLD disease was the first study in the Turkish population, and important data were obtained for other studies. In the data obtained, we think Proteobacteria, Ruminococcaceae, Escherichia coli and Bacilli are very important in both diagnostic and treatment options as a microbial profile in NAFLD.

Alteration of gut microbiota during narrowband ultraviolet B therapy: A preliminary study

BACKGROUND

Gut microbiome dysbiosis is associated with psoriasis development. A relationship between gut microbiota and psoriasis treatment response has been reported. No study has reported the effect of narrowband ultraviolet B (NBUVB) therapy, a standard treatment of psoriasis, on gut microbiota.

QUESTION ADDRESSED

This study aimed to evaluate gut microbiota change during NBUVB therapy.

EXPERIMENTAL DESIGN

Stool samples from 22 participants, including 13 patients with chronic plaque psoriasis and nine healthy controls, were recruited. Fecal microbiota composition was analyzed using 16S rRNA sequencing before and after NBUVB therapy. Serum 25-OH Vitamin D of patients with psoriasis was evaluated simultaneously.

RESULTS

The most abundant phyla of gut microbiota in patients with psoriasis were Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria in all participants. Bilophila, Paraprevotella, Alistipes, Sutterella, Romboutsia, Clostridium sensu stricto, and Agathobacter are significantly more enriched in healthy controls. Lactobacillales and Ruminococus torques appeared more enriched after NBUVB treatment in responders but not non-responders. Serum Vitamin D levels significantly increased after NBUVB treatment.

CONCLUSIONS&PERSPECTIVE

The present study revealed that gut microbiota altered after NBUVB treatment. The change might be treatment-specific and influence the treatment response.

THC and CBD affect metabolic syndrome parameters including microbiome in mice fed high fat-cholesterol diet

Background

Nonalcoholic fatty liver disease (NAFLD) is associated with metabolic syndrome, which often includes obesity, diabetes, and dyslipidemia. Several studies in mice and humans have implicated the involvement of the gut microbiome in NAFLD. While cannabis and its phytocannabinoids may potentially be beneficial for treating metabolic disorders such as NAFLD, their effects on liver diseases and gut microbiota profile have yet to be addressed. In this study, we evaluated the therapeutic effects of the two major cannabinoids, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), on NAFLD progression.

Methods

NAFLD was induced by feeding mice a high fat-cholesterol diet (HFCD) for 6 weeks. During this period, the individual cannabinoids, THC or CBD, were added to the experimental diets at a concentration of 2.5 or 2.39 mg/kg. Profile of lipids, liver enzymes, glucose tolerance, and gene expression related to carbohydrate lipids metabolism and liver inflammation was analyzed. The effect of THC or CBD on microbiota composition in the gut was evaluated.

Results

While not alleviating hepatic steatosis, THC or CBD treatment influenced a number of parameters in the HFCD mouse model. CBD increased food intake, improved glucose tolerance, reduced some of the inflammatory response including TNFa and iNOS, and partially mitigated the microbiome dysbiosis observed in the HFCD fed mice. THC produced a much weaker response, only slightly reducing inflammatory-related gene expression and microbiome dysbiosis.

Conclusions

The results of this study indicate the potential therapeutic effects of individual phytocannabinoids are different from the effects of the cannabis plant possessing a mixture of compounds. While CBD may help ameliorate symptoms of NAFLD, THC alone may not be as effective. This disparity can putatively be explained based on changes in the gut microbiota.

Gut–Skin Axis: Unravelling the Connection between the Gut Microbiome and Psoriasis

Evidence has shown that gut microbiome plays a role in modulating the development of diseases beyond the gastrointestinal tract, including skin disorders such as psoriasis. The gut–skin axis refers to the bidirectional relationship between the gut microbiome and skin health. This is regulated through several mechanisms such as inflammatory mediators and the immune system. Dysregulation of microbiota has been seen in numerous inflammatory skin conditions such as atopic dermatitis, rosacea, and psoriasis. Understanding how gut microbiome are involved in regulating skin health may lead to development of novel therapies for these skin disorders through microbiome modulation, in particularly psoriasis. In this review, we will compare the microbiota between psoriasis patients and healthy control, explain the concept of gut–skin axis and the effects of gut dysbiosis on skin physiology. We will also review the current evidence on modulating gut microbiome using probiotics in psoriasis.

Association of dietary patterns with gut microbiota in kidney stone and non-kidney stone individuals

The dietary patterns are closely associated with gut microbiota, which has been proved associated with kidney stones. To assess the association among the dietary patterns, gut microbiota, and kidney stones, patients with calcium oxalate stones and participants without kidney stones were recruited in West China Hospital and were divided into the low nephrolithiasis risk (LNR) and high nephrolithiasis risk (HNR) dietary pattern group based on the results of food frequency questionnaires. The genomic DNA of the fecal samples were extracted for 16S ribosomal RNA gene sequencing. The non-kidney stone (NS) group comprised 39 LNR and 45 HNR individuals, while the kidney stone (KS) group consisted of 19 LNR and 50 HNR individuals. The distribution of oxalate in urine (p < 0.01) but not calcium (p = 0.741) was significantly varied among the four groups. Significant difference was found in the dietary patterns of people with KS and NS controls (X² = 5.744, p = 0.017). Forty-six discriminative bacteria were found among different dietary patterns groups in KS patients and NS controls. Not only gut bacteria such as Pseudomonas, Sphingomonas, Hydrogenoanaerobacterium, Faecalitalea, etc., but also metabolic pathways associated with inflammation, lipid, and mineral metabolism were found more abundant in KS patients with HNR dietary pattern. It is noteworthy that g__Prevotellaceae_UCG_001, g__hgcI_clade, and g__Bradyrhizobium were negatively related to water intake but instead had a positive correlation with salt and meat intake. Our study revealed that gut microbiota with significantly different abundance existed in the HNR dietary patterns compared to the LNR counterparts in both calcium oxalate KS and NS individuals. The dietary patterns may affect the prevention and management of calcium oxalate stones by regulating the homeostasis of gut microbiota.

Comparison of Metabolites and Gut Microbes between Patients with Parkinson’s Disease and Healthy Individuals—A Pilot Clinical Observational Study (STROBE Compliant)

Introduction: Even if levodopa, dopamine agonists, and others are used for patients with Parkinson’s disease, the effect is not sustained, and side effects such as motor fluctuation and dyskinesia are more likely to appear as the dose increases. Thus, new approaches for managing Parkinson’s disease are needed. This study aimed to compare the metabolites and gut microbes between patients with Parkinson’s disease and healthy individuals. Methods: This was an observational study with a case-control design. Metabolite and gut microbial analyses were performed using blood and stool samples collected from the subjects. Results: Among the metabolites, the acetate, citrate, methionine, and trimethylamine levels were significantly different between the two groups. In the gut microbes, abundance of Bacteroidetes, Prevotella, Phascolarctobacterium, Pseudoflavonifractor, Eisenbergiella, and Gemella were also significantly different between the two groups. Discussion: Metabolites are the products of gut microbes. Therefore, when the gut microbes change, the metabolites change accordingly. Metabolites and gut microbes that were significantly different between the two groups were mostly those involved in lipid and glucose metabolism. Our data may be helpful for the development of new drugs targeting metabolites and gut microbes through large-scale studies in the future.

Gut microbiome profiles in Thai healthy pregnant women and its association with types of foods

Background

Gut microbiome colonization during early life is significant for immunological and physiological development. Maternal microbiome is associated with proper development of infants. The aim of this study was to determine the gut microbiome profiles among Thai healthy pregnant women and its associated factors.

Methods

A multicenter, open trial prospective study was performed at three hospitals in Northern, Central, and Northeastern regions of Thailand. Thai healthy pregnant women attending antenatal clinics were recruited. Fecal samples of subjects at the third trimester of pregnancy were collected with sterilized techniques. The gut microbiome profiles and bacterial diversity were assessed using 16Ss RNA gene sequencing. Demographic data, dietary intake, and anthropometric data were recorded and analyzed.

Results

There were 86 healthy pregnant women. The dominant of gut microbiome profiles were Bacteroidetes and Firmicutes. Pregnant women in the Central region had significantly higher of Ruminococcaceae and Lachnospiraceae than those in other regions (p < 0.001). Pregnant women in the Northern region significantly consumed more glutinous rice than those in other regions (p < 0.001). Glutinous rice intake was positively correlated with Bacteroidetes (rho = 0.405, p = 0.01) and negatively correlated with Firmicutes (rho = − 0.440, p = 0.001). Alpha diversity was not correlated with pre-pregnancy body mass index (BMI) or gestational weight gain.

Conclusions

The gut microbiome profiles mainly found in Thai healthy pregnant women were Bacteroidetes and Firmicutes. The gut microbiome profiles in pregnant women found in this study possibly depended on dietary patterns. Glutinous rice with high amylopectin is probably related to abundance of Bacteroidetes.

Gut microbiota in patients with obesity and metabolic disorders - a systematic review

BACKGROUND

Previous observational studies have demonstrated inconsistent and inconclusive results of changes in the intestinal microbiota in patients with obesity and metabolic disorders. We performed a systematic review to explore evidence for this association across different geography and populations.

METHODS

We performed a systematic search of MEDLINE (OvidSP) and Embase (OvidSP) of articles published from Sept 1, 2010, to July 10, 2021, for case-control studies comparing intestinal microbiome of individuals with obesity and metabolic disorders with the microbiome of non-obese, metabolically healthy individuals (controls). The primary outcome was bacterial taxonomic changes in patients with obesity and metabolic disorders as compared to controls. Taxa were defined as "lean-associated" if they were depleted in patients with obesity and metabolic disorders or negatively associated with abnormal metabolic parameters. Taxa were defined as "obesity-associated" if they were enriched in patients with obesity and metabolic disorders or positively associated with abnormal metabolic parameters.

RESULTS

Among 2390 reports screened, we identified 110 full-text articles and 60 studies were included. Proteobacteria was the most consistently reported obesity-associated phylum. Thirteen, nine, and ten studies, respectively, reported Faecalibacterium, Akkermansia, and Alistipes as lean-associated genera. Prevotella and Ruminococcus were obesity-associated genera in studies from the West but lean-associated in the East. Roseburia and Bifidobacterium were lean-associated genera only in the East, whereas Lactobacillus was an obesity-associated genus in the West.

CONCLUSIONS

We identified specific bacteria associated with obesity and metabolic disorders in western and eastern populations. Mechanistic studies are required to determine whether these microbes are a cause or product of obesity and metabolic disorders.

New Insights Into Gut-Bacteria-Derived Indole and Its Derivatives in Intestinal and Liver Diseases

The interaction between host and microorganism widely affects the immune and metabolic status. Indole and its derivatives are metabolites produced by the metabolism of tryptophan catalyzed by intestinal microorganisms. By activating nuclear receptors, regulating intestinal hormones, and affecting the biological effects of bacteria as signaling molecules, indole and its derivatives maintain intestinal homeostasis and impact liver metabolism and the immune response, which shows good therapeutic prospects. We reviewed recent studies on indole and its derivatives, including related metabolism, the influence of diets and intestinal commensal bacteria, and the targets and mechanisms in pathological conditions, especially progress in therapeutic strategies. New research insights into indoles will facilitate a better understanding of their druggability and application in intestinal and liver diseases.

Gut microbiota in nonalcoholic fatty liver diseases with and without type-2 diabetes mellitus

BACKGROUND AND AIMS

The association between nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) is not very well described but gut microbiota composition is mentioned as a risk factor. The present study aimed to characterize the differences of dominant gut microbiota phyla among people with NAFLD as compared to T2DM and control groups.

PATIENTS AND METHODS

The major bacterial phylum of gut microbiota including Bacteroidetes, Firmicutes, Actinobacteria, Proteobacteria, and total bacteria of 15 NAFLD patients with T2DM, 15 NAFLD patients without T2DM, 15 patients with T2DM, and 20 healthy control subjects were assessed by a quantitative PCR (qPCR).

RESULTS

NAFLD patients with T2DM had significantly higher BMI, triglyceride level, and total cholesterol level were compared with controls (Pv < 0.05). Bacteroidetes and Firmicutes phyla were significantly low in NAFLD patients with T2DM (Firmicutes, 2.55 ± 2.25, Pv 0/0002 and Bacteroidetes, 1.55 ± 2.29, Pv 0/0007), while the content of Proteobacteria and Actinobacteria was high in NAFLD patients with T2DM group and there were no significant differences between phyla with NAFLD patients with T2DM group (Pv > 0.05). Furthermore, Firmicutes copy number was lower in the separate groups of NAFLD and T2DM as compared to the healthy controls (Pv < 0.05).

CONCLUSIONS

This study performed gut microbiota for the first time among NAFLD and TDM patients separately and together. This investigation indicated that NAFLD patients with T2DM have a different gut composition in comparison to NAFLD, T2DM alone, which could be associated with disease development.

Gut Microbiome-Mediated Alteration of Immunity, Inflammation, and Metabolism Involved in the Regulation of Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of end-stage liver disease, leading to a rapidly growing global public health burden. The term “gut microbiome (GM)” refers to the approximately 100 trillion microbial cells that inhabit the host’s gastrointestinal tract. There is increasing evidence that GM is involved in the pathogenesis of NAFLD and may be a potential target for intervention. To explore GM-based strategies for precise diagnosis and treatment of NAFLD, great efforts have been made to develop a comprehensive and in-depth understanding of the host–microbe interaction. This review evaluates this interaction critically, mainly considering the intricate regulation of the metabolism, immunity, and inflammatory status during the evolution of the disease pathogenesis, revealing roles for the GM in NAFLD by examining advances in potential mechanisms, diagnostics, and modulation strategies.

Synopsis: Considering the intricate metabolic and immune/inflammatory homeostasis regulation, we evaluate the latest understanding of the host–microbe interaction and reveal roles for the gastrointestinal microbiome in NAFLD. Strategies targeting the gastrointestinal microbiome for the diagnosis and treatment of NAFLD are proposed.

AST-120 Treatment Alters the Gut Microbiota Composition and Suppresses Hepatic Triglyceride Levels in Obese Mice

Background: The prevalence of nonalcoholic fatty liver disease (NAFLD) has been increasing worldwide. The existence of a relationship between the microbiota and the pathology of hepatic steatosis is also becoming increasingly clear. AST-120, an oral spherical carbon adsorbent, has been shown to be useful for delaying dialysis initiation and improving uremic symptoms in patients with chronic kidney disease. However, little is known about the effect of AST-120 on fatty liver.Methods: AST-120 (5% w/w) was administrated to 6-week-old male db/db mice for 8 weeks. The body weight, blood glucose and food consumption were examined. Hepatic triglyceride (TG) levels, lipid droplets and epididymal fat cell size were measured. The gut microbiota compositions were investigated in feces and cecum.Results: Significant decreases of the hepatic weight and hepatic TG levels were observed in the AST-120-treated db/db mice. Furthermore, AST-120 treatment was also associated with a decrease of Bacteroidetes, increase of Firmicutes, and a reduced ratio of Bacteroidetes to Firmicutes (B/F ratio) in the feces in the db/db mice. The B/F ratio in the feces was correlated with the liver weight and area of the liver occupied by lipid droplets in the db/db mice.Conclusions: These data suggest that AST-120 treatment alters the composition of the fecal microbiota and suppresses hepatic TG levels in the db/db mice.

Maturation of the Visceral (Gut-Adipose-Liver) Network in Response to the Weaning Reaction versus Adult Age and Impact of Maternal High-Fat Diet

Metabolic-associated fatty liver disease is a major cause of chronic pathologies, of which maternal obesity is a frequent risk factor. Gut wall and microbiota, visceral fat, and liver form a pre-systemic network for substrates and pro-inflammatory factors entering the body, undergoing accelerated maturation in early-life when the weaning reaction, i.e., a transitory inflammatory condition, affects lifelong health. We aimed to characterize organ metabolism in the above network, in relation to weaning reaction and maternal obesity. Weaning or 6-months-old offspring of high-fat-diet and normal-diet fed dams underwent in vivo imaging of pre-/post-systemic glucose uptake and tissue radiodensity in the liver, visceral fat, and intestine, a liver histology, and microbiota and metabolic pathway analyses. Weaning mice showed the dominance of gut Clostridia and Bacteroidia members, overexpressing pathways of tissue replication and inflammation; adulthood increased proneness to steatohepatitis, and Desulfovibrio and RF39 bacteria, and lipopolysaccharide, bile acid, glycosaminoglycan, and sphingolipid metabolic pathways. In vivo imaging could track organ maturation, liver inflammation, and protective responses. A maternal high-fat diet amplified the weaning reaction, elevating liver glucose uptake, triglyceride levels, and steatohepatitis susceptibility along the lifespan. The visceral network establishes a balance between metabolism and inflammation, with clear imaging biomarkers, and crucial modulation in the weaning time window.

Probiotics and Prebiotics as a Strategy for Non-Alcoholic Fatty Liver Disease, a Narrative Review

Non-alcoholic fatty liver disease (NAFLD) is a chronic non-communicable disease, with a prevalence of 25% worldwide. This pathology is a multifactorial illness, and is associated with different risks factors, including hypertension, hyperglycemia, dyslipidemia, and obesity. Beside these predisposing features, NAFLD has been related to changes in the microbiota, which favor the disease progression. In this context, the modulation of the gut microbiota has emerged as a new therapeutic target for the prophylaxis and treatment of NAFLD. This review describes the changes in the gut microbiota associated with NAFLD and the effect of probiotics, prebiotics, and synbiotics on the gut microbiota, liver damage, anthropometric parameters, blood lipids, inflammation markers and insulin resistance in these patients.

Contribution of gut microbiota to nonalcoholic fatty liver disease: Pathways of mechanisms

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is a common, multifactorial liver disease with rapidly increasing prevalence. During the past decade, several lines of evidence have suggested that gut microbiota dysbiosis represents a major factor contributing to NAFLD occurrence and its progression.

METHOD

We have performed a review of the published data on the relationship between gut microbiota and risk factors for NAFLD and the role that gut-liver axis plays in the pathogenesis of NAFLD.

RESULTS

Accumulated evidence has indicated that dysfunction of the gut-liver axis, including increased intestinal permeability, small intestinal bacterial overgrowth, microbiota-derived mediators, and intestinal dysbiosis contribute to the progression and development of NAFLD.

CONCLUSIONS

The findings of this review suggest that lifestyle modification and manipulation of gut microbiota can be considered as a therapeutic target for NAFLD management. However, important documents supporting the role of gut microbiota in NAFLD come from animal studies; therefore, information from studies on humans could lead to novel therapeutics for this highly common disorder.

Gut Microbiota and Non-Alcoholic Fatty Liver Disease Severity in Type 2 Diabetes Patients

Introduction: Non-alcoholic fatty liver disease (NAFLD) remains an important health issue worldwide. The increasing prevalence of NAFLD is linked to type 2 diabetes (T2D). The gut microbiota is associated with the development of NAFLD and T2D. However, the relationship between gut microbiota and NAFLD severity has remained unclear in T2D patients. The aim of this study was to evaluate the relationship of gut microbiota with the severity of NAFLD in T2D patients. Methods: This cross-sectional study used transient elastography (FibroScan) to evaluate the severity of hepatic steatosis. We utilized qPCR to measure the abundance of Bacteroidetes, Firmicutes, Faecalibacterium prausnitzii, Clostridium leptum group, Bacteroides, Bifidobacterium, Akkermansia muciniphila, and Escherichia coli. Results: Of 163 T2D patients, 83 with moderate to severe NAFLD had higher abundance of bacteria of the phylum Firmicutes with respect to 80 patients without NAFLD or with mild NAFLD. High abundance of the phylum Firmicutes increased the severity of NAFLD in T2D patients. A positive correlation between NAFLD severity and the phylum Firmicutes was found in T2D male patients with body mass index ≥24 kg/m² and glycated hemoglobin <7.5%. Conclusion: Enrichment of the fecal microbiota with the phylum Firmicutes is significantly and positively associated with NAFLD severity in T2D patients. The gut microbiota is a potential predictor of NAFLD severity in T2D patients.

Polychlorinated biphenyls altered gut microbiome in CAR and PXR knockout mice exhibiting toxicant-associated steatohepatitis

Polychlorinated biphenyls (PCBs) are persistent organic pollutants associated with non-alcoholic fatty liver disease (NAFLD). Previously, we demonstrated that the PCB mixture, Aroclor1260, exacerbated NAFLD, reflective of toxicant-associated steatohepatitis, in diet-induced obese mice, in part through pregnane-xenobiotic receptor (PXR) and constitutive androstane receptor (CAR) activation. Recent studies have also reported PCB-induced changes in the gut microbiome that consequently impact NAFLD. Therefore, the objective of this study is to examine PCB effects on the gut-liver axis and characterize the role of CAR and PXR in microbiome alterations. C57Bl/6 (wildtype, WT), CAR and PXR knockout mice were fed a high fat diet and exposed to Aroclor1260 (20 mg/kg, oral gavage, 12 weeks). Metagenomics analysis of cecal samples revealed that CAR and/or PXR ablation increased bacterial alpha diversity regardless of exposure status. CAR and PXR ablation also increased bacterial composition (beta diversity) versus WT; Aroclor1260 altered beta diversity only in WT and CAR knockouts. Distinct changes in bacterial abundance at different taxonomic levels were observed between WT and knockout groups; however Aroclor1260 had modest effects on bacterial abundance within each genotype. Notably, both knockout groups displayed increased Actinobacteria and Verrucomicrobia abundance. In spite of improved bacterial diversity, the knockout groups however failed to show protection from PCB-induced hepato- and intestinal- toxicity including decreased mRNA levels of ileal permeability markers (occludin, claudin3). In summary, CAR and PXR ablation significantly altered gut microbiome in diet-induced obesity while Aroclor1260 compromised intestinal integrity in knockout mice, implicating interactions between PCBs and CAR, PXR on the gut-liver axis.

Early intervention with probiotics and metformin alleviates liver injury in NAFLD rats via targeting gut microbiota dysbiosis and p-AKT/mTOR/LC-3II pathways

Non-alcoholic fatty liver disease (NAFLD) constitutes a major health problem worldwide and intimately links with obesity and diabetes. This study aimed to explore the therapeutic impact of early treatment with metformin (MTF) alone or in combination with Lactobacillus reuteri DSM 17938 (L. reuteri) + metronidazole (MTZ) in male Sprague Dawley rats with high-fat diet (HFD)-induced NAFLD. Hepatic steatosis was induced by feeding rats HFD for 6 weeks. MTF (150 mg/kg/day) or L. reuteri (2 × 10⁹ colony forming unit/day) were given orally for 4 weeks; meanwhile, MTZ (15 mg/kg/day, p.o.) was administered for 1 week. Administration of L. reuteri + MTZ in combination with MTF produced a superior effect concerning insulin resistance (IR), lipid profile, liver function, oxidative stress, inflammatory and autophagic markers than using each treatment alone. Besides, this combination resulted in disappearance of steatosis, inflammation and vacuolation within hepatic architecture. Moreover, it normalized short chain fatty acids (SCFAs) as well as Firmicutes and Bacteroidetes faecal contents. In conclusion, early treatment with L. reuteri + MTZ in combination with MTF could prevent NAFLD progression and liver injury through targeting gut dysbiosis, inflammation and autophagic pathways.

Sacran, a sulfated polysaccharide, suppresses the absorption of lipids and modulates the intestinal flora in non-alcoholic steatohepatitis model rats

AIMS

The objective of this study was to investigate the effects of administering sacran, a sulfated polysaccharide, on liver biology, gut microbiota, oxidative stress, and inflammation on stroke-prone spontaneously hypertensive (SHRSP5/Dmcr) rats that develop fibrotic steatohepatitis with histological similarities to that of non-alcoholic steatohepatitis (NASH).

MAIN METHODS

Four groups of 8-week-old SHRSP5/Dmcr rats were fed a high fat-cholesterol (HFC) diet for 4 and 8 weeks and administered either sacran (80 mg/kg/day) or a non-treatment, respectively. Liver function was evaluated by biochemical and histopathological analyses. Hepatic inflammatory markers were measured using mRNA expression. Fecal microbial profiles were determined via 16S rRNA sequencing. A triglyceride (TG) absorption test was administered to the 8-week-old Sprague-Dawley (SD) rats.

KEY FINDING

Sacran administration was observed to decrease the extent of oxidative stress and hepatic biochemical parameters in serum and hepatic injury with the levels of transforming growth factor-beta (TGF-β1) and tumor necrosis factor-alpha (TNF-α), being increased compared to those of the non-treatment group. At the genus level, sacran administration caused a significant decrease in the harmful Prevotella genus, and a significant increase in the useful Blautia genus was observed. Sacran administration also decreased the serum TG increase that was induced by administering corn oil to the SD rats.

SIGNIFICANCE

We conclude that sacran administration has the potential to reduce the absorption of lipids into blood and to improve several gut microbiotas, in the gastrointestinal tract, thereby inhibiting the subsequent development of oxidative stress and hepatic markers in the systematic circulation on NASH.

Impacts of Maternal Diet and Alcohol Consumption during Pregnancy on Maternal and Infant Gut Microbiota

(1) Background: Maternal diet and alcohol consumption can influence both maternal and infant's gut microbiota. These relationships are still not examined in the Chinese population. The purpose of this study was to explore the effect of alcohol consumption and maternal diet during pregnancy on maternal and infant's gut microbiota. (2) Methods: Twenty-nine mother-child dyads were enrolled in central China. Fecal samples of mothers during late pregnancy and of newborns within 48 h were collected. The V3-V4 regions of 16S rRNA sequences were analyzed. A self-administrated questionnaire about simple diet frequency in the past week was completed by mothers before childbirth. The demographic information was finished by mothers at 24 h after childbirth. (3) Results: Among these 29 mothers, 10 mothers reported alcohol consumption during pregnancy. The PCoA (β-diversity) showed significant difference in maternal gut microbiota between the alcohol consumption group vs. the non-alcohol consumption group (abund-Jaccard, r = 0.2, p = 0.006). The same phenomenon was observed in newborns (unweighted-UniFrac full tree, r = 0.174, p = 0.031). Maternal alcohol consumption frequency showed positive associations with maternal Phascolarctobacterium (p = 0.032) and Blautia (p = 0.019); maternal Faecalibacterium (p = 0.013) was negatively correlated with frequency of alcohol consumption. As for newborns, a positive relationship showed between Megamonas (p = 0.035) and newborns with maternal alcohol consumption. The diet was not associated with both maternal and infant's gut microbiota. (4) Conclusions: Maternal alcohol consumption during pregnancy influenced the gut microbiota on both mothers and the newborns. Future research is needed to explore these relationships in a lager birth cohort. Understanding the long-term effect of alcohol consumption on maternal and newborns' gut microbiota is needed.

Compositional alterations of gut microbiota in nonalcoholic fatty liver disease patients: a systematic review and Meta-analysis

Background

Although imbalanced intestinal flora contributes to the pathogenesis of nonalcoholic fatty liver disease (NAFLD), conflicting results have been obtained for patient-derived microbiome composition analyses. A meta-analysis was performed to summarize the characteristics of intestinal microbiota at the species level in NAFLD patients.

Methods

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement, a completed search (last update: December 30, 2020) of databases was performed to identify eligible case-control studies detecting gut microbiota in NAFLD patients. The meta-analysis results are presented as the standard mean difference (SMD) and 95% confidence interval (CI). Bias controls were evaluated with the Newcastle-Ottawa Scale (NOS), funnel plot analysis, and Egger’s and Begg’s tests.

Results

Fifteen studies (NOS score range: 6–8) that detected the gut microbiota in the stools of 1265 individuals (577 NAFLD patients and 688 controls) were included. It was found that Escherichia, Prevotella and Streptococcus (SMD = 1.55 [95% CI: 0.57, 2.54], 1.89 [95% CI: 0.02, 3.76] and 1.33 [95% CI: 0.62, 2.05], respectively) exhibited increased abundance while Coprococcus, Faecalibacterium and Ruminococcus (SMD = − 1.75 [95% CI: − 3.13, − 0.37], − 9.84 [95% CI: − 13.21, − 6.47] and − 1.84 [95% CI, − 2.41, − 1.27], respectively) exhibited decreased abundance in the NAFLD patients compared with healthy controls. No differences in the abundance of Bacteroides, Bifidobacterium, Blautia, Clostridium, Dorea, Lactobacillus, Parabacteroides or Roseburia were confirmed between the NAFLD patients and healthy controls.

Conclusions

This meta-analysis revealed that changes in the abundance of Escherichia, Prevotella, Streptococcus, Coprococcus, Faecalibacterium and Ruminococcus were the universal intestinal bacterial signature of NAFLD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-021-01440-w.

Characterization of Gut Microbiome in Liver Transplant Recipients With Nonalcoholic Steatohepatitis

Supplemental Digital Content is available in the text.

Nonalcoholic fatty liver disease (NAFLD) and its progressive form nonalcoholic steatohepatitis (NASH) are a growing problem globally and recur even after liver transplant (LT). We aim to characterize the gut dysbiosis in patients who developed recurrent NAFLD compared with patients without recurrence following LT.

Phenotyping non-alcoholic fatty liver disease by the gut microbiota: Ready for prime time?

BACKGROUND AND AIM

Several studies observed alterations in the gut microbiota in patients with non-alcoholic fatty liver disease (NAFLD). However, analyzed patient populations and methods strongly differ among these studies. The aim of this study was to prove the reproducibility of published results and to provide a detailed overview of all findings in our NAFLD cohort using next generation sequencing methods.

METHODS

The individual taxonomic microbiota composition of fecal samples from 90 NAFLD patients and 21 healthy controls was analyzed using 16S rRNA gene sequencing. Study participants were grouped according to their disease stage and compared regarding their gut microbiota composition. Studies were identified from PubMed listed publications, and the results were compared with the findings in our cohort.

RESULTS

Results from 13 identified studies were compared with our data. A decreased abundance of the Bacteroidetes and Ruminococcaceae as well as an increased abundance of Lactobacillaceae and Veillonellaceae and Dorea were the most frequently reported changes among NAFLD patients in 4/13, 5/13, 4/13, 2/13, and 3/13 studies, respectively. Even though these alterations in the gut microbiota composition were also observed in our patient cohort, the majority of published differences could not be reproduced, neither in our own nor in other NAFLD cohort studies.

CONCLUSION

Despite repeatedly reproduced abundance patterns of specific bacteria, the heterogeneous study results did not reveal a consistent disease specific gut microbiota signature. Further prospective studies with homogenous patient cohorts and standardized methods are necessary to phenotype NAFLD by the gut microbiota.

Cannabis Extracts Affected Metabolic Syndrome Parameters in Mice Fed High-Fat/Cholesterol Diet

Introduction: Nonalcoholic fatty liver disease (NAFLD) is associated with metabolic syndrome, which often includes obesity, diabetes, and dyslipidemia. Several studies in mice and humans have implicated the involvement of the gut microbiome in NAFLD. While cannabis may potentially be beneficial for treating metabolic disorders such as NAFLD, the effects of cannabis on liver diseases and gut microbiota profile are yet to be addressed. In this study, we evaluated the therapeutic effects of cannabis strains with different cannabinoid profiles on NAFLD progression. Materials and Methods: NAFLD was induced by feeding mice a high-fat/cholesterol diet (HFCD) for 6 weeks. During this period, cannabis extracts were administrated orally at a concentration of 5 mg/kg every 3 days. Profile of lipids, liver enzymes, glucose tolerance, and gene expression related to carbohydrate lipid metabolism and liver inflammation were analyzed. The effect of cannabis strains on microbiota composition in the gut was evaluated. Results: A cannabidiol (CBD)-rich extract produced an increase in inflammatory related gene expression and a less diverse microbiota profile, associated with increased fasting glucose levels in HFCD-fed mice. In contrast, mice receiving a tetrahydrocannabinol (THC)-rich extract exhibited moderate weight gain, improved glucose response curves, and a decrease in liver enzymes. Conclusions: The results of this study indicate that the administration of cannabis containing elevated levels of THC may help ameliorate symptoms of NAFLD, whereas administration of CBD-rich cannabis extracts may cause a proinflammatory effect in the liver, linked with an unfavorable change in the microbiota profile. Our preliminary data suggest that these effects are mediated by mechanisms other than increased expression of the endocannabinoid receptors cannabinoid receptor 1 (CB1) and CB2.

High oleic peanuts improve parameters leading to fatty liver development and change the microbiota in mice intestine

Background

Oleic-acid consumption can possibly prevent or delay metabolic diseases. In Israel, a Virginia-type peanut cultivar with a high content of oleic acid has been developed.

Objective

This study examined the effect of consuming high oleic peanuts (D7) on the development of fatty liver compared to the standard HN strain.

Design

The two peanut cultivars were added to normal diet (ND) and high-fat (HF) mouse diet. Male C57BL/6 mice were fed for 8 and 10 weeks on a 4% D7, 4% HN, or control diet. At the end of the experiments, blood and tissues were collected. Triglyceride, lipid levels, histology, and protein expression were examined. The diets’ effects on intestinal microbiota were also evaluated.

Results

Both D7 and HFD7 led to a reduction in plasma triglycerides. Lipids, triglycerides, and free fatty acids in the liver were low in diets containing D7. Additionally, CD36 expression decreased in the D7 group. Consumption of D7 led to higher Prevotella levels, and consumption of ND that contained HN or D7 led to a lower Firmicutes/Bacteroidetes ratio.

Conclusion

These findings suggest that consumption of peanuts high in oleic acid (D7) may have the potential to delay primary fatty liver symptoms.

Gut Microbiome in Psoriasis: An Updated Review

(1) Background: A growing body of evidence highlights that intestinal dysbiosis is associated with the development of psoriasis. The gut–skin axis is the novel concept of the interaction between skin diseases and microbiome through inflammatory mediators, metabolites and the intestinal barrier. The objective of this study was to synthesize current data on the gut microbial composition in psoriasis. (2) Methods: We conducted a systematic review of studies investigating intestinal microbiome in psoriasis, using the PRISMA checklist. We searched MEDLINE, EMBASE, and Web of Science databases for relevant published articles (2000–2020). (3) Results: All of the 10 retrieved studies reported alterations in the gut microbiome in patients with psoriasis. Eight studies assessed alpha- and beta-diversity. Four of them reported a lack of change in alpha-diversity, but all confirmed significant changes in beta-diversity. At the phylum-level, at least two or more studies reported a lower relative abundance of Bacteroidetes, and higher Firmicutes in psoriasis patients versus healthy controls. (4) Conclusions: There is a significant association between alterations in gut microbial composition and psoriasis; however, there is high heterogeneity between studies. More unified methodological standards in large-scale studies are needed to understand microbiota’s contribution to psoriasis pathogenesis and its modulation as a potential therapeutic strategy.

Antibiotic-Driven Gut Microbiome Disorder Alters the Effects of Sinomenine on Morphine-Dependent Zebrafish

Morphine is one of the most severely abused drugs in the world. Previous research on morphine addiction has focused on the central nervous system (CNS). Studies have shown that a two-way regulation of the brain and gut microbiota (GM), suggesting a link between GM and CNS disease. However, the functional mechanism underlying the relationship between intestinal flora and morphine dependence is unclear. In this study, the effect of sinomenine on morphine addiction was evaluated based on the microbiota-gut-brain axis (MGBA). The results show that the GM plays an important role in morphine dependence. Morphine treatment induced zebrafish conditional position preference (CPP), and significantly changed zebrafish GM characteristics and the expression of MGBA-related genes in the zebrafish brain and intestine. Importantly, sinomenine, an alkaloid with a similar structure to morphine, can reverse these morphine-induced changes. Subsequently, morphine-dependent CPP training was performed after antibiotic administration. After antibiotic treatment, zebrafish CPP behavior, the composition and proportions of the zebrafish GM, and the expression of MGBA-related genes in zebrafish were changed. More interestingly, sinomenine was no longer effective in treating morphine dependence, indicating that antibiotic-driven intestinal flora imbalance alters the efficacy of sinomenine on morphine-dependent zebrafish. This study confirms that the MGBA is bidirectionally regulated, highlighting the key role of the GM in the formation and treatment of morphine dependence, and may provide new treatment strategies for using traditional Chinese medicine to treat drug addiction.

The Molecular and Mechanistic Insights Based on Gut-Liver Axis: Nutritional Target for Non-Alcoholic Fatty Liver Disease (NAFLD) Improvement

Non-alcoholic fatty liver disease (NAFLD) is recognized as the most frequent classification of liver disease around the globe. Along with the sequencing technologies, gut microbiota has been regarded as a vital factor for the maintenance of human and animal health and the mediation of multiple diseases. The modulation of gut microbiota as a mechanism affecting the pathogenesis of NAFLD is becoming a growing area of concern. Recent advances in the communication between gut and hepatic tissue pave novel ways to better explain the molecular mechanisms regarding the pathological physiology of NAFLD. In this review, we recapitulate the current knowledge of the mechanisms correlated with the development and progression of NAFLD regulated by the gut microbiome and gut-liver axis, which may provide crucial therapeutic strategies for NAFLD. These mechanisms predominantly involve: (1) the alteration in gut microbiome profile; (2) the effects of components and metabolites from gut bacteria (e.g., lipopolysaccharides (LPS), trimethylamine-N-oxide (TMAO), and N,N,N-trimethyl-5-aminovaleric acid (TMAVA)); and (3) the impairment of intestinal barrier function and bile acid homeostasis. In particular, the prevention and therapy of NAFLD assisted by nutritional strategies are highlighted, including probiotics, functional oligosaccharides, dietary fibers, ω-3 polyunsaturated fatty acids, functional amino acids (L-tryptophan and L-glutamine), carotenoids, and polyphenols, based on the targets excavated from the gut-liver axis.

Non-alcoholic fatty liver diseases: from role of gut microbiota to microbial-based therapies

Non-alcoholic fatty liver disease (NAFLD) is the well-known disease of the liver in adults and children throughout the world. The main manifestations related to NAFLD are an unusual storage of lipid in hepatocytes (hepatic steatosis) and progression of inflammation for non-alcoholic steatohepatitis (NASH). NAFLD is described as a multifactorial complication due to the genetic predisposition, metabolic functions, inflammatory, gut microbiota (GM), and environmental factors. The GM dysregulation among these factors is correlated to NAFLD development. In recent decades, advanced microbial profiling methods are continuing to shed light on the nature of the changes in the GM caused by NASH and NAFLD. In the current review, we aim to perform a literature review in different library databases and electronic searches (Science Direct, PubMed, and Google Scholar) which were randomly obtained. This will be done in order to provide an overview of the relation between GM and NAFLD, and the role of prebiotics, probiotics, and fecal microbiota transplantation (FMT), as potential therapeutic challenges for NAFLD.

Role of Gut Dysbiosis in Liver Diseases: What Have We Learned So Far?

Accumulating evidence supports that gut dysbiosis may relate to various liver diseases. Alcoholics with high intestinal permeability had a decrease in the abundance of Ruminnococcus. Intestinal dysmotility, increased gastric pH, and altered immune responses in addition to environmental and genetic factors are likely to cause alcohol-associated gut microbial changes. Alcohol-induced dysbiosis may be associated with gut barrier dysfunction, as microbiota and their products modulate barrier function by affecting epithelial pro-inflammatory responses and mucosal repair functions. High levels of plasma endotoxin are detected in alcoholics, in moderate fatty liver to advanced cirrhosis. Decreased abundance of Faecalibacterium prausnitzii, an anti-inflammatory commensal, stimulating IL-10 secretion and inhibiting IL-12 and interferon-γ expression. Proteobacteria, Enterobacteriaceae, and Escherichia were reported to be increased in NAFLD (nonalcoholic fatty liver disease) patients. Increased abundance of fecal Escherichia to elevated blood alcohol levels in these patients and gut microbiota enriched in alcohol-producing bacteria produce more alcohol (alcohol hypothesis). Some undetermined pathological sequences related to gut dysbiosis may facilitate energy-producing and proinflammatory conditions for the progression of NAFLD. A shortage of autochthonous non-pathogenic bacteria and an overgrowth of potentially pathogenic bacteria are common findings in cirrhotic patients. The ratio of the amounts of beneficial autochthonous taxa (Lachnospiraceae + Ruminococaceae + Veillonellaceae + Clostridiales Incertae Sedis XIV) to those of potentially pathogenic taxa (Enterobacteriaceae + Bacteroidaceae) was low in those with early death and organ failure. Cirrhotic patients with decreased microbial diversity before liver transplantation were more likely to develop post-transplant infections and cognitive impairment related to residual dysbiosis. Patients with PSC had marked reduction of bacterial diversity. Enterococcus and Lactobacillus were increased in PSC patients (without liver cirrhosis.) Treatment-naive PBC patients were associated with altered composition and function of gut microbiota, as well as a lower level of diversity. As serum anti-gp210 antibody has been considered as an index of disease progression, relatively lower species richness and lower abundance of Faecalibacterium spp. in gp210-positive patients are interesting. The dysbiosis-induced altered bacterial metabolites such as a hepatocarcinogenesis promotor DCA, together with a leaky gut and bacterial translocation. Gut protective Akkermansia and butyrate-producing genera were decreased, while genera producing-lipopolysaccharide were increased in early hepatocellular carcinoma (HCC) patients.

The Role of Probiotics in Nonalcoholic Fatty Liver Disease: A New Insight into Therapeutic Strategies

Nonalcoholic fatty liver disease (NAFLD) encompasses a broad spectrum of pathological hepatic conditions ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), which may predispose to liver cirrhosis and hepatocellular carcinoma (HCC). Due to the epidemic obesity, NAFLD is representing a global health issue and the leading cause of liver damage worldwide. The pathogenesis of NAFLD is closely related to insulin resistance (IR), adiposity and physical inactivity as well as genetic and epigenetic factors corroborate to the development and progression of hepatic steatosis and liver injury. Emerging evidence has outlined the implication of gut microbiota and gut-derived endotoxins as actively contributors to NAFLD pathophysiology probably due to the tight anatomo-functional crosstalk between the gut and the liver. Obesity, nutrition and environmental factors might alter intestinal permeability producing a favorable micro-environment for bacterial overgrowth, mucosal inflammation and translocation of both invasive pathogens and harmful byproducts, which, in turn, influence hepatic fat composition and exacerbated pro-inflammatory and fibrotic processes. To date, no therapeutic interventions are available for NAFLD prevention and management, except for modifications in lifestyle, diet and physical exercise even though they show discouraging results due to the poor compliance of patients. The premise of this review is to discuss the role of gut–liver axis in NAFLD and emphasize the beneficial effects of probiotics on gut microbiota composition as a novel attractive therapeutic strategy to introduce in clinical practice.