Microbiota diversity in nonalcoholic fatty liver disease and in drug-induced liver injury

Evidence from mendelian randomization identifies several causal relationships between primary membranous nephropathy and gut microbiota

BACKGROUND

Research has showcased a correlation between disruptions in gut microbiota and primary membranous nephropathy (pMN), giving rise to the concept of the 'gut-kidney axis'. However, the precise relationship between gut microbiota and pMN remains elusive. Hence, this study endeavors to investigate whether a causal relationship exists between gut microbiota and pMN utilizing Mendelian randomization (MR) analysis.

METHODS

The primary method employed for MR analysis is the inverse variance weighting method, supplemented by MR-Egger and the weighted median method, to infer causality. This approach was validated within the pMN cohort across two distinct populations.

RESULTS

At the species level, the abundance of Bifidobacterium bifidum and Alistipes indistinctus was negatively correlated with the risk of pMN. Conversely, pMN was positively associated with Bacilli abundance at the class level, Lachnospiraceae abundance at the family level, and Dialister abundance at the genus level. Specifically, at the species level, pMN was positively correlated with the abundance of Ruminococcus lactaris, Dialister invisus, and Coprococcus_sp_ART55_1.

CONCLUSION

These findings lay the groundwork for future research exploring the interplay between pMN and the gut microbiota, with substantial implications for the prevention and treatment of pMN and its associated complications.

Jingangteng capsules ameliorate liver lipid disorders in diabetic rats by regulating microflora imbalances, metabolic disorders, and farnesoid X receptor

BACKGROUND

The plant Smilax china L., also known as Jingangteng, is suspected of regulating glucose and lipid metabolism. Jingangteng capsules (JGTCs) are commonly used to treat gynecological inflammation in clinical practice. However, it is not clear whether JGTCs can regulate glucose and lipid metabolism, and the mechanism is unclear.

PURPOSE

To investigate the impact and mechanism of action of JGTCs on diabetes and liver lipid disorders in rats.

METHODS

The chemical constituents of JGTCs were examined using ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry. A high-fat diet and streptozotocin-induced diabetes model was used to evaluate anti-diabetic effects by assessing blood glucose and lipid levels and liver function. The mechanism was explored using fecal 16S rRNA gene sequencing and metabolomics profiling, reverse transcription-quantiative polymerase chain reaction (RT-qPCR), and Western blot analysis.

RESULTS

Thirty-three components were identified in JGTCs. The serological and histomorphological assays revealed that JGTC treatment reduced levels of blood glucose and lipids, aspartate aminotransferase, alanine aminotransferase, and lipid accumulation in the liver of diabetic rats. According to 16S rDNA sequencing, JGTCs improved species richness and diversity in diabetic rats' intestinal flora and restored 22 dysregulated bacteria to control levels. Fecal metabolomics analysis showed that the altered fecal metabolites were rich in metabolites, such as histidine, taurine, low taurine, tryptophan, glycerophospholipid, and arginine. Serum metabolomics analysis indicated that serum metabolites were enriched in the metabolism of glycerophospholipids, fructose and mannose, galactose, linoleic acid, sphingolipids, histidine, valine, leucine and isoleucine biosynthesis, and tryptophan metabolism. Heatmaps revealed a strong correlation between metabolic parameters and gut microbial phylotypes. Molecular biology assays showed that JGTC treatment reversed the decreased expression of farnesoid X receptor (FXR) in the liver of diabetic rats and inhibited the expression of lipogenic genes (Srebp1c and FAS) as well as inflammation-related genes (interleukin (IL)-β, tumor necrosis factor (TNF)-α, and IL-6). Liver metabolomics analysis indicated that JGTC could significantly regulate a significant number of bile acid metabolites associated with FXR, such as glyco-beta-muricholic acid, glycocholic acid, tauro-beta-muricholic acid, and tauro-gamma-muricholic acid.

CONCLUSIONS

This was the first study to investigate the mechanisms of JGTCs' effects on liver lipid disorders in diabetic rats. JGTCs inhibited liver lipid accumulation and inflammatory responses in diabetic rats by affecting intestinal flora and metabolic disorders and regulating FXR-fat synthesis-related pathways to alleviate diabetic lipid disorders.

Role of Gut Microecology in the Pathogenesis of Drug-Induced Liver Injury and Emerging Therapeutic Strategies

Drug-induced liver injury (DILI) is a common clinical pharmacogenic disease. In the United States and Europe, DILI is the most common cause of acute liver failure. Drugs can cause hepatic damage either directly through inherent hepatotoxic properties or indirectly by inducing oxidative stress, immune responses, and inflammatory processes. These pathways can culminate in hepatocyte necrosis. The role of the gut microecology in human health and diseases is well recognized. Recent studies have revealed that the imbalance in the gut microecology is closely related to the occurrence and development of DILI. The gut microecology plays an important role in liver injury caused by different drugs. Recent research has revealed significant changes in the composition, relative abundance, and distribution of gut microbiota in both patients and animal models with DILI. Imbalance in the gut microecology causes intestinal barrier destruction and microorganism translocation; the alteration in microbial metabolites may initiate or aggravate DILI, and regulation and control of intestinal microbiota can effectively mitigate drug-induced liver injury. In this paper, we provide an overview on the present knowledge of the mechanisms by which DILI occurs, the common drugs that cause DILI, the gut microbiota and gut barrier composition, and the effects of the gut microbiota and gut barrier on DILI, emphasizing the contribution of the gut microecology to DILI.

Drug-Induced Liver Injury Due to Doxycycline: A Case Report and Review of Literature

Antibiotics are among the most common causes of drug-induced liver injury worldwide. Amoxicillin/clavulanic acid and nitrofurantoin are the most common culprits while tetracyclines are a rare cause of liver injury. Among tetracyclines, minocycline has been reported more frequently than doxycycline, which is an extremely rare cause of drug-induced liver injury. We present a healthy 28-year-old male patient from rural United States who was taking doxycycline for Lyme disease. After five days of therapy, he developed nausea, vomiting, fatigue, and significant transaminitis consistent with a hepatocellular pattern of liver injury. After a thorough workup which ruled out other causes such as infection, autoimmune diseases, liver malignancy, and vascular, structural, and metabolic disorders, his liver injury was attributed to doxycycline. We reached the diagnosis also by demonstrating a consistent temporal association between doxycycline intake and liver injury and the patient recovered completely with the cessation of doxycycline. Recognition of doxycycline as a cause of drug-induced liver injury should be considered in patients utilizing this antibiotic. Doxycycline, unlike minocycline, has a short latency period. Early recognition and discontinuation of doxycycline in our patient resulted in the complete resolution of symptoms and transaminitis preventing further morbidity and mortality.

Gestational supplementation of Bifidobacterium, Lactobacillus, and Streptococcus thermophilus attenuates hepatic steatosis in offspring mice through promoting fatty acid β-oxidation

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 β-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 β-oxidation.

Phlorizin Limits Bovine Viral Diarrhea Virus Infection in Mice via Regulating Gut Microbiota Composition

Phlorizin (PHZ) is one of the main pharmacologically active ingredients in Lithocarpus polystachyus. We have previously shown that PHZ inhibits the replication of bovine viral diarrhea virus (BVDV), but the exact antiviral mechanism, especially in vivo, is still unknown. Here, we further confirm that PHZ has good protective effects in BVDV-infected mice. We analyzed BVDV-induced CD3+, CD4+, and CD8+ T cells among peripheral blood lymphocytes and found that PHZ significantly restored their percentage. Metagenomic analyses revealed that PHZ markedly improved the richness and diversity of intestinal microbiota and increased the abundance of potentially health-related microbes (families Lachnosipiraceae, Ruminococcaceae, and Oscillospiraceae). Specifically, the relative abundance of short chain fatty acid (SCFA)-producing bacteria, including Lachnospiraceae_UCG-006, unclassified_f_Ruminococcaceae, Oscillibacter, Intestinimonas, Blautia, and Lachnoclostridium increased significantly after PHZ treatment. Interestingly, BVDV-infected mice that received fecal microbiota from PHZ-treated mice (PHZ-FMT) had a significantly lower viral load in the duodenum and jejunum than untreated mice. Pathological lesions of duodenum and jejunum were also greatly reduced in the PHZ-FMT group, confirming a significant antiviral effect. These findings show that gut microbiota play an important role in PHZ's antiviral activity and suggest that their targeted intervention might be a promising endogenous strategy to prevent and control BVDV.

Nonalcoholic Fatty Liver Disease: Changes in Gut Microbiota and Blood Lipids

Background and Aims

The global prevalence of nonalcoholic fatty liver disease (NAFLD) is 25%. This study aimed to explore differences in the gut microbial community and blood lipids between normal livers and those affected by NAFLD using 16S ribosomal deoxyribonucleic acid sequencing.

Methods

Gut microbiome profiles of 40 NAFLD and 20 non-NAFLD controls were analyzed. Information about four blood lipids and 13 other clinical features was collected. Patients were divided into three groups by ultrasound and FibroScan, those with a normal liver, mild FL (FL1), and moderate-to-severe FL (FL2). FL1 and FL2 patients were divided into two groups, those with either hyperlipidemia or non-hyperlipidemia based on their blood lipids. Potential keystone species within the groups were identified using univariate analysis and a specificity-occupancy plot. Significant difference in biochemical parameters ion NAFLD patients and healthy individuals were identified by detrended correspondence analysis and canonical correspondence analysis.

Results

Decreased gut bacterial diversity was found in patients with NAFLD. Firmicutes/Bacteroidetes decreased as NAFLD progressed. Faecalibacterium and Ruminococcus 2 were the most representative fatty-related bacteria. Glutamate pyruvic transaminase, aspartate aminotransferase, and white blood cell count were selected as the most significant biochemical indexes. Calculation of areas under the curve identified two microbiomes combined with the three biochemical indexes that identified normal liver and FL2 very well but performed poorly in diagnosing FL1.

Conclusions

Faecalibacterium and Ruminococcus 2, combined with glutamate pyruvic transaminase, aspartate aminotransferase, and white blood cell count distinguished NAFLD. We speculate that regulating the health of gut microbiota may release NAFLD, in addition to providing new targets for clinicians to treat NAFLD.

Alteration of Gut Microbiota Composition in the Progression of Liver Damage in Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a complex disorder whose prevalence is rapidly growing in South America. The disturbances in the microbiota-gut-liver axis impact the liver damaging processes toward fibrosis. Gut microbiota status is shaped by dietary and lifestyle factors, depending on geographic location. We aimed to identify microbial signatures in a group of Chilean MASLD patients. Forty subjects were recruited, including healthy controls (HCs), overweight/obese subjects (Ow/Ob), patients with MASLD without fibrosis (MASLD/F-), and MASLD with fibrosis (MASLD/F+). Both MASLD and fibrosis were detected through elastography and/or biopsy, and fecal microbiota were analyzed through deep sequencing. Despite no differences in α- and β-diversity among all groups, a higher abundance of Bilophila and a lower presence of Defluviitaleaceae, Lachnospiraceae ND3007, and Coprobacter was found in MASLD/F- and MASLD/F+, compared to HC. Ruminococcaceae UCG-013 and Sellimonas were more abundant in MASLD/F+ than in Ow/Ob; both significantly differed between MASLD/F- and MASLD/F+, compared to HC. Significant positive correlations were observed between liver stiffness and Bifidobacterium, Prevotella, Sarcina, and Acidaminococcus abundance. Our results show that MASLD is associated with changes in bacterial taxa that are known to be involved in bile acid metabolism and SCFA production, with some of them being more specifically linked to fibrosis.

Cannabidiol Inhibits Epithelial Ovarian Cancer: Role of Gut Microbiome

Epithelial ovarian cancer is among the deadliest gynecological tumors worldwide. Clinical treatment usually consists of surgery and adjuvant chemo- and radiotherapies. Due to the high rate of recurrence and rapid development of drug resistance, the current focus of research is on finding effective natural products with minimal toxic side effects for treating epithelial ovarian tumors. Cannabidiol is among the most abundant cannabinoids and has a non-psychoactive effect compared to tetrahydrocannabinol, which is a key advantage for clinical application. Studies have shown that cannabidiol has antiproliferative, pro-apoptotic, cytotoxic, antiangiogenic, anti-inflammatory, and immunomodulatory properties. However, its therapeutic value for epithelial ovarian tumors remains unclear. This study aims to investigate the effects of cannabidiol on epithelial ovarian tumors and to elucidate the underlying mechanisms. The results showed that cannabidiol has a significant inhibitory effect on epithelial ovarian tumors. In vivo experiments demonstrated that cannabidiol could inhibit tumor growth by modulating the intestinal microbiome and increasing the abundance of beneficial bacteria. Western blot assays showed that cannabidiol bound to EGFR/AKT/MMPs proteins and suppressed EGFR/AKT/MMPs expression in a dose-dependent manner. Network pharmacology and molecular docking results suggested that cannabidiol could affect the EGFR/AKT/MMPs signaling pathway.

Bacteroides fragilis aggravates high-fat diet-induced non-alcoholic fatty liver disease by regulating lipid metabolism and remodeling gut microbiota

Gut microbiota dysbiosis is a prominent determinant that significantly contributes to the disruption of lipid metabolism. Consequently, it is essential to the occurrence and development of non-alcoholic fatty liver disease (NAFLD). Nevertheless, the connection between diet and symbiotic gut microbiota in the progression of NAFLD remains uncertain. The purpose of this study was to explore the role of supplementing commensal Bacteroides fragilis (B. fragilis) on lipid metabolism, gut microbiota, and metabolites in high-fat diet (HFD)-fed mice, elucidating the impact of gut microbiota and metabolites on the development of NAFLD. Our study revealed that supplementation with B. fragilis exacerbated both weight gain and obesity in mice. B. fragilis exacerbated blood glucose levels and liver dysfunction in mice. Furthermore, an increase in liver lipid accumulation and the upregulation of genes correlated with lipid metabolism were observed in mice. Under an HFD, supplementation of commensal B. fragilis resulted in alterations in the gut microbiota, notably a significant increase in Desulfovibrionaceae, which led to elevated endotoxin levels and thereby influenced the progression of NAFLD. It was interesting that the simultaneous examination of gut microbiota metabolites revealed a more pronounced impact of diet on short-chain fatty acids. This study represented the pioneering investigation into the impact of B. fragilis on NAFLD. Our findings demonstrated that B. fragilis induced dysregulation in the intestinal microbiota, leading to elevated levels of lipopolysaccharide and dysfunction in glucose and lipid metabolism, thereby exacerbating NAFLD.IMPORTANCESome intestinal symbiotic microbes are involved in the occurrence of the metabolic disorders. Our study investigated the impact of supplementing commensal Bacteroides fragilis on host metabolism in high-fat diet-fed mice. Research results indicated that adding a specific bacterial strain to the complex intestinal microecology can worsen metabolic conditions. This effect mainly affects the structural diversity of intestinal microorganisms, the increase in harmful bacteria in the gut, and the elevation of endotoxin levels, blood glucose, and lipid metabolism, thereby impacting the progression of non-alcoholic fatty liver disease (NAFLD). Understanding the principles that govern the establishment of microbial communities comprising multiple species is crucial for preventing or repairing dysfunctions in these communities, thereby enhancing host health and facilitating disease treatment. This study demonstrated that gut microbiota dysbiosis could contribute to metabolic dysfunction and provides new insights into how to promote gut microbiota in the prevention and therapy of NAFLD.

Gut microbes combined with metabolomics reveal the protective effects of Qijia Rougan decoction against CCl4-induced hepatic fibrosis

Background: The occurrence and development of Hepatic fibrosis (HF) are closely related to the gut microbial composition and alterations in host metabolism. Qijia Rougan decoction (QJ) is a traditional Chinese medicine compound utilized clinically for the treatment of HF with remarkable clinical efficacy. However, its effect on the gut microbiota and metabolite alterations is unknown. Therefore, our objective was to examine the impact of QJ on the gut microbiota and metabolism in Carbon tetrachloride (CCl4)-induced HF. Methods: 40% CCl4 was used to induce HF, followed by QJ administration for 6 weeks. Serum biochemical analyses, histopathology, immunohistochemistry, RT-PCR, 16S rRNA gene sequencing, and non-targeted metabolomics techniques were employed in this study to investigate the interventional effects of QJ on a CCl4-induced HF model in rats. Results: This study demonstrated that QJ could effectively ameliorate CCl4-induced hepatic inflammation and fibrosis. Moreover, QJ upregulated the expression of intestinal tight junction proteins (TJPs) and notably altered the abundance of some gut microbes, for example, 10 genera closely associated with HF-related indicators and TJPs. In addition, metabolomics found 37 key metabolites responded to QJ treatment and strongly associated with HF-related indices and TJPs. Furthermore, a tight relation between 10 genera and 37 metabolites was found post correlation analysis. Among them, Turicibacter, Faecalibaculum, Prevotellaceae UCG 001, and unclassified Peptococcaceae may serve as the core gut microbes of QJ that inhibit HF. Conclusion: These results suggest that QJ ameliorates hepatic inflammation and fibrosis, which may be achieved by improving intestinal tight junctions and modulating gut microbiota composition as well as modulating host metabolism.

Symbiotic combination of Akkermansia muciniphila and inosine alleviates alcohol-induced liver injury by modulating gut dysbiosis and immune responses

Background

Alcoholic liver disease (ALD) is exacerbated by disruptions in intestinal microecology and immune imbalances within the gut-liver axis. The present study assesses the therapeutic potential of combining Akkermansia muciniphila (A. muciniphila) with inosine in alleviating alcohol-induced liver injury.

Methods

Male C57BL/6 mice, subjected to a Lieber-DeCarli diet with 5% alcohol for 4 weeks, served as the alcoholic liver injury model. Various analyzes, including quantitative reverse transcription polymerase chain reaction (qRT-PCR), ELISA, immunochemistry, 16S rRNA gene sequencing, and flow cytometry, were employed to evaluate liver injury parameters, intestinal barrier function, microbiota composition, and immune responses.

Results

Compared to the model group, the A. muciniphila and inosine groups exhibited significantly decreased alanine aminotransferase, aspartate aminotransferase, and lipopolysaccharide (LPS) levels, reduced hepatic fat deposition and neutrophil infiltration, alleviated oxidative stress and inflammation, and increased expression of intestinal tight junction proteins (Claudin-1, Occludin, and ZO-1). These effects were further pronounced in the A. muciniphila and inosine combination group compared to individual treatments. While alcohol feeding induced intestinal dysbiosis and gut barrier disruption, the combined treatment reduced the abundance of harmful bacteria (Oscillibacter, Escherichia/Shigella, and Alistipes) induced by alcohol consumption, promoting the growth of butyrate-producing bacteria (Akkermansia, Lactobacillus, and Clostridium IV). Flow cytometry revealed that alcohol consumption reduced T regulatory (Treg) populations while increasing those of T-helper (Th) 1 and Th17, which were restored by A. muciniphila combined with inosine treatment. Moreover, A. muciniphila and inosine combination increased the expression levels of intestinal CD39, CD73, and adenosine A2A receptor (A2AR) along with enhanced proportions of CD4+CD39+Treg and CD4+CD73+Treg cells in the liver and spleen. The A2AR antagonist KW6002, blocked the beneficial effects of the A. muciniphila and inosine combination on liver injury in ALD mice.

Conclusion

This study reveals that the combination of A. muciniphila and inosine holds promise for ameliorating ALD by enhancing the gut ecosystem, improving intestinal barrier function, upregulating A2AR, CD73, and CD39 expression, modulating Treg cells functionality, and regulating the imbalance of Treg/Th17/Th1 cells, and these beneficial effects are partly A2AR-dependent.

Gut microbiome features and metabolites in non-alcoholic fatty liver disease among community-dwelling middle-aged and older adults

BACKGROUND

The specific microbiota and associated metabolites linked to non-alcoholic fatty liver disease (NAFLD) are still controversial. Thus, we aimed to understand how the core gut microbiota and metabolites impact NAFLD.

METHODS

The data for the discovery cohort were collected from the Guangzhou Nutrition and Health Study (GNHS) follow-up conducted between 2014 and 2018. We collected 272 metadata points from 1546 individuals. The metadata were input into four interpretable machine learning models to identify important gut microbiota associated with NAFLD. These models were subsequently applied to two validation cohorts [the internal validation cohort (n = 377), and the prospective validation cohort (n = 749)] to assess generalizability. We constructed an individual microbiome risk score (MRS) based on the identified gut microbiota and conducted animal faecal microbiome transplantation experiment using faecal samples from individuals with different levels of MRS to determine the relationship between MRS and NAFLD. Additionally, we conducted targeted metabolomic sequencing of faecal samples to analyse potential metabolites.

RESULTS

Among the four machine learning models used, the lightGBM algorithm achieved the best performance. A total of 12 taxa-related features of the microbiota were selected by the lightGBM algorithm and further used to calculate the MRS. Increased MRS was positively associated with the presence of NAFLD, with odds ratio (OR) of 1.86 (1.72, 2.02) per 1-unit increase in MRS. An elevated abundance of the faecal microbiota (f__veillonellaceae) was associated with increased NAFLD risk, whereas f__rikenellaceae, f__barnesiellaceae, and s__adolescentis were associated with a decreased presence of NAFLD. Higher levels of specific gut microbiota-derived metabolites of bile acids (taurocholic acid) might be positively associated with both a higher MRS and NAFLD risk. FMT in mice further confirmed a causal association between a higher MRS and the development of NAFLD.

CONCLUSIONS

We confirmed that an alteration in the composition of the core gut microbiota might be biologically relevant to NAFLD development. Our work demonstrated the role of the microbiota in the development of NAFLD.

Polysaccharide from Panax japonicus C.A. Mey prevents non-alcoholic fatty liver disease development based on regulating liver metabolism and gut microbiota in mice

In this study, a new polysaccharide (PSPJ) with specific molecular weight and monosaccharide compositions was isolated and purified from the water extract of Panacis Japonici Rhizoma (PJR). 16S rRNA analysis and untargeted metabolomic analysis were used to assess PSPJ's efficacy in averting non-alcoholic fatty liver disease (NAFLD). This study indicated that PSPJ significantly reduced liver fat accumulation, the increase in blood lipids and ALT caused by HFD, indicating that PSPJ can prevent NAFLD. We demonstrated through cell experiments that PSPJ does not directly affect liver cells. The gut microbiota disorder and alterations in short-chain fatty acids (SCFAs) induced by the high-fat diet (HFD) were ameliorated by PSPJ, as evidenced by the analysis of 16S rRNA. In particular, supplementing PSPJ reduced the abundance of Turicibacter, Dubosiella, and Staphylococcus, and increased the abundance of Bacteroides, Blautia, and Lactobacillus. Untargeted metabolomic analysis shows that PSPJ improves liver metabolic disorders by regulating arachidonic acid metabolism, carbohydrate digestion and absorption, fatty acid biosynthesis, fatty acid metabolism and retinol metabolism. The findings of our investigation indicate that PSPJ has the potential to modulate liver metabolism through alterations in the composition of intestinal bacteria, hence preventing NAFLD.

Chronic exposure to parabens promotes non-alcoholic fatty liver disease in association with the changes of the gut microbiota and lipid metabolism

Non-alcoholic fatty liver disease (NAFLD) has become a serious public health issue due to changing dietary patterns and composition. However, the relationship between NAFLD occurrence and food additives, such as preservatives, remains unknown. This study aimed to evaluate the toxicity of parabens, namely methylparaben (MeP) and ethylparaben (EtP), in relation to NAFLD occurrence in mice under different dietary conditions. Exposure to MeP and EtP exacerbated high-fat diet (HFD)-induced obesity, glucose intolerance, higher serum lipid concentrations, and fat accumulation by upregulating genes involved in lipid metabolism. Untargeted metabolomics revealed that arachidonic acid (AA) metabolism was the top enriched pathway upon MeP and EtP exposure in the presence of HFD. 11,12-Epoxyeicosatrienoic acid (11,12-EET) was the most abundant AA metabolite and was significantly reduced upon exposure to MeP or EtP. Moreover, an integrative analysis of differential fecal taxa at the genus level and serum AA metabolites revealed significant associations. In addition, MeP and EtP enhanced lipid accumulation in AML12 cells and HepG2 cells cultured with oleic acid. 11,12-EET supplementation could significantly alleviate lipid accumulation by suppressing the expression of lipid metabolism-related genes and proteins. The present study suggests that chronic exposure to MeP and EtP promoted NAFLD via gut microbiota-dependent AA metabolism. These results highlight the need for reducing oral exposure to synthetic preservatives to improve metabolic disturbance under HFD conditions.

Gut-Liver Axis as a Therapeutic Target for Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is a liver disease that remains difficult to predict and diagnose, and the underlying mechanisms are yet to be fully clarified. The gut-liver axis refers to the reciprocal interactions between the gut and the liver, and its homeostasis plays a prominent role in maintaining liver health. It has been recently reported that patients and animals with DILI have a disrupted gut-liver axis, involving altered gut microbiota composition, increased intestinal permeability and lipopolysaccharide translocation, decreased short-chain fatty acids production, and impaired bile acid metabolism homeostasis. The present review will summarize the evidence from both clinical and preclinical studies about the role of the gut-liver axis in the pathogenesis of DILI. Moreover, we will focus attention on the potential therapeutic strategies for DILI based on improving gut-liver axis function, including herbs and phytochemicals, probiotics, fecal microbial transplantation, postbiotics, bile acids, and Farnesoid X receptor agonists.

Compound chenpi tea consumption reduces obesity-related metabolic disorders by modulating gut microbiota and serum metabolites in mice

BACKGROUND

Compound chenpi tea (CCT) is a popular herbal beverage made from citri reticulatae pericarpium, Ganoderma lucidum, and pu-erh tea. This study aimed to investigate the anti-obesity effect of CCT in mice fed a high-fat diet (HFD) and to explore the potential mediators by 16S ribosomal RNA sequencing and serum metabolomic analysis.

RESULTS

The results showed that CCT supplementation can effectively reduce diet-induced obesity, hepatic steatosis, dyslipidemia, and insulin resistance. Further analyses revealed that CCT could reverse the changes of 28 metabolites induced by HFD, mainly affecting, amino acid metabolism, gut microbiota metabolism, and glycerophospholipid metabolism. CCT could also alleviate the intestinal dysbiosis by decreasing the abundance of Romboutsia, Gemella, [Eubacterium]_fissicatena_group, and Faecalibaculum, and increasing the abundance of Oscillibacter, Blautia, and Acetatifactor.

CONCLUSION

Collectively, these findings demonstrated that CCT supplementation modulated gut microbiota and obesity-related metabolic disorders in mice. © 2023 Society of Chemical Industry.

Curcumin Mitigates the High-Fat High-Sugar Diet-Induced Impairment of Spatial Memory, Hepatic Metabolism, and the Alteration of the Gut Microbiome in Alzheimer's Disease-Induced (3xTg-AD) Mice

The escalating prevalence of metabolic diseases and an aging demographic has been correlated with a concerning rise in Alzheimer's disease (AD) incidence. This study aimed to access the protective effects of curcumin, a bioactive flavonoid from turmeric, on spatial memory, metabolic functions, and the regulation of the gut microbiome in AD-induced (3xTg-AD) mice fed with either a normal chow diet (NCD) or a high-fat high-sugar diet (HFHSD). Our findings revealed an augmented susceptibility of the HFHSD-fed 3xTg-AD mice for weight gain and memory impairment, while curcumin supplementation demonstrated a protective effect against these changes. This was evidenced by significantly reduced body weight gain and improved behavioral and cognitive function in the curcumin-treated group. These improvements were substantiated by diminished fatty acid synthesis, altered cholesterol metabolism, and suppressed adipogenesis-related pathways in the liver, along with modified synaptic plasticity-related pathways in the brain. Moreover, curcumin enriched beneficial gut microbiota, including Oscillospiraceae and Rikenellaceae at the family level, and Oscillibacter, Alistipes, Pseudoflavonifractor, Duncaniella, and Flintibacter at the genus level. The observed alteration in these gut microbiota profiles suggests a potential crosswalk in the liver and brain for regulating metabolic and cognitive functions, particularly in the context of obesity-associated cognitive disfunction, notably AD.

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.

Unveiling the role of gut dysbiosis in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial complicated condition, reflected by the accumulation of extra fat in the liver. A detailed study of literature throws light on the fascinating connection between gut dysbiosis and NAFLD. The term 'gut dysbiosis' describes an imbalance in the harmony and operation of the gut microflora, which can upshoot a number of metabolic disorders. To recognize the underlying mechanisms and determine treatment options, it is essential to comprehend the connection between gut dysbiosis and NAFLD. This in-depth review discusses the normal gut microflora composition and its role in health, alterations in the gut microflora composition that leads to disease state focusing on NAFLD. The potential mechanisms influencing the advent and aggravation of NAFLD suggested disturbance of microbial metabolites, changes in gut barrier integrity, and imbalances in the composition of the gut microflora. Furthermore, it was discovered that gut dysbiosis affected immune responses, liver inflammation, and metabolic pathways, aggravating NAFLD.

Gut microbiota regulates circadian oscillation in hepatic ischemia-reperfusion injury-induced cognitive impairment by interfering with hippocampal lipid metabolism in mice

BACKGROUND

Hepatic ischemia-reperfusion injury (HIRI) is a common complication of liver surgery, which can lead to extrahepatic metabolic disorders, such as cognitive impairment. Recent observations have emphasized the critical effects of gut microbial metabolites in regulating the development of liver injury. Herein, we investigated the potential contribution of gut microbiota to HIRI-related cognitive impairment.

METHODS

HIRI murine models were established by ischemia-reperfusion surgery in the morning (ZT0, 08:00) and evening (ZT12, 20:00), respectively. Antibiotic-induced pseudo-germ-free mice were gavaged with fecal bacteria of the HIRI models. Behavioral test was used to assess cognitive function. 16S rRNA gene sequencing and metabolomics were used for microbial and hippocampal analysis.

RESULTS

Our results established that cognitive impairment caused by HIRI underwent diurnal oscillations; HIRI mice performed poorly on the Y-maze test and the novel object preference test when surgery occurred in the evening compared with the morning. In addition, fecal microbiota transplantation (FMT) from the ZT12-HIRI was demonstrated to induce cognitive impairment behavior. The specific composition and metabolites of gut microbiota were analyzed between the ZT0-HIRI and ZT12-HIRI, and bioinformatic analysis showed that the differential fecal metabolites were significantly enriched in lipid metabolism pathways. After FMT, the hippocampal lipid metabolome between the P-ZT0-HIRI and P-ZT12-HIRI groups was analyzed to reveal a series of lipid molecules with significant differences.

CONCLUSIONS

Our findings indicate that gut microbiota are involved in circadian differences of HIRI-related cognitive impairment by affecting hippocampal lipid metabolism.

Effects of different processed tomatoes on carotenoid release and microbiota composition during in vitro gastrointestinal digestion and colonic fermentation

Carotenoids in tomatoes confer significant health benefits to humans but with the disadvantage of the carotenoids from raw tomatoes not being easily absorbed for utilization. Thus, this study aimed to investigate the effects of different cooking processes on carotenoid release and human gut microbiota composition during in vitro simulated gastrointestinal digestion of tomatoes. The results showed that stir-frying significantly increased the release of lycopene and β-carotene during gastrointestinal digestion, with boiling being the second most effective treatment. The boiling-treated tomatoes enhanced the carotenoid release during in vitro fermentation. Gut microbiota analysis revealed that the digestion of the raw and boiled tomatoes promoted the growth of potentially beneficial microbiota while reducing the ratio of Firmicutes/Bacteroides, which potentially helps prevent obesity. Boiling treatment significantly reduced the growth of Peptostreptococcus and was negatively correlated with carotenoid release. Overall, the boiling-treated tomatoes were more effective than the raw or stir-fried tomatoes in terms of both colon health benefits and carotenoid release.

Cadmium exposure dysregulates purine metabolism and homeostasis across the gut-liver axis in a mouse model

Cadmium (Cd) exposure has been associated with the development of enterohepatic circulation disorders and hyperuricemia, but the possible contribution of chronic low-dose Cd exposure to disease progression is still need to be explored. A mouse model of wild-type mice (WT) and Uox-knockout mice (Uox-KO) to find out the toxic effects of chronic low-dose Cd exposure on liver purine metabolism by liquid chromatography-mass spectrometry (LC-MS) platform and associated intestinal flora. High throughput omics analysis including metabolomics and transcriptomics showed that Cd exposure can cause disruption of purine metabolism and energy metabolism. Cd changes several metabolites associated with purine metabolism (xanthine, hypoxanthine, adenosine, uridine, inosine) and related genes, which are associated with elevated urate levels. Microbiome analysis showed that Cd exposure altered the disturbance of homeostasis in the gut. Uox-KO mice were more susceptible to Cd than WT mice. Our findings extend the understanding of potential toxicological interactions between liver and gut microbiota and shed light on the progression of metabolic diseases caused by Cd exposure.

Gut ecological networks reveal associations between bacteria, exercise, and clinical profile in non-alcoholic fatty liver disease patients

IMPORTANCE

Our study is applying a community-based approach to examine the influence of exercise on gut microbiota (GM) and discover GM structures linked with NAFLD improvements during exercise. The majority of microbiome research has focused on finding specific species that may contribute to the development of human diseases. However, we believe that complex diseases, such as NAFLD, would be more efficiently treated using consortia of species, given that bacterial functionality is based not only on its own genetic information but also on the interaction with other microorganisms. Our results revealed that exercise significantly changes the GM interaction and that structural alterations can be linked with improvements in intrahepatic lipid content and metabolic functions. We believe that the identification of these characteristics in the GM enhances the development of exercise treatment for NAFLD and will attract general interest in this field.

Identification of Diagnostic Biomarkers for Compensatory Liver Cirrhosis Based on Gut Microbiota and Urine Metabolomics Analyses

Liver cirrhosis is one of the most prevalent chronic liver disorders with high mortality. We aimed to explore changed gut microbiome and urine metabolome in compensatory liver cirrhosis (CLC) patients, thus providing novel diagnostic biomarkers for CLC. Forty fecal samples from healthy volunteers (control: 19) and CLC patients (patient: 21) were undertaken 16S rDNA sequencing. Chromatography-mass spectrometry was performed on 40 urine samples (20 controls and 20 patients). Microbiome and metabolome data were separately analyzed using corresponding bioinformatics approaches. The diagnostic model was constructed using the least absolute shrinkage and selection operator regression. The optimal diagnostic model was determined by five-fold cross-validation. Pearson correlation analysis was applied to clarify the relations among the diagnostic markers. 16S rDNA sequencing analyses showed changed overall alpha diversity and beta diversity in patient samples compared with those of controls. Similarly, we identified 841 changed metabolites. Pathway analysis revealed that the differential metabolites were mainly associated with pathways, such as tryptophan metabolism, purine metabolism, and steroid hormone biosynthesis. A 9-maker diagnostic model for CLC was determined, including 7 microorganisms and 2 metabolites. In this model, there were multiple correlations between microorganisms and metabolites. Subdoligranulum, Agathobacter, norank_f_Eubacterium_coprostanoligenes_group, Butyricicoccus, Lachnospiraceae_UCG_004, and L-2,3-Dihydrodipicolinate were elevated in CLC patients, whereas Blautia, Monoglobus, and 5-Acetamidovalerate were reduced. A novel diagnostic model for CLC was constructed and verified to be reliable, which provides new strategies for the diagnosis and treatment of CLC.

Gut microbiota disorder induces liver dysfunction in polycystic ovary syndrome rats' model by regulating metabolite rosmarinic acid

AIMS

The present study aims to investigate the impact of the gut microbiota and serum metabolites on the regulation of liver dysfunction in PCOS.

MATERIALS AND METHODS

PCOS rat models were established by treating Sprague Dawley (SD) rats with DHEA (an androgen, 60 mg/kg) and LET (a nonsteroidal aromatase inhibitor, 1 mg/kg) for 90 days. Hematoxylin and eosin staining (H&E), Western blotting, and radioimmunoassay were employed to test ovarian and liver functions. Gut microbiome and serum metabolites were assessed using 16S rRNA amplicon sequencing and non-targeted metabolomics, respectively. The association between gut microbiota and serum metabolites was examined using Spearman analysis. Finally, using HepG2 cells to investigate the function of the serum metabolite rosmarinic acid (RA).

KEY FINDINGS

Both Dehydroepiandrosterone (DHEA) and letrozole (LET) treatments induced a PCOS phenotype and liver dysfunction. However, LET resulted in more severe lipid accumulation and liver cell apoptosis than DHEA. 16S rRNA sequencing and non-targeted metabolomics analysis revealed significant differences in beta diversity and serum metabolite profiles among the three groups. Furthermore, among the significantly changed metabolites, RA was found to have a significant correlation with the levels of serum aspartate transaminase (AST) and lactate dehydrogenase (LDH) and could promote HepG2 cell apoptosis.

SIGNIFICANCE

Restoring gut microbiota, altering serum metabolites and/or decreasing RA may provide a new insight to treat this complication.

ENPP2 inhibitor improves proliferation in AOM/DSS-induced colorectal cancer mice via remodeling the gut barrier function and gut microbiota composition

In our previous multicenter study, we delineated the inherent metabolic features of colorectal cancer (CRC). Therein, we identified a member of the ectonucleotide pyrophosphatase/ phosphodiesterase family (ENPP2) as a significant differential metabolite of CRC. In this study, the role of ENPP2 in CRC has been demonstrated using established in vitro and in vivo models including ENPP2 gene knockdown, and use of the ENPP2 inhibitor, GLPG1690. We found that CRC proliferation was decreased after either ENPP2 gene knockdown or use of ENPP2 inhibitors. We further evaluated the role of GLPG1690 in AOM/DSS-induced CRC mice via intestinal barrier function, macrophage polarization, inflammatory response and microbial homeostasis. Results of immunofluorescence staining and Western blotting showed that GLPG1690 can restore gut-barrier function by increasing the expression of tight junction proteins, claudin-1, occludin and ZO-1. M2 tumor-associated macrophage polarization and colonic inflammation were attenuated after treatment with GLPG1690 using the Azoxymethane/Dextran Sodium Sulfate (AOM/DSS) model. Moreover, 16 S rDNA pyrosequencing and metagenomic analysis showed that GLPG1690 could alleviate gut dysbiosis in mice. Furthermore, administration of GLPG1690 with antibiotics as well as fecal microbiota transplantation assays demonstrated a close link between the efficacy of GLPG1690 and the gut microbiota composition. Finally, results of metabolomic analysis implicated mainly the gut microbiota-derived metabolites of aromatic amino acids in CRC progression. These findings may provide novel insights into the development of small-molecule ENPP2 inhibitors for the treatment of CRC.

Current Therapeutical Approaches Targeting Lipid Metabolism in NAFLD

Nonalcoholic fatty liver disease (NAFLD, including nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH)) is a high-prevalence disorder, affecting about 1 billion people, which can evolve to more severe conditions like cirrhosis or hepatocellular carcinoma. NAFLD is often concomitant with conditions of the metabolic syndrome, such as central obesity and insulin-resistance, but a specific drug able to revert NAFL and prevent its evolution towards NASH is still lacking. With the liver being a key organ in metabolic processes, the potential therapeutic strategies are many, and range from directly targeting the lipid metabolism to the prevention of tissue inflammation. However, side effects have been reported for the drugs tested up to now. In this review, different approaches to the treatment of NAFLD are presented, including newer therapies and ongoing clinical trials. Particular focus is placed on the reverse cholesterol transport system and on the agonists for nuclear factors like PPAR and FXR, but also drugs initially developed for other conditions such as incretins and thyromimetics along with validated natural compounds that have anti-inflammatory potential. This work provides an overview of the different therapeutic strategies currently being tested for NAFLD, other than, or along with, the recommendation of weight loss.

Alterations in the gut microbiota and the efficacy of adjuvant probiotic therapy in liver cirrhosis

Background

Liver cirrhosis is the end stage of various chronic liver diseases (CLDs). The gut microbiota can impact the liver environment and trigger chronic liver inflammation through the gut-liver axis. Alteration of the gut microbiota has become an effective strategy in the biological treatment of cirrhosis.

Methods

Twenty-eight patients with liver cirrhosis and 16 healthy individuals were included, and fresh stool samples were collected. We analyzed changes in the gut microbiota between groups by 16S rRNA sequencing and evaluated the association between microbiota alterations and hepatic function. Additionally, 102 cirrhotic patients were retrospectively enrolled and divided into a probiotic group (n=44) and a nonprobiotic group (n=58) in addition to standard treatment for cirrhosis. Patients were monitored for hematological parameters and hepatic function during the six-month follow-up.

Results

The gut microbiota profile of patients with cirrhosis was greatly different from that of healthy individuals, presenting with significantly reduced α diversity and decreased abundance of representative SCFA-producing bacteria including Firmicutes, Coprococcus and Clostridium IV. The pathogenic bacteria Gammaproteobacteria, Veillonella, and Bacilli were greatly enriched in cirrhotic patients. Additionally, patients with decompensated cirrhosis (DCPC) had a significantly reduced abundance of Oscillibacter compared to compensated cirrhosis (CPC), which is also a SCFA-producing bacteria, and the lower Firmicutes to Bacteroidetes ratio and enhanced MDR values were also shown in DCPC patients compared to CPC patients. In addition, the abundance of Firmicutes was negatively related to hepatic function in cirrhotic patients, including the levels of ALT, AST, and DBIL. From the retrospective study, we found that biochemical improvements in alanine transaminase (ALT) and total bilirubin (TBIL) were obtained in DCPC patients who received oral probiotic therapy compared with the nonprobiotic group.

Conclusion

Severe microbial dysbiosis existed in patients with liver cirrhosis, especially patients who reached the decompensatory stage. SCFA-producing bacteria were significantly reduced in cirrhosis. Altered gut microbiota cause changes in functional modules, which may contribute to cirrhosis progression and are associated with clinical prognosis. Adjuvant probiotic supplementation to enhance SCFA-producing bacteria can be a prospective therapy for patients with cirrhosis.

Investigating causal associations among gut microbiota, metabolites, and liver diseases: a Mendelian randomization study

Objective

There is some evidence for an association between gut microbiota and nonalcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), and viral hepatitis, but no studies have explored their causal relationship.

Methods

Instrumental variables of the gut microbiota (N = 13266) and gut microbiota-derived metabolites (N = 7824) were acquired, and a Mendelian randomization study was performed to explore their influence on NAFLD (1483 European cases and 17,781 European controls), ALD (2513 European cases and 332,951 European controls), and viral hepatitis risk (1971 European cases and 340,528 European controls). The main method for examining causality is inverse variance weighting (IVW).

Results

IVW results confirmed that Anaerotruncus (p = 0.0249), Intestinimonas (p = 0.0237), Lachnoclostridium (p = 0.0245), Lachnospiraceae NC2004 group (p = 0.0083), Olsenella (p = 0.0163), and Peptococcus (p = 0.0472) were protective factors for NAFLD, and Ruminococcus 1 (p = 0.0120) was detrimental for NAFLD. The higher abundance of three genera, Lachnospira (p = 0.0388), Desulfovibrio (p = 0.0252), and Ruminococcus torques group (p = 0.0364), was correlated with a lower risk of ALD, while Ruminococcaceae UCG 002 level was associated with a higher risk of ALD (p = 0.0371). The Alistipes (p = 0.0069) and Ruminococcaceae NK4A214 group (p = 0.0195) were related to a higher risk of viral hepatitis. Besides, alanine (p = 0.0076) and phenyllactate (p = 0.0100) were found to be negatively correlated with NAFLD, while stachydrine (Op = 0.0244) was found to be positively associated with NAFLD. The phenylacetate (p = 0.0353) and ursodeoxycholate (p = 0.0144) had a protective effect on ALD, while the threonate (p = 0.0370) exerted a detrimental influence on ALD. The IVW estimates of alanine (p = 0.0408) and cholate (p = 0.0293) showed their suggestive harmful effects against viral hepatitis, while threonate (p = 0.0401) displayed its suggestive protective effect against viral hepatitis.

Conclusion

In conclusion, our research supported causal links between the gut microbiome and its metabolites and NAFLD, ALD, and viral hepatitis.

Association between Gut Microbiota and Digestive System Cancers: A Bidirectional Two-Sample Mendelian Randomization Study

Accumulating evidence indicates that gut microbiota closely correlates with the tumorigenesis of digestive system cancers (DSCs). However, whether the causality between gut microbiota and DSCs exists is unknown. Genome-wide association study (GWAS) summary statistics for gut microbiota and DSCs and the bidirectional two-sample Mendelian randomization (MR) analysis were utilized to assess the causality between gut microbiota and DSCs. Sensitivity analyses were performed to evaluate the robustness of our results. We found that the genus Eggerthella (OR = 0.464, 95%CI: 0.27 to 0.796, p = 0.005) was negatively associated with the risk of gastric cancer. The genetically predicted genus Lachnospiraceae FCS020 group (OR = 0.607, 95%CI: 0.439 to 0.84, p = 0.003) correlated with a lower risk of colorectal cancer, and genus Turicibacter (OR = 0.271, 95%CI: 0.109 to 0.676, p = 0.005) was a protective factor for liver cancer. In the reverse MR, DSCs regulated the relative abundance of specific strains of gut microbiota. We comprehensively screened the association between gut microbiota and DSCs using a bidirectional two-sample MR analysis and identified the causality between several microbial taxa and DSCs. Our discoveries are beneficial for the development of novel microbial markers and microbiota-modifying therapeutics for DSC patients.

Aqueous extract of Polygala japonica Houtt. ameliorated nonalcoholic steatohepatitis in mice through restoring the gut microbiota disorders and affecting the metabolites in feces and liver

BACKGROUND

Polygala japonica Houtt. (PJ) has been demonstrated with several biological potentials such as lipid-lowering and anti-inflammatory effects. However, the effects and mechanisms of PJ on nonalcoholic steatohepatitis (NASH) remain unclear.

PURPOSE

The aim of this study was to evaluate the effects of PJ on NASH and illustrate the mechanism based on modulating gut microbiota and host metabolism.

MATERIALS AND METHODS

NASH mouse model was induced using methionine and choline deficient (MCD) diet and orally treated with PJ. The therapeutic, anti-inflammatory, and anti-oxidative effects of PJ on mice with NASH were firstly assessed. Then, the gut microbiota of mice was analyzed using 16S rRNA sequencing to assess the changes. Finally, the effects of PJ on the metabolites in liver and feces were explored by untargeted metabolomics.

RESULTS

The results indicated that PJ could improve hepatic steatosis, liver injury, inflammatory response, and oxidative stress in NASH mice. PJ treatment also affected the diversity of gut microbiota and changed the relative abundances of Faecalibaculum. Lactobacillus, Muribaculaceae, Dubosiella, Akkermansia, Lachnospiraceae_NK4A136_group, and Turicibacter in NASH mice. In addition, PJ treatment modulated 59 metabolites both in liver and feces. Metabolites involved in histidine, and tryptophan metabolism pathways were identified as the key metabolites according to the correlation analysis between differential gut microbiota and metabolites.

CONCLUSION

Our study demonstrated the therapeutic, anti-inflammatory and anti-oxidative potentials of PJ on NASH. The mechanisms of PJ treatment were related to the improvement of gut microbiota dysbiosis and the regulation of histidine and tryptophan metabolism.

Impaired flux of bile acids from the liver to the gut reveals microbiome-immune interactions associated with liver damage

Currently, there is evidence that alteration in the gut ecosystem contributes to the development of liver diseases, however, the complex mechanisms involved are still unclear. We induced cholestasis in mice by bile duct ligation (BDL), mirroring the phenotype of a bile duct obstruction, to understand how gut microbiota alterations caused by an impaired flow of bile acid to the gut contribute to the pathogenesis and progression of liver disease. We performed longitudinal stool, heart, and liver sampling using mice receiving BDL and controls receiving sham operation (ShamOP). Shotgun metagenomics profiling using fecal samples taken before and on day 1, day 3, and day 7 after surgery was performed, and the cytokines and clinical chemistry profiles from heart blood, as well as the liver bile acids profile, were measured. The BDL surgery reshaped the microbiome of mice, resulting in highly distinct characteristics compared to the ShamOP. Our analysis of the microbiome pathways and ECs revealed that BDL reduces the production of hepatoprotective compounds in the gut, such as biotin, spermidine, arginine, and ornithine, which were negatively associated with inflammatory cytokines (IL-6, IL-23, MCP-1). The reduction of the functional potential of the gut microbiota in producing those hepatoprotective compounds is associated with the decrease of beneficial bacteria species from Anaerotruncus, Blautia, Eubacterium, and Lachnoclostridium genera, as well as the increase of disease-associated bacteria e.g., Escherichia coli and Entercoccus faecalis. Our findings advances our knowledge of the gut microbiome-bile acids-liver triangle, which may serve as a potential therapeutic strategy for liver diseases.

Membrane Vesicles of Toxigenic Clostridioides difficile Affect the Metabolism of Liver HepG2 Cells

Clostridioides difficile infection (CDI) appears to be associated with different liver diseases. C. difficile secretes membrane vesicles (MVs), which may be involved in the development of nonalcoholic fatty liver disease (NALFD) and drug-induced liver injury (DILI). In this study, we investigated the presence of C. difficile-derived MVs in patients with and without CDI, and analyzed their effects on pathways related to NAFLD and DILI in HepG2 cells. Fecal extracellular vesicles from CDI patients showed an increase of Clostridioides MVs. C. difficile-derived MVs that were internalized by HepG2 cells. Toxigenic C. difficile-derived MVs decreased mitochondrial membrane potential and increased intracellular ROS compared to non-toxigenic C. difficile-derived MVs. In addition, toxigenic C. difficile-derived MVs upregulated the expression of genes related to mitochondrial fission (FIS1 and DRP1), antioxidant status (GPX1), apoptosis (CASP3), glycolysis (HK2, PDK1, LDHA and PKM2) and β-oxidation (CPT1A), as well as anti- and pro-inflammatory genes (IL-6 and IL-10). However, non-toxigenic C. difficile-derived MVs did not produce changes in the expression of these genes, except for CPT1A, which was also increased. In conclusion, the metabolic and mitochondrial changes produced by MVs obtained from toxigenic C. difficile present in CDI feces are common pathophysiological features observed in the NAFLD spectrum and DILI.

Fu brick tea alleviates high fat induced non-alcoholic fatty liver disease by remodeling the gut microbiota and liver metabolism

Fu brick tea (FBT) and its extracts have good lipid-lowering effects and have been used in the treatment of obesity in previous studies. Unfortunately, the therapeutic effect of FBT on non-alcoholic fatty liver disease (NAFLD) has not been thoroughly studied. In this study, we explored the mechanism by which FBT alleviates NAFLD from the perspective of the gut microbiota and liver metabolites. The results showed that FBT could reduce the body weight, liver weight and abdominal fat of NAFLD mice, and improve liver pathological morphology, liver lipid deposition, blood lipids and liver function. Moreover, FBT improved the diversity of the gut microbiota and changed the profile of liver metabolism in NAFLD mice. Further studies showed that FBT could ameliorate the cecum barrier, and regulate the effects of factors related to lipid synthesis in the cecum and liver of NAFLD mice. In conclusion, the present study confirmed that FBT can alleviate high fat induced NAFLD by regulating the homeostasis of the gut microbiota and liver metabolites.

Nutritional Support in Acute Liver Failure

Acute liver failure (ALF) presents with an acute abnormality of liver blood tests in an individual without underlying chronic liver disease. The clinical course leads to the development of coagulopathy and hepatic encephalopathy. The role of nutrition in its prevention and treatment remains uncertain. We aimed to review literature data on the concept of ALF and the role of nutrition in its treatment and prevention, considering the impact of gut microbiota dysbiosis and eubiosis. We conducted a review of the literature on the main medical databases using the following keywords and acronyms and their associations: liver failure, nutrition, branched-chain amino acids, gut microbiota, dysbiosis, and probiotics. Upon their arrival at the emergency department, an early, accurate nutritional assessment is crucial for individuals with ALF. Branched-chain amino acids (BCAAs), stable euglycemia maintenance, and moderate caloric support are crucial for this subset of patients. An excessive protein load must be avoided because it worsens hepatic encephalopathy. Preclinical evidence supports future probiotics use for ALF treatment/prevention. Nutritional support and treatment for ALF are crucial steps against patient morbidity and mortality. BCAAs and euglycemia remain the mainstay of nutritional treatment of ALF. Gut dysbiosis re-modulation has an emerging and natural-history changing impact on ALF.