Bacterial translocation and changes in the intestinal microbiome in mouse models of liver disease

Ganoderma lucidum spore oil attenuates acute liver injury by modulating lipid metabolism and gut microbiota

The incidence of acute liver injury is increasing and poses a significant threat to human health. Ganoderma lucidum spore oil (GLSO), a lipid substance extracted from Ganoderma lucidum spore powder using supercritical CO2 technology, has been investigated for its potential to prevent acute liver injury. However, the specific mechanism underlying the protective effects of GLSO remains incompletely understood. In this study, we investigated the preventive effect of GLSO on acute liver injury in rats, focusing on the gut microbiome and serum metabolomics. GLSO effectively alleviated liver dysfunction and reduced inflammation, leading to the prevention of acute liver injury in rats. Serum metabolomics analysis revealed that GLSO primarily modulated lipid metabolic pathways related to glycerophospholipid metabolism and sphingolipid metabolism. Specifically, GLSO decreased the levels of metabolites such as lysophosphatidylcholine (LPC), glycerophosphatidylcholine (GPC), and sphinganine 1-phosphate (SA1P), while increasing the levels of phosphatidylglycerol (PG) and digalactosylceramide (DGC). Gut microbiomics data indicated that GLSO effectively regulated the composition of the gut microbiota in rats with acute liver injury. Specifically, it increased the abundance of Firmicutes and decreased the abundance of Proteobacteria. Mantel test correlation analysis revealed a close relationship between gut microbial Burkholderiales and lipid metabolites in GLSO-mediated prevention of acute liver injury. GLSO exerts its preventive effects on acute liver injury by remodeling the gut microbiota and regulating lipid metabolism. These findings provide novel insights and potential directions for the development of new drugs targeting acute liver injury.

Probiotics for the treatment of hyperlipidemia: Focus on gut-liver axis and lipid metabolism

Hyperlipidemia, a metabolic disorder marked by dysregulated lipid metabolism, is a key contributor to the onset and progression of various chronic diseases. Maintaining normal lipid metabolism is critical for health, as disruptions lead to dyslipidemia. The gut and liver play central roles in lipid homeostasis, with their bidirectional communication, known as the gut-liver axis, modulated by bile acids (BAs), gut microbiota, and their metabolites. BAs are essential for regulating their own synthesis, lipid metabolism, and anti-inflammatory responses, primarily through the farnesoid X receptor (FXR) and Takeda G protein-coupled receptor 5 (TGR5). Available evidence suggests that high-fat diet-induced the gut microbiota dysbiosis can induce "leaky gut," allowing toxic microbial metabolites to enter the liver via portal circulation, triggering liver inflammation and lipid metabolism disturbances, ultimately leading to hyperlipidemia. Extensive studies have highlighted the roles of probiotics and Traditional Chinese Medicine (TCM) in restoring gut-liver axis balance and modulating lipid metabolism through regulating the levels of lipopolysaccharides, short-chain fatty acids, and BAs. However, the therapeutic potential of probiotics and TCM for hyperlipidemia remains unclear. Here, firstly, we explore the intricate interplay among gut microbiota and metabolites, lipid metabolism, gut-liver axis, and hyperlipidemia. Secondly, we summarize the mechanisms by which probiotics and TCM can alleviate hyperlipidemia by altering the composition of gut microbiota and regulating lipid metabolism via the gut-liver axis. Finally, we emphasize that more clinical trials of probiotics and TCM are necessary to examine their effects on lipid metabolism and hyperlipidemia.

Mechanisms of sepsis-induced acute liver injury: a comprehensive review

Sepsis is a severe, often life-threatening form of organ dysfunction that arises from an inappropriately regulated host response to infectious pathogen exposure. As the largest gland in the body, the liver serves as a regulatory hub for metabolic, immune, and detoxification activity. It is also an early sepsis target organ such that hepatic dysfunction is observed in 34-46% of patients with sepsis. The precise mechanisms that give rise to sepsis-induced liver injury, however, remain incompletely understood. Based on the research conducted to date, dysregulated systemic inflammation, microbial translocation, microcirculatory abnormalities, cell death, metabolic dysfunction, and liver inflammation may all contribute to the liver damage that can arise in the context of septicemia. This review was developed to provide an overview summarizing the potential mechanisms underlying sepsis-induced liver injury, informing the selection of potential targets for therapeutic intervention and providing a framework for the alleviation of patient symptoms and the improvement of prognostic outcomes.

Impact of Helicobacter pylori on Immune Checkpoint Inhibition in Hepatocellular Carcinoma: A Multicenter Study

INTRODUCTION

Immunomodulating effects of Helicobacter pylori (H. pylori) have been shown to inhibit antitumor immunity. Resistance to immune checkpoint inhibitor (ICI)-based therapies is common among patients with hepatocellular carcinoma (HCC). This study aimed to assess the effect of H. pylori on the outcomes of ICI in patients with HCC.

METHODS

We conducted a multicenter study in patients with HCC across a broad range of treatments. Patients received either ICI-based combination regimens or sorafenib-based therapy. H. pylori serostatus and virulence factors were determined and correlated with overall survival (OS), progression-free survival (PFS), and safety across the treatment modalities.

RESULTS

180 patients with HCC were included; among these, 64 were treated with ICI-based regimen and 116 with sorafenib-based regimen. In patients treated with ICI, median OS was shorter in H. pylori-positive patients (10.9 months in H. pylori-positive vs. 18.3 months; p = 0.0384). H. pylori positivity was associated with a shorter PFS in ICI recipients (3.9 months vs. 6.8 months, p = 0.0499). In patients treated with sorafenib, median OS was not shorter among H. pylori-positive patients (13.4 months in H. pylori-positive vs. 10.6 months; p = 0.3353). Immune-related adverse events and rates of gastrointestinal bleeding were comparable between H. pylori-positive and -negative patients.

CONCLUSION

H. pylori seropositivity was linked to poorer outcomes in patients with HCC treated with ICI. This association was not observed among patients receiving sorafenib-based therapies.

Gut-X axis

Recent advances in understanding the modulatory functions of gut and gut microbiota on human diseases facilitated our focused attention on the contribution of the gut to the pathophysiological alterations of many extraintestinal organs, including the liver, heart, brain, lungs, kidneys, bone, skin, reproductive, and endocrine systems. In this review, we applied the "gut-X axis" concept to describe the linkages between the gut and other organs and discussed the latest findings related to the "gut-X axis," including the underlying modulatory mechanisms and potential clinical intervention strategies.

Gut microbiota shifts in hepatitis B-related portal hypertension after transjugular intrahepatic portosystemic shunt: Mechanistic and clinical implications

In this article, we provide commentary on the recent article by Zhao et al. We focus on the shifts in the gut microbiota of patients with hepatitis B virus (HBV)-associated cirrhosis/portal hypertension (PH) following transjugular intrahepatic portosystemic shunt (TIPS) and the implications for understanding the mechanisms, diagnosis, and treatment. By comparing the gut microbiota composition and dynamic changes before and after TIPS in patients with and without hepatic encephalopathy, the authors found an increase in non-probiotic bacteria in those who developed hepatic encephalopathy post-TIPS, with Morganella species present only in the hepatic encephalopathy group. The gut microbiota changes post-TIPS among patients without the occurrence of hepatic encephalopathy suggest potential therapeutic benefits through prophylactic microbiome therapies. Furthermore, the specific gut microbiota alterations may hold promise to predict the risk of hepatic encephalopathy in individuals undergoing TIPS for HBV-related PH. Despite these promising findings, future studies are needed to address limitations, including a small sample size, a relatively short evaluation period for gut microbiota alterations, the absence of data on dynamic alterations in gut microbiota post-TIPS and their correlation with blood ammonia levels, and the lack of validation in animal models. In conclusion, Zhao et al's study has shed new light on the link of gut microbiota with post-TIPS hepatic encephalopathy, potentially through the intricate gut-liver axis, and has important clinical implications for improving the management of patients with HBV-related PH.

Cigarette smoking and alcohol-related liver disease

China is a major consumer of alcohol and tobacco. Tobacco and alcohol use are closely linked, with up to 90% of alcoholics having a history of tobacco use, and heavy smokers also tending to be alcoholics. Alcohol-related liver disease (ALD), one of the most common and serious complications of chronic alcohol intake, involving hepatic steatosis, hepatitis, hepatic fibrosis, cirrhosis and hepatocellular carcinoma (HCC), has become one of the globally prevalent chronic diseases. An increasing number of studies have focused on the association between smoking and ALD and explored the mechanisms involved. Clinical evidence suggests that smoking has a negative impact on the incidence and severity of fatty liver disease, progression of liver fibrosis, development of HCC, prognosis of patients with advanced liver disease, and alcohol-related liver transplant recipients. The underlying mechanisms are complex and involve different pathophysiological pathways, including free radical exposure, endoplasmic reticulum stress, insulin resistance, and oncogenic signaling. This review discusses the deleterious effects of smoking on ALD patients and the possible underlying mechanisms at several levels. It emphasizes the importance of discouraging smoking among ALD patients. Finally, the pathogenic role of electronic cigarettes, which have emerged in recent years, is discussed, calling for an emphasis on social missions for young people.

Ampelopsis grossedentata tea alleviating liver fibrosis in BDL-induced mice via gut microbiota and metabolite modulation

Liver fibrosis (LF) is a common sequela to diverse chronic liver injuries, leading to rising rates of cirrhosis and hepatocellular carcinoma (HCC). As the medicinal and edible homologous material, traditional teas have exhibited promising applications in the clinical management of liver fibrosis. Here, we generated a liver fibrosis mouse model to explore the potent therapeutic ability of Ampelopsis grossedentata (AG) tea on this condition by multi-omics analysis. The biochemistry results pointed towards mitigated increases of ALT, AST, TBIL, and ALP triggered by BDL in the AG-treated group. Examination using H&E and Sirius Red staining revealed severe liver injuries, inflammation infiltration, amplified fibrosed regions, and the creation of bile ducts, all of which were fallout from BDL. Immunohistochemistry findings also implicated a noteworthy upregulation of the HSC activation marker α-smooth muscle actin (α-SMA) and the fibrosis marker collagen I in the BDL group. However, these symptoms demonstrated a significant improvement in the group treated with 100 mg/kg AG. Findings from the Western Blot test corroborated the prominent elevation of TNF-α, col1a1, α-SMA, and TGF-β, instigated by BDL, while AG treatment meaningfully modulated these proteins. Furthermore, our study underscored the potential involvement of several microbiota, such as Ruminococcaceae UCG-014, Eubacterium Ruminantium, Ruminococcus 1, Christensenellaceae R-7, Acetatifactor, Dubosiella, Parasutterella, Faecalibaculum, and Defluviitaleaceae UCG-011, in the progression of liver fibrosis and the therapeutic efficacy of AG. This investigation shows that during the process of AG ameliorating BDL-induced liver fibrosis, bile acid derivatives such as CDCA, TCDCA, 3-DHC, UCA, DCA, among others, play significant roles. In this study, we identified that several non-bile acid metabolites, such as Deltarasin, Thr-Ile-Arg, etc., are entailed in the process of AG improving liver fibrosis.

Maslinic acid alleviates alcoholic liver injury in mice and regulates intestinal microbiota via the gut-liver axis

BACKGROUND

Maslinic acid (MA), a pentacyclic triterpene acid, is widely distributed in natural plants and mainly found in the fruit and leaves of olives and hawthorn. MA has been reported as having many health-promoting functions, such as anticancer, anti-inflammation and neuroprotective activities. According to previous study, hawthorn extract has certain hepatoprotective effects. However, the detailed mechanism is still unclear, especially the effect of MA on gut microbiota.

RESULTS

Our study reveals that MA effectively counteracts alcohol-induced liver injury and oxidative stress. It mitigates alcohol-induced intestinal barrier damage, reverses increased permeability and reduces translocation of lipopolysaccharide (LPS). This prevents LPS/Toll-like receptor 4 activation, leading to decreased TNF-α and IL-1β production. Furthermore, MA rebalances gut microbiota by reversing harmful bacterial abundance and enhancing beneficial bacteria post-alcohol consumption.

CONCLUSION

MA, through modulation of gut microbiota, alleviates alcohol-induced liver injury via the gut-liver axis. These findings support the potential use of MA as a functional food ingredient for preventing or treating alcoholic liver disease. © 2024 Society of Chemical Industry.

Pulmonary vascular complications of cirrhosis: hepatopulmonary syndrome and portopulmonary hypertension

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH) are two distinct pulmonary vascular complications seen in patients with liver disease and/or portal hypertension. HPS is characterized by disturbed gas exchange and hypoxemia because of intrapulmonary vascular dilatations. POPH is defined by pulmonary arterial hypertension, which might lead to right heart failure. HPS affects up to 30% of patients with end-stage liver disease requiring liver transplantation. POPH is rarer and affects 1-5% of this patient population. If not recognized and left untreated, these disorders result in significant mortality. This review provides an update on HPS and POPH and discusses their clinical characteristics, screening and diagnostic modalities, and management, including the place of liver transplantation.

Dietary dicarbonyl compounds exacerbated immune dysfunction and hepatic oxidative stress under high-fat diets in vivo

High-fat diets (HFDs) predispose to obesity and liver dysfunctions, and α-dicarbonyl compounds (α-DCs) present in highly processed foods are also implicated in relevant pathological processes. However, the synergistic harmful effects of α-DCs co-administered with HFDs remain to be elucidated. In this study, 6-week-old C57BL/6 mice were fed with a HFD co-administered with 0.5% methylglyoxal (MGO)/glyoxal (GO) in water for 8 weeks, and multi-omics approaches were employed to investigate the underlying toxicity mechanisms. The results demonstrated that the MGO intervention with a HFD led to an increased body weight and blood glucose level, accompanied by the biological accumulation of α-DCs and carboxymethyl-lysine, as well as elevated serum levels of inflammatory markers including IL-1β, IL-6, and MIP-1α. Notably, hepatic lesions were observed in the MGO group under HFD conditions, concomitant with elevated levels of malondialdehyde. Transcriptomic analysis revealed enrichment of pathways and differentially expressed genes (DEGs) associated with inflammation and oxidative stress in the liver. Furthermore, α-DC intervention exacerbated gut microbial dysbiosis in the context of a HFD, and through Spearman correlation analysis, the dominant genera such as Fusobacterium and Bacteroides in the MGO group and Colidextribacter and Parabacteroides in the GO group were significantly correlated with a set of DEGs involved in inflammatory and oxidative stress pathways in the liver. This study provides novel insights into the healthy implications of dietary ultra-processed food products in the context of obesity-associated disorders.

Gut microbiome-brain-cirrhosis axis

Cirrhosis is characterized by inflammation, degeneration, and fibrosis of liver tissue. Along with being the most common cause of liver failure and liver transplant, cirrhosis is a significant risk factor for several neuropsychiatric conditions. The most common of these is HE, which is characterized by cognitive and ataxic symptoms, resulting from the buildup of metabolic toxins with liver failure. However, cirrhosis patients also show a significantly increased risk for neurodegenerative diseases such as Alzheimer and Parkinson diseases, and for mood disorders such as anxiety and depression. In recent years, more attention has been played to communication between the ways the gut and liver communicate with each other and with the central nervous system, and the way these organs influence each other's function. This bidirectional communication has come to be known as the gut-liver-brain axis. The gut microbiome has emerged as a key mechanism affecting gut-liver, gut-brain, and brain-liver communication. Clinical studies and animal models have demonstrated the significant patterns of gut dysbiosis when cirrhosis is present, both with or without concomitant alcohol use disorder, and have provided compelling evidence that this dysbiosis also influences the cognitive and mood-related behaviors. In this review, we have summarized the pathophysiological and cognitive effects associated with cirrhosis, links to cirrhosis-associated disruption of the gut microbiome, and the current evidence from clinical and preclinical studies for the modulation of the gut microbiome as a treatment for cirrhosis and associated neuropsychiatric conditions.

Comparing animal well-being between bile duct ligation models

A prevailing animal model currently used to study severe human diseases like obstructive cholestasis, primary biliary or sclerosing cholangitis, biliary atresia, and acute liver injury is the common bile duct ligation (cBDL). Modifications of this model include ligation of the left hepatic bile duct (pBDL) or ligation of the left bile duct with the corresponding left hepatic artery (pBDL+pAL). Both modifications induce cholestasis only in the left liver lobe. After induction of total or partial cholestasis in mice, the well-being of these animals was evaluated by assessing burrowing behavior, body weight, and a distress score. To compare the pathological features of these animal models, plasma levels of liver enzymes, bile acids, bilirubin, and within the liver tissue, necrosis, fibrosis, inflammation, as well as expression of genes involved in the synthesis or transport of bile acids were assessed. The survival rate of the animals and their well-being was comparable between pBDL+pAL and pBDL. However, surgical intervention by pBDL+pAL caused confluent necrosis and collagen depositions at the edge of necrotic tissue, whereas pBDL caused focal necrosis and fibrosis in between portal areas. Interestingly, pBDL animals had a higher survival rate and their well-being was significantly improved compared to cBDL animals. On day 14 after cBDL liver aspartate, as well as alanine aminotransferase, alkaline phosphatase, glutamate dehydrogenase, bile acids, and bilirubin were significantly elevated, but only glutamate dehydrogenase activity was increased after pBDL. Thus, pBDL may be primarily used to evaluate local features such as inflammation and fibrosis or regulation of genes involved in bile acid synthesis or transport but does not allow to study all systemic features of cholestasis. The pBDL model also has the advantage that fewer mice are needed, because of its high survival rate, and that the well-being of the animals is improved compared to the cBDL animal model.

Understanding the links between micro/nanoplastics-induced gut microbes dysbiosis and potential diseases in fish: A review

At present, the quantity of micro/nano plastics in the environment is steadily rising, and their pollution has emerged as a global environmental issue. The tendency of their bioaccumulation in aquatic organisms (especially fish) has intensified people's attention to their persistent ecotoxicology. This review critically studies the accumulation of fish in the intestines of fish through active or passive intake of micro/nano plastics, resulting in their accumulation in intestinal organs and subsequent disturbance of intestinal microflora. The key lies in the complex toxic effect on the host after the disturbance of fish intestinal microflora. In addition, this review pointed out the characteristics of micro/nano plastics and the effects of their combined toxicity with adsorbed pollutants on fish intestinal microorganisms, in order to fully understand the characteristics of micro/nano plastics and emphasize the complex interaction between MNPs and other pollutants. We have an in-depth understanding of MNPs-induced intestinal flora disorders and intestinal dysfunction, affecting the host's systemic system, including immune system, nervous system, and reproductive system. The review also underscores the imperative for future research to investigate the toxic effects of prolonged exposure to MNPs, which are crucial for evaluating the ecological risks posed by MNPs and devising strategies to safeguard aquatic organisms.

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.

Effects of Lactobacillus paracasei N1115 on gut microbial imbalance and liver function in patients with hepatitis B-related cirrhosis

BACKGROUND

Hepatitis B cirrhosis (HBC) is a chronic disease characterized by irreversible diffuse liver damage and aggravated by intestinal microbial imbalance and metabolic dysfunction. Although the relationship between certain single probiotics and HBC has been explored, the impact of the complex ready-to-eat Lactobacillus paracasei N1115 (LP N1115) supplement on patients with HBC has not been determined.

AIM

To compare the changes in the microbiota, inflammatory factor levels, and liver function before and after probiotic treatment in HBC patients.

METHODS

This study included 160 HBC patients diagnosed at the General Hospital of Ningxia Medical University between October 2018 and December 2020. Patients were randomly divided into an intervention group that received LP N1115 supplementation and routine treatment and a control group that received routine treatment only. Fecal samples were collected at the onset and conclusion of the 12-wk intervention period. The structure of the intestinal microbiota and the levels of serological indicators, such as liver function and inflammatory factors, were assessed.

RESULTS

Following LP N1115 intervention, the intestinal microbial diversity significantly increased in the intervention group (P < 0.05), and the structure of the intestinal microbiota was characterized by an increase in the proportions of probiotic microbes and a reduction in harmful bacteria. Additionally, the intervention group demonstrated notable improvements in liver function indices and significantly lower levels of inflammatory factors (P < 0.05).

CONCLUSION

LP N1115 is a promising treatment for ameliorating intestinal microbial imbalance in HBC patients by modulating the structure of the intestinal microbiota, improving liver function, and reducing inflammatory factor levels.

Research reviews and prospects of gut microbiota in liver cirrhosis: a bibliometric analysis (2001-2023)

INTRODUCTION

The gut-liver axis has emerged as a focal point in chronic liver disorders, prompting more research into the role of the gut microbiota in liver cirrhosis. In individuals with liver cirrhosis, changes in the structure and function of the gut microbiota are closely tied to clinical prognosis. However, there is a scarcity of bibliometric evaluations conducted in this particular field.

METHODS

This study is aiming to conduct a complete analysis of the knowledge structure and centers pertaining to gut microbiota in liver cirrhosis using bibliometric methods. Publications on gut microbiota and liver cirrhosis from 2001 to 2023 are sourced from the Web of Science Core Collection. For the bibliometric analysis, we employ VOSviewer, CiteSpace, and the R package "bibliometrix".

RESULTS

Our study encompasses a comprehensive collection of 3109 articles originating from 96 countries, with notable contributions from leading nations such as the United States and China. The quantity of publications concerning the gut microbiota of liver cirrhosis rises annually. The University of California San Diego, Virginia Commonwealth University, Zhejiang University are the primary research institutions. World Journal of Gastroenterology publishes the most papers in this field, while hepatology is the most frequently co-cited journal. These publications come from a total of 15,965 authors, and the most prolific authors are Bajaj Jasmohan S., Schnabl Bernd and Gillevet Patrick M., while the most co-cited authors are Bajaj Jasmohan S., Younossi Zobair M., and Reiner Wiest. In addition, "dysbiosis", "gut microbiota", "intestinal barrier", "fecal microbiota transplantation", and "complement-system" are the primary keywords of research trends in recent years.

DISCUSSION

This study offering a comprehensive insight into the research dynamics surrounding gut microbiota in patients with liver cirrhosis. It delineates the current research frontiers and hotspots, serving as a valuable guide for scholars.

Comparative Pharmacokinetic Study of Rhubarb Anthraquinones in Normal and Nonalcoholic Fatty Liver Disease Rats

BACKGROUND AND OBJECTIVES

Rhubarb anthraquinones contain five main components, that is, rhein, emodin, aloe-emodin, chrysophanol, and physcion, which demonstrate good therapeutic effects on nonalcoholic fatty liver disease (NAFLD). However, research on its pharmacokinetics in NAFLD remains lacking. This study aimed to investigate the pharmacokinetic differences of rhubarb anthraquinones in normal and NAFLD rats.

METHODS

This study developed an NAFLD rat model by high-fat diet feeding for 6 weeks. Normal and NAFLD groups were orally administered different rhubarb anthraquinones doses (37.5, 75, and 150 mg/kg). The concentration of the rhein, emodin, aloe-emodin, chrysophanol, and physcion in plasma was determined by high-performance liquid chromatography-ultraviolet.

RESULTS

The results revealed significant differences in pharmacokinetic behavior between normal and NAFLD rats. Compared with normal rats, NAFLD rats demonstrated significantly increased maximum plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC0 → ∞) of rhubarb anthraquinones (P < 0.05), as well as significantly prolonged time to reach maximum plasma concentration (Tmax), terminal elimination half-life (t1/2), and mean residence time (MRT) of rhubarb anthraquinones (P < 0.05).

CONCLUSIONS

This study indicates significant differences in the pharmacokinetics of rhubarb anthraquinones between the physiological and NAFLD states of rats. Rhubarb anthraquinone demonstrated a longer retention time and slower absorption rate in NAFLD rats and exhibited higher bioavailability and peak concentration. This finding provides important information for guiding the clinical use of rhubarb anthraquinones under pathological conditions.

Portosystemic shunting prevents hepatocellular carcinoma in non-alcoholic fatty liver disease mouse models

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is one of the leading cause of hepatocellular carcinoma (HCC). This association is supported by the translocation of bacteria products into the portal system, which acts on the liver through the gut-liver axis. We hypothesize that portosystemic shunting can disrupt this relationship, and prevent NAFLD-associated HCC.

METHODS

HCC carcinogenesis was tested in C57BL/6 mice fed a high-fat high-sucrose diet (HFD) and injected with diethylnitrosamine (DEN) at two weeks of age, and in double transgenic LAP-tTA and TRE-MYC (LAP-Myc) mice fed a methionine-choline-deficient diet. Portosystemic shunts were established by transposing the spleen to the sub-cutaneous tissue at eight weeks of age.

RESULTS

Spleen transposition led to a consistent deviation of part of the portal flow and a significant decrease in portal pressure. It was associated with a decrease in the number of HCC in both models. This effect was supported by the presence of less severe liver steatosis after 40 weeks, and lower expression levels of liver fatty acid synthase. Also, shunted mice exhibited lower liver oxygen levels, a key factor in preventing HCC as confirmed by the development of less HCCs in mice with hepatic artery ligation.

CONCLUSIONS

The present data show that portosystemic shunting prevents NAFLD-associated HCC, utilizing two independent mouse models. This effect is supported by the development of less steatosis, and a restored liver oxygen level. Portal pressure modulation and shunting deserve further exploration as potential prevention/treatment options for NAFLD and HCC.

Research Models to Mimic Necrotizing Enterocolitis and Inflammatory Bowel Diseases: Focus on Extracellular Vesicles Action

This review focuses on the crucial role of the intestinal epithelium in maintaining intestinal homeostasis and its significance in the pathogenesis of necrotizing enterocolitis (NEC) and inflammatory bowel diseases (IBD). NEC is a devastating neonatal disease, while IBD represents a global healthcare problem with increasing incidence. The breakdown of the intestinal barrier in neonates is considered pivotal in the development and progression of both disorders. This review provides an overview of the current state of in vitro, ex vivo, and animal models to study epithelial injury in NEC and IBD, addressing pertinent questions that engage clinicians and researchers alike. Despite significant advancements in early recognition and aggressive treatment, no single therapy has been conclusively proven effective in reducing the severity of these disorders. Although early interventions have improved clinical outcomes, NEC and IBD continue to impose substantial morbidity, mortality, and economic burdens on affected individuals and society. Consequently, exploring alternative therapeutic options capable of preventing and treating the sequelae of NEC and IBD has become a pressing necessity. In recent decades, extracellular vehicles (EVs) have emerged as a potential solution to modulate the pathogenic mechanism in these multifactorial and complex disorders. Despite the diverse array of proposed models, a comprehensive model to investigate and decelerate the progression of NEC and IBD remains to be established. To bridge the translational gap between preclinical studies and clinical applications, enhancements in the technical development of gut-on-a-chip models and EVs hold considerable promise.

Astragaloside IV ameliorate acute alcohol-induced liver injury in mice via modulating gut microbiota and regulating NLRP3/caspase-1 signaling pathway

PURPOSE

Astragaloside IV (AS-IV) is a natural saponin substance extracted from the plant Radix Astragali with anti-inflammatory, antioxidant, anti-apoptotic, and liver-protecting effects. This study was to evaluate the liver protection effect of AS-IV on mice after acute alcohol stimulation.

MATERIALS AND METHODS

Mice were orally administrated with AS-IV (50, 150, and 500 mg/kg, respectively), and sodium carboxymethyl cellulose (CMC, 50 mg/kg) daily for 7 days, before giving five alcohol-intragastric injections.

RESULTS

Results suggested that the levels of serum ALT and AST, liver SOD, GSH-PX, 4-HNE, and MDA, serum and liver TNF-α, IL-1β, and IL-6, serum lipopolysaccharide (LPS), lipopolysaccharide binding protein (LBP), diamine oxidase (DAO) and Myeloperoxidase (MPO), the mRNA and protein expression of hepatic NLRP3, Caspase-1, IL-1β, and IL-18 were significantly decreased in AS-IV-treated mice compared with the model group. Moreover, the effect of AS-IV on histopathology of liver tissue confirmed its protective function. Furthermore, AS-IV ameliorated the gut microbiota imbalance and adjusted the abundance of the following dysfunctional bacteria closer to the control group: Butyricicoccus, Turicibacter, Akkermansia, Anaerotruncus, and Mucispirillum. A strong correlation between intestinal bacteria and potential biomarkers was found.

CONCLUSION

Together, our findings indicated that AS-IV exert the hepatoprotective effect by modulating the gut microbiota imbalance and regulating NLRP3/Caspase-1 signaling pathway.

Hsa_circ_0072765 knockdown inhibits proliferation, activation and migration in transforming growth factor-beta (TGF-β)-induced hepatic stellate cells (HSCs) by the miR-197-3p/TRPV3 axis

BACKGROUND

Circular RNAs (circRNAs) participate in the progression of diverse human diseases. However, the effects of circRNAs on liver fibrosis are limited. In this study, we aimed to investigate the functions of hsa_circ_0072765 in liver fibrosis.

METHODS

Transforming growth factor-beta (TGF-β)-treated hepatic stellate cells (HSCs) were used as the cell model of liver fibrosis. Quantitative real-time polymerase chain reaction (qRT-PCR) or western blot was performed to determine the expression of hsa_circ_0072765, microRNA-197-3p (miR-197-3p) and transient receptor potential cation channel subfamily V member 3 (TRPV3). 5'-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry analysis and wound-healing assay were conducted to evaluate cell proliferation, cell cycle and migration. HSC activation was assessed by determining the expression of alpha-smooth muscle actin (α-SMA) and type I collagen alpha 1 (Col1A1). Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) were manipulated to analyze the relationship of hsa_circ_0072765, miR-197-3p and TRPV3. The exosome morphology was observed under transmission electron microscopy (TEM).

RESULTS

Hsa_circ_0072765 level was increased in TGF-β-induced HSCs. Hsa_circ_0072765 knockdown inhibited cell proliferation, cell cycle, activation and migration in TGF-β-induced HSCs. Hsa_circ_0072765 sponged miR-197-3p and negatively regulated miR-197-3p expression. MiR-197-3p inhibition reversed the effects of hsa_circ_0072765 knockdown on TGF-β-induced HSC proliferation, cell cycle, activation and migration. In addition, TRPV3 was the target gene of miR-197-3p and miR-197-3p overexpression inhibited TGF-β-treated HSC proliferation, cell cycle, activation and migration by targeting TRPV3. Besides, we found that exosomal hsa_circ_0072765 was increased in TGF-β-treated HSCs.

CONCLUSION

Hsa_circ_0072765 promoted the progression of TGF-β-treated HSCs by decoying miR-197-3p and upregulating TRPV3.

The Future Is Now: Unraveling the Expanding Potential of Human (Necro)Microbiome in Forensic Investigations

The relevance of postmortem microbiological examinations has been controversial for decades, but the boom in advanced sequencing techniques over the last decade is increasingly demonstrating their usefulness, namely for the estimation of the postmortem interval. This comprehensive review aims to present the current knowledge about the human postmortem microbiome (the necrobiome), highlighting the main factors influencing this complex process and discussing the principal applications in the field of forensic sciences. Several limitations still hindering the implementation of forensic microbiology, such as small-scale studies, the lack of a universal/harmonized workflow for DNA extraction and sequencing technology, variability in the human microbiome, and limited access to human cadavers, are discussed. Future research in the field should focus on identifying stable biomarkers within the dominant Bacillota and Pseudomonadota phyla, which are prevalent during postmortem periods and for which standardization, method consolidation, and establishment of a forensic microbial bank are crucial for consistency and comparability. Given the complexity of identifying unique postmortem microbial signatures for robust databases, a promising future approach may involve deepening our understanding of specific bacterial species/strains that can serve as reliable postmortem interval indicators during the process of body decomposition. Microorganisms might have the potential to complement routine forensic tests in judicial processes, requiring robust investigations and machine-learning models to bridge knowledge gaps and adhere to Locard's principle of trace evidence.

The visceral adipose tissue bacterial microbiota provides a signature of obesity based on inferred metagenomic functions

BACKGROUND

Metabolic inflammation mediated obesity requires bacterial molecules to trigger immune and adipose cells leading to inflammation and adipose depot development. In addition to the well-established gut microbiota dysbiosis, a leaky gut has been identified in patients with obesity and animal models, characterized by the presence of a tissue microbiota in the adipose fat pads.

METHODS

To determine its potential role, we sequenced the bacterial 16 S rRNA genes in the visceral adipose depot of patients with obesity. Taking great care (surgical, biochemical, and bioinformatic) to avoid environmental contaminants. We performed statistical discriminant analyses to identify specific signatures and constructed network of interactions between variables.

RESULTS

The data showed that a specific 16SrRNA gene signature was composed of numerous bacterial families discriminating between lean versus patients with obesity and people with severe obesity. The main discriminant families were Burkholderiaceae, Yearsiniaceae, and Xanthomonadaceae, all of which were gram-negative. Interestingly, the Morganellaceae were totally absent from people without obesity while preponderant in all in patients with obesity. To generate hypotheses regarding their potential role, we inferred metabolic pathways from the 16SrRNA gene signatures. We identified several pathways associated with adenosyl-cobalamine previously described to be linked with adipose tissue development. We further identified chorismate biosynthesis, which is involved in aromatic amino-acid metabolism and could play a role in fat pad development. This innovative approach generates novel hypotheses regarding the gut to adipose tissue axis.

CONCLUSIONS

This innovative approach generates novel hypotheses regarding the gut to adipose tissue axis in obesity and notably the potential role of tissue microbiota.

Contribution of gut microbiota to drug-induced liver injury

Drug-induced liver injury (DILI) is caused by various drugs with complex pathogenesis, and diverse clinical and pathological phenotypes. Drugs damage the liver directly through drug hepatotoxicity, or indirectly through drug-mediated oxidative stress, immune injury and inflammatory insult, which eventually lead to hepatocyte necrosis. Recent studies have found that the composition, relative content and distribution of gut microbiota in patients and animal models of DILI have changed significantly. It has been confirmed that gut microbial dysbiosis brings about intestinal barrier destruction and microorganisms translocation, and the alteration of microbial metabolites may cause or aggravate DILI. In addition, antibiotics, probiotics, and fecal microbiota transplantation are all emerging as prospective therapeutic methods for DILI by regulating the gut microbiota. In this review, we discussed how the altered gut microbiota participates in DILI.

Inflammatory Milieu Related to Dysbiotic Gut Microbiota Promotes Tumorigenesis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is an invasive primary liver cancer caused by multiple pathogenic factors and is a significant global health concern. With few effective therapeutic options, HCC is a heterogeneous carcinoma that typically arises in an inflammatory environment. Recent studies have suggested that dysbiotic gut microbiota is involved in hepatocarcinogenesis via multiple mechanisms. In this review, we discuss the effects of gut microbiota, microbial components, and microbiota-derived metabolites on the promotion and progression of HCC by feeding a persistent inflammatory milieu. In addition, we discuss the potential therapeutic modalities for HCC targeting the inflammatory status induced by gut microbiota. A better understanding of the correlation between the inflammatory milieu and gut microbiota in HCC may be beneficial for developing new therapeutic strategies and managing the disease.

Pathogenesis of Alcoholic Fatty Liver a Narrative Review

Alcohol effect hepatic lipid metabolism through various mechanisms, leading synergistically to an accumulation of fatty acids (FA) and triglycerides. Obesity, as well as dietary fat (saturated fatty acids (FA) versus poly-unsaturated fatty acids (PUFA)) may modulate the hepatic fat. Alcohol inhibits adenosine monophosphate activated kinase (AMPK). AMPK activates peroxisome proliferator activated receptor a (PPARα) and leads to a decreased activation of sterol regulatory element binding protein 1c (SRABP1c). The inhibition of AMPK, and thus of PPARα, results in an inhibition of FA oxidation. This ß-oxidation is further reduced due to mitochondrial damage induced through cytochrome P4502E1 (CYP2E1)-driven oxidative stress. Furthermore, the synthesis of FAs is stimulated through an activation of SHREP1. In addition, alcohol consumption leads to a reduced production of adiponectin in adipocytes due to oxidative stress and to an increased mobilization of FAs from adipose tissue and from the gut as chylomicrons. On the other side, the secretion of FAs via very-low-density lipoproteins (VLDL) from the liver is inhibited by alcohol. Alcohol also affects signal pathways such as early growth response 1 (Egr-1) associated with the expression of tumour necrosis factor α (TNF α), and the mammalian target of rapamycin (mTOR) a key regulator of autophagy. Both have influence the pathogenesis of alcoholic fatty liver. Alcohol-induced gut dysbiosis contributes to the severity of ALD by increasing the metabolism of ethanol in the gut and promoting intestinal dysfunction. Moreover, pathogen-associated molecular patterns (PAMPS) via specific Toll-like receptor (TLR) bacterial overgrowth leads to the translocation of bacteria. Endotoxins and toxic ethanol metabolites enter the enterohepatic circulation, reaching the liver and inducing the activation of the nuclear factor kappa-B (NFκB) pathway. Pro-inflammatory cytokines released in the process contribute to inflammation and fibrosis. In addition, cellular apoptosis is inhibited in favour of necrosis.

Patterns of Circulating Microbiota during the Acute Phase Following ST-Segment Elevation Myocardial Infarction Predict Long-Term Cardiovascular Events

Limited information exists regarding whether circulating microbiota could predict long-term clinical outcomes following ST-segment elevation myocardial infarction (STEMI). A total of 244 consecutive patients with STEMI were followed for 2.8 years, and 64 first major adverse cardiovascular events (MACEs) were recorded. Both microbiota abundance [Corynebacterium tuberculostearicum (HR, 1.28; 95% CI, 1.03-1.58) and Staphylococcus aureus (S. aureus) (HR, 1.16; 95% CI, 1.02-1.33) ] and microbiota clusters (Cluster 2 versus Cluster 1: HR, 1.84; 95% CI, 1.04-3.27) could independently predict MACE. Furthermore, a model based on established independent predictors alone was significantly improved by the addition of different microbiota patterns. In addition, CD14⁺⁺CD16⁺ monocytes (Mon2) had a significant mediation effect on the microbiota patterns → MACE association. The present study demonstrated that the abundance and clusters of circulating microbiota are associated with future adverse cardiovascular events independent of traditional risk factors, which were partially mediated by an increase in Mon2.

The Early Impact of Diets Enriched with Saturated and Unsaturated Fatty Acids on Intestinal Inflammation and Tight Junctions

The gut has been suggested as the first organ to be affected by unbalanced diets contributing to the obesogenic process. This study aimed to test a short time-course exposition model to a known pro- or anti-inflammatory enriched fatty diet to understand the early gut alterations. Male mice were exposed to the chow diet (CT), high-fat (HF) diet, or a high-fat diet partially replaced on flaxseed oil (FS), rich in omega-3 (ω3), for 14 days. HF and FS increased the total body weight mass compared with the CT group, but FS reduced the epididymal fat depot compared to HF. The bioinformatics from mice and human databases showed the Zo1-Ocln-Cldn7 tight junctions as the main protein-triad. In the ileum, the HF diet has increased IL1β transcript and IL1β, TNFα, and CD11b proteins, but reduced the tight junctions (Zo1, Ocln, and Cld7) compared to the CT group. Despite the FS diet being partially efficient in protecting the ileum against inflammation, the tight junctions were increased, compared to the HF group. The GPR120 and GPR40 receptors were unaffected by diets, but GPR120 was co-localized on the surface of ileum macrophages. The short period of a high-fat diet was enough to start the obesogenic process, ileum inflammation, and reduce the tight junctions. Flaxseed oil did not protect efficiently against dysmetabolism. Still, it increased the tight junctions, even without alteration on inflammatory parameters, suggesting the protection against gut permeability during early obesity development.

Alcohol-associated bowel disease: new insights into pathogenesis

Excessive alcohol drinking can cause pathological changes including carcinogenesis in the digestive tract from mouth to large intestine, but the underlying mechanisms are not fully understood. In this review, we discuss the effects of alcohol on small and large intestinal functions, such as leaky gut, dysbiosis and alterations of intestinal epithelium and gut immune dysfunctions, commonly referred to as alcohol-associated bowel disease (ABD). To date, detailed mechanistic insights into ABD are lacking. Accumulating evidence suggests a pathogenic role of ethanol metabolism in dysfunctions of the intestinal tract. Ethanol metabolism generates acetaldehyde and acetate, which could potentially promote functional disruptions of microbial and host components of the intestinal barrier along the gastrointestinal tract. The potential involvement of acetaldehyde and acetate in the pathogenesis of the underlying ABD, including cancer, is discussed. We also highlight some gaps in knowledge existing in the field of ABD. Finally, we discuss future directions in exploring the role of acetaldehyde and acetate generated during chronic alcohol intake in various pathologies affecting different sites of the intestinal tract.

Current clinical understanding and effectiveness of portopulmonary hypertension treatment

Portopulmonary hypertension (PoPH) is a rare subtype of Group 1 pulmonary arterial hypertension (PAH) with a poor prognosis. According to the most up-to-date definition, PoPH is characterized by a mean pulmonary arterial pressure (PAP) of &gt;20 mmHg at rest, a pulmonary artery wedge pressure of ≤15 mmHg, and a pulmonary vascular resistance (PVR) of &gt;2 Wood units with portal hypertension. Like PAH, PoPH is underpinned by an imbalance in vasoactive substances. Therefore, current guidelines recommend PAH-specific therapies for PoPH treatment; however, descriptions of the actual treatment approaches are inconsistent. Given the small patient population, PoPH is often studied in combination with idiopathic PAH; however, recent evidence suggests important differences between PoPH and idiopathic PAH in terms of hemodynamic parameters, treatment approaches, survival, socioeconomic status, and healthcare utilization. Therefore, large, multi-center registry studies are needed to examine PoPH in isolation while obtaining statistically meaningful results. PoPH has conventionally been excluded from clinical drug trials because of concerns over hepatotoxicity. Nevertheless, newer-generation endothelin receptor antagonists have shown great promise in the treatment of PoPH, reducing PVR, PAP, and World Health Organization functional class without causing hepatotoxicity. The role of liver transplantation as a treatment option for PoPH has also been controversial; however, recent evidence shows that this procedure may be beneficial in this patient population. In the future, given the shortage of liver donors, predictors of a favorable response to liver transplantation should be determined to select the most eligible patients. Collectively, advances in these three areas could help to standardize PoPH treatment in the clinic.

Role of the Gut–Liver Axis in the Pathobiology of Cholangiopathies: Basic and Clinical Evidence

The “Gut–Liver Axis” refers to the physiological bidirectional interplay between the gut and its microbiota and the liver which, in health, occurs thanks to a condition of immune tolerance. In recent years, several studies have shown that, in case of a change in gut bacterial homeostasis or impairment of intestinal barrier functions, cholangiocytes, which are the epithelial cells lining the bile ducts, activate innate immune responses against gut-derived microorganisms or bacterial products that reach the liver via enterohepatic circulation. Intestinal dysbiosis or impaired intestinal barrier functions cause cholangiocytes to be exposed to an increasing amount of microorganisms that can reactivate inflammatory responses, thus inducing the onset of liver fibrosis. The present review focuses on the role of the gut–liver axis in the pathogenesis of cholangiopathies.

Microbiome-liver crosstalk: A multihit therapeutic target for liver disease

Liver disease has become a leading cause of death, particularly in the West, where it is attributed to more than two million deaths annually. The correlation between gut microbiota and liver disease is still not fully understood. However, it is well known that gut dysbiosis accompanied by a leaky gut causes an increase in lipopolysaccharides in circulation, which in turn evoke massive hepatic inflammation promoting liver cirrhosis. Microbial dysbiosis also leads to poor bile acid metabolism and low short-chain fatty acids, all of which exacerbate the inflammatory response of liver cells. Gut microbial homeostasis is maintained through intricate processes that ensure that commensal microbes adapt to the low oxygen potential of the gut and that they rapidly occupy all the intestinal niches, thus outcompeting any potential pathogens for available nutrients. The crosstalk between the gut microbiota and its metabolites also guarantee an intact gut barrier. These processes that protect against destabilization of gut microbes by potential entry of pathogenic bacteria are collectively called colonization resistance and are equally essential for liver health. In this review, we shall investigate how the mechanisms of colonization resistance influence the liver in health and disease and the microbial-liver crosstalk potential as therapeutic target areas.

Retracted and Republished from: "Gut Microbiota Mediates the Therapeutic Effect of Monoclonal Anti-TLR4 Antibody on Acetaminophen-Induced Acute Liver Injury in Mice"

Acetaminophen (APAP) overdose is one of the most common causes of acute liver injury (ALI) in Western countries. Many studies have shown that the gut microbiota plays an important role in liver injury. Currently, the only approved treatment for APAP-induced ALI is N-acetylcysteine; therefore, it is essential to develop new therapeutic agents and explore the underlying mechanisms. We developed a novel monoclonal anti-Toll-like receptor 4 (TLR4) antibody (ATAB) and hypothesized that it has therapeutic effects on APAP-induced ALI and that the gut microbiota may be involved in the underlying mechanism of ATAB treatment. Male C57BL/6 mice were treated with APAP and ATAB, which produced a therapeutic effect on ALI and altered the members of the gut microbiota and their metabolic pathways, such as Roseburia, Lactobacillus, Akkermansia, and the fatty acid pathway, etc. Furthermore, we verified that purified short-chain fatty acids (SCFAs) could alleviate ALI. Moreover, a separate group of mice that received feces from the ATAB group showed less severe liver injury than mice that received feces from the APAP group. ATAB therapy also improved gut barrier functions in mice and reduced the expression of the protein zonulin. Our results revealed that the gut microbiota plays an important role in the therapeutic effect of ATAB on APAP-induced ALI. IMPORTANCE In this study, we found that a monoclonal anti-Toll-like receptor 4 antibody can alleviate APAP-induced acute liver injury through changes in the gut microbiota, metabolic pathways, and gut barrier function. This work suggested that the gut microbiota can be a therapeutic target of APAP-induced acute liver injury, and we performed foundation for further research.

Modulation of duodenal and jejunal microbiota by rifaximin in mice with CCl4-induced liver fibrosis

BACKGROUND

Rifaximin is a poorly absorbed broad-spectrum antibiotic used for hepatic encephalopathy. Although increased Lactobacillaceae and decreased Bacteroidetes abundance are characteristic of hepatic encephalopathy, rifaximin does not dramatically alter the stool microbiota. As the antimicrobial effect of rifaximin increases by micellization with bile acids, we hypothesized that rifaximin alters the microbiota in the duodenum and jejunum, where the levels of bile acids are abundant.

METHODS AND RESULTS

Eight-week-old BALB/c mice were injected with carbon tetrachloride (CCl₄) intraperitoneally for 12 weeks to induce liver fibrosis. The mice were grouped into the control (n = 9), CCl₄ (n = 13), and rifaximin group in which mice were treated with rifaximin for two weeks after CCl₄ administration (n = 13). We analyzed the microbiota of the duodenum, jejunum, ileum, cecum, and stool using 16S ribosomal RNA gene analysis. The content of Lactobacillaceae, the most abundant bacterial family in the duodenum and small intestine, increased in the CCl₄ group, especially in the jejunum (median 67.0% vs 87.8%, p = 0.03). Rifaximin significantly decreased Lactobacillaceae content in the duodenum (median 79.4% vs 19.0%, p = 0.006) and jejunum (median 87.8% vs 61.3%, p = 0.03), but not in the ileum, cecum, and stool. Bacteroidetes abundance tended to decrease on CCl₄ administration and increased following rifaximin treatment in the duodenum and jejunum. S24_7, the most abundant family in Bacteroidetes, demonstrated a significant inverse correlation with Lactobacillaceae (duodenum, r = - 0.61, p < 0.001; jejunum, r = - 0.72, p < 0.001). In the ileum, cecum, and stool, the effect of rifaximin on the microbiota was minimal, with changes within the same phylum. The percentage of bacterial families, such as Lactobacillaceae and S24_7 in the duodenum and small intestine, did not correlate with that in the stool.

CONCLUSIONS

The abundance of Lactobacillaceae increased in the jejunum of mice with CCl₄-induced liver fibrosis, while rifaximin significantly reduced it in the duodenum and jejunum. Thus, rifaximin possibly exerts its effect by altering the duodenal and jejunal microbiota. Furthermore, changes in the duodenal and small intestinal microbiota were not associated with that of stool, suggesting that the analysis of stool microbiota is insufficient to evaluate upper intestinal microbiota.

Metformin alleviates liver fibrosis in mice by enriching Lactobacillus sp. MF-1 in the gut microbiota

BACKGROUND

Liver fibrosis is associated with gut dysbiosis. Metformin administration has emerged as a promising method for the treatment of organ fibrosis. We aimed to investigate whether metformin ameliorates liver fibrosis by enhancing the gut microbiota in mice with carbon tetrachloride (CCl₄)-induced liver fibrosis and the underlying mechanism.

MATERIALS AND METHODS

A liver fibrosis mouse model was established, and the therapeutic effects of metformin were observed. We administered antibiotic treatment and performed fecal microbiota transplantation (FMT), and 16S rRNA-based microbiome analysis to evaluate the effects of the gut microbiome on metformin-treated liver fibrosis. We isolated the bacterial strain preferably enriched by metformin and assessed its antifibrotic effects.

RESULTS

Metformin treatment repaired the gut integrity of the CCl₄-treated mice. It reduced the number of bacteria in colon tissues and reduced the portal vein lipopolysaccharide (LPS) levels. The FMT performed on the metformin-treated CCl₄ mice alleviated their liver fibrosis and reduced their portal vein LPS levels. The markedly changed gut microbiota was screened out from the feces and named Lactobacillus sp. MF-1 (L. sp. MF-1). In the CCl₄-treated mice, daily gavage of L. sp. MF-1 maintained gut integrity, inhibited bacterial translocation, and reduced liver fibrosis. Mechanistically, metformin or L. sp. MF-1 inhibited the apoptosis of intestinal epithelial cells and restored CD3⁺ intestinal intraepithelial lymphocytes in the ileum and CD4⁺Foxp3⁺ lamina propria lymphocytes in the colon.

CONCLUSIONS

Metformin and its enriched L. sp. MF-1 can reinforce the intestinal barrier to alleviate liver fibrosis by restoring immune function.

Retrorsine Cooperates with Gut Microbiota to Promote Hepatic Sinusoidal Obstruction Syndrome by Disrupting the Gut Barrier

BACKGROUND AND AIMS

Hepatic sinusoidal obstruction syndrome (HSOS) is a life-threatening syndrome, and a cause is exposure to pyrrolizidine alkaloid (PA)-containing products. It is well-established that retrorsine (RTS), a representative Pas, insults hepatic sinusoidal endothelial cells and ensues congestion of hepatic sinusoids. However, little known about the impact of Pas on gut microbiota and intestinal barrier and inflammation in HSOS.

METHODS

Mice were gavaged with or without nonabsorbable antibiotics (ABX), followed by a single dose of RTS. The gut microbiota was examined by 16S rDNA sequencing.

RESULTS

ABX pretreatment significantly reversed RTS-induced liver damage. RTS altered gut microbiota composition, increasing Gram-negative bacteria and resulting in a sharp elevation of circulating lipopolysaccharides (LPS) in HSOS mice. Gut decontamination with ABX alleviated RTS-induced intestine inflammation, protected against disruption of the intestinal epithelial barrier and gut vascular barrier (GVB), and suppressed hepatic LPS-NF-κB pathway activation in RTS-induced HSOS. Importantly, the LPS level was positively correlated with MELD score in patients with HSOS. Elevated LPS in patients with HSOS confirmed that Gram-negative bacteria were involved in the pathogenesis of HSOS.

CONCLUSIONS

RTS, a PA, cooperated with gut dysbiosis to cause intestinal inflammation and gut barrier compromise that increased transport of gut-derived LPS into the liver through the portal vein, which contributed to the pathology of HSOS. Modulating the gut microbiota, protecting the intestinal barrier, and suppressing intestinal inflammation with prebiotics or antibiotics might be a useful pharmacologic intervention in HSOS.

Brain-gut-liver axis: Chronic psychological stress promotes liver injury and fibrosis via gut in rats

Background

The effect of chronic psychological stress on hepatitis and liver fibrosis is concerned. However, its mechanism remains unclear. We investigated the effect and mechanism of chronic psychological stress in promoting liver injury and fibrosis through gut.

Methods

Sixty male SD rats were randomly assigned to 6 groups. Rat models of chronic psychological stress (4 weeks) and liver fibrosis (8 weeks) were established. The diversity of gut microbiota in intestinal feces, permeability of intestinal mucosa, pathologies of intestinal and liver tissues, collagen fibers, protein expressions of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), nuclear factor kappa β (NF-κβ), tumor necrosis factor α (TNF-α) and interleukin 1 (IL-1) in liver tissue, liver function and coagulation function in blood and lipopolysaccharide (LPS) in portal vein blood were detected and analyzed.

Results

The diversities and abundances of gut microbiota were significant differences in rats among each group. The pathological lesions of intestinal and liver tissues, decreased expression of occludin protein in intestinal mucosa, deposition of collagen fibers and increased protein expression of TLR4, MyD88, NF-κβ, TNF-α and IL-1 in liver tissue, increased LPS level in portal vein blood, and abnormalities of liver function and coagulation function, were observed in rats exposed to chronic psychological stress or liver fibrosis. There were significant differences with normal rats. When the dual intervention factors of chronic psychological stress and liver fibrosis were superimposed, the above indicators were further aggravated.

Conclusion

Chronic psychological stress promotes liver injury and fibrosis, depending on changes in the diversity of gut microbiota and increased intestinal permeability caused by psychological stress, LPS that enters liver and acts on TLR4, and active LPS-TLR4 pathway depend on MyD88. It demonstrates the possibility of existence of brain-gut-liver axis.

Model of Liver Fibrosis Induction by Thioacetamide in Rats for Regenerative Therapy Studies

Hepatic fibrosis is caused by chronic injury due to toxic, infectious, or metabolic causes, and it may progress to cirrhosis and hepatocellular carcinoma. There is currently no antifibrotic therapy authorized for human use; however, there are promising studies using cell therapies. There are also no animal models that exactly reproduce human liver fibrosis that can be used to better understand the mechanisms of its regression and identify new targets for treatment and therapeutic approaches. On the other hand, mesenchymal stem cells (MSC) have experimentally demonstrated fibrosis regression effects, but it is necessary to have an animal model of advanced liver fibrosis to evaluate the effect of these cells. The aim of this work was to establish a protocol for the induction of advanced liver fibrosis in rats using thioacetamide (TAA), which will allow us to perform trials using MSC as a possible therapy for fibrosis regression. For this purpose, we selected 24 female rats and grouped them into three experimental groups: the control group (G-I) without treatment and groups II (G-II) and III (G-III) that received TAA by intraperitoneal injection for 24 weeks. Then, 1 × 106/kg adipose mesenchymal stem cells (ASCs) were infused intravenously. Groups G-I and G-II were sacrificed 7 days after the last dose of ASC, and G-III was sacrificed 8 weeks after the last ASC infusion, all with xylazine/ketamine (40 mg/kg). The protocol used in this work established a model of advanced hepatic fibrosis as corroborated by METAVIR tests of the histological lesions; by the high levels of the markers α-SMA, CD68, and collagen type I; by functional alterations due to elevated markers of the hepatic lesions; and by alterations of the leukocytes, lymphocytes, and platelets. Finally, transplanted cells in the fibrous liver were detected. We conclude that TAA applied using the protocol introduced in this study induces a good model of advanced liver fibrosis in rats.

Lipopolysaccharide Inhibits Autophagy and Promotes Inflammatory Responses via p38 MAPK-Induced Proteasomal Degradation of Atg13 in Hepatic Stellate Cells

Background

Inflammation plays a critical role in the progression of acute-on-chronic liver failure (ACLF). Atg13 is a vital regulatory component of the ULK1 complex, which plays an essential role in the initiation of autophagy. Previously, hepatic stellate cells (HSCs) were considered to be noninflammatory cells that contribute only to hepatic fibrosis. Recently, it has been found that HSCs can secrete inflammatory cytokines and participate in hepatic inflammation. Autophagy and proteasome-mediated degradation constitute two major means of protein turnover in cells. Autophagy has been shown to regulate inflammation, but it is unclear whether ubiquitin (Ub)-proteasome system (UPS) is involved in inflammatory responses in HSCs during ACLF.

Methods

Clinical data were collected from ACLF patients, and surgically resected paraffin-embedded human ACLF liver tissue specimens were collected. The expression of Atg13 was assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Secretion of IL-1β was assessed by ELISA. Atg13 was knocked down by siRNA in LX2 cells. Coimmunoprecipitation assay was used to detect protein binding and polyubiquitination of Atg13. In vitro tests with LX2 cells were performed to explore the effects and regulation of p38 MAPK, Atg13, UPS, autophagy, and inflammation.

Results

Serum lipopolysaccharide (LPS) was positively associated with disease severity in ACLF patients, and p38 MAPK was overexpressed in ACLF liver tissue. We evaluated the role of Atg13 in HSC inflammation and explored the possible underlying mechanisms. Inflammatory factors were upregulated via activation of p38 MAPK and inhibition of autophagy in LX-2 cells. Expression of Atg13 was decreased in LPS-incubated LX2 cells. Atg13 knockdown markedly inhibited autophagy and promoted LPS-induced inflammation in LX2 cells. Our in vitro experiments also showed that LPS induced depletion of Atg13 via UPS, and this process was dependent on p38 MAPK.

Conclusions

LPS induces proteasomal degradation of Atg13 via p38 MAPK, thereby participating in the aggravation of LPS-induced autophagy inhibition and inflammatory responses in LX2 cells. Atg13 serves as a mediator between autophagy and proteasome. Modulation of Atg13 or proteasome activity might be a novel strategy for treating HSC inflammation.

Antibiotics enhancing drug-induced liver injury assessed for causality using Roussel Uclaf Causality Assessment Method: Emerging role of gut microbiota dysbiosis

Drug-induced liver injury (DILI) is a disease that remains difficult to predict and prevent from a clinical perspective, as its occurrence is hard to fully explain by the traditional mechanisms. In recent years, the risk of the DILI for microbiota dysbiosis has been recognized as a multifactorial process. Amoxicillin-clavulanate is the most commonly implicated drug in DILI worldwide with high causality gradings based on the use of RUCAM in different populations. Antibiotics directly affect the structure and diversity of gut microbiota (GM) and changes in metabolites. The depletion of probiotics after antibiotics interference can reduce the efficacy of hepatoprotective agents, also manifesting as liver injury. Follow-up with liver function examination is essential during the administration of drugs that affect intestinal microorganisms and their metabolic activities, such as antibiotics, especially in patients on a high-fat diet. In the meantime, altering the GM to reconstruct the hepatotoxicity of drugs by exhausting harmful bacteria and supplementing with probiotics/prebiotics are potential therapeutic approaches. This review will provide an overview of the current evidence between gut microbiota and DILI events, and discuss the potential mechanisms of gut microbiota-mediated drug interactions. Finally, this review also provides insights into the "double-edged sword" effect of antibiotics treatment against DILI and the potential prevention and therapeutic strategies.

Bile Salt Hydrolase-Competent Probiotics in the Management of IBD: Unlocking the "Bile Acid Code"

Bile acid (BA) species and the gut microbiota (GM) contribute to intestinal mucosa homeostasis. BAs shape the GM and, conversely, intestinal bacteria with bile salt hydrolase (BSH) activity modulate the BA pool composition. The mutual interaction between BAs and intestinal microorganisms also influences mucosal barrier integrity, which is important for inflammatory bowel disease (IBD) pathogenesis, prevention and therapy. High levels of secondary BAs are detrimental for the intestinal barrier and increase the intestinal inflammatory response and dysbiosis. Additionally, a lack of BSH-active bacteria plays a role in intestinal inflammation and BA dysmetabolism. Thus, BSH-competent bacteria in probiotic formulations are being actively studied in IBD. At the same time, studies exploring the modulation of the master regulator of BA homeostasis, the Farnesoid X Receptor (FXR), in intestinal inflammation and how this impacts the GM are gaining significant momentum. Overall, the choice of probiotic supplementation should be a peculiar issue of personalized medicine, considering not only the disease but also the specific BA and metabolic signatures of a given patient.

Retrospective analysis of liver lobe torsion in pet rabbits: 40 cases (2016-2021)

BACKGROUND

Liver lobe torsion (LLT) in rabbits can be under-recognised and potentially fatal. The clinical features of cases presented to an exotic animal veterinary service in Australia were retrospectively reviewed.

METHOD

Medical records of confirmed rabbit LLT cases between 2016 and 2021 were reviewed for signalment, clinical signs and findings, diagnostic imaging results, management strategies and outcomes. Variables of interest were analysed for statistical association with outcome.

RESULTS

A total of 40 rabbits were included. The mean presenting age was 56.2 months (SD 30.5). Neutered males (23/40, 57.5%) were over-represented. Common clinical signs and findings included reduced appetite (40/40, 100%), lethargy (32/40, 80.0%), reduced faecal production (16/40, 40.0%), a doughy distended stomach (20/40, 50.0%), pale mucous membranes (19/40, 47.5%) and hypothermia (17/40, 42.5%). Anaemia and elevated plasma alanine aminotransferase and blood urea nitrogen were common clinicopathologic findings. Computed tomography (CT) was performed in 34 of 40 rabbits, confirming the presence and position of LLT (34/34, 100%), stenosis of the caudal vena cava or portal system (28/34, 82.4%) and increased free peritoneal fluid (29/34, 85.3%). Fifteen (15/40, 37.5%) rabbits were medically managed, and surgical intervention was performed in 23 of 40 (57.5%) rabbits. Overall, 30 of 40 (75.0%) rabbits survived. Surgical intervention did not confer a significant difference in outcome compared to medical management (odds ratio 0.77, 95% confidence interval 0.15-4.10, p = 0.761).

CONCLUSION

CT can be an invaluable diagnostic modality for rabbit LLT. Favourable outcomes can be achieved in selected cases with medical management alone.

Tet2 deficiency drives liver microbiome dysbiosis triggering Tc1 cell autoimmune hepatitis

The triggers that drive interferon-γ (IFNγ)-producing CD8 T cell (Tc1 cell)-mediated autoimmune hepatitis (AIH) remain obscure. Here, we show that lack of hematopoietic Tet methylcytosine dioxygenase 2 (Tet2), an epigenetic regulator associated with autoimmunity, results in the development of microbiota-dependent AIH-like pathology, accompanied by hepatic enrichment of aryl hydrocarbon receptor (AhR) ligand-producing pathobionts and rampant Tc1 cell immunity. We report that AIH-like disease development is dependent on both IFNγ and AhR signaling, as blocking either reverts ongoing AIH-like pathology. Illustrating the critical role of AhR-ligand-producing pathobionts in this condition, hepatic translocation of the AhR ligand indole-3-aldehyde (I3A)-releasing Lactobacillus reuteri is sufficient to trigger AIH-like pathology. Finally, we demonstrate that I3A is required for L. reuteri-induced Tc1 cell differentiation in vitro and AIH-like pathology in vivo, both of which are restrained by Tet2 within CD8 T cells. This AIH-disease model may contribute to the development of therapeutics to alleviate AIH.

Hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) is a pulmonary vascular complication of liver disease, which adversely affects prognosis. The disease is characterised by intrapulmonary vascular dilatations and shunts, resulting in impaired gas exchange. A complex interaction between the liver, the gut and the lungs, predominately impacting pulmonary endothelial cells, immune cells and respiratory epithelial cells, is responsible for the development of typical pulmonary alterations seen in HPS. Liver transplantation is the only therapeutic option and generally reverses HPS. Since the implementation of the model for end-stage liver disease (MELD) standard exception policy, outcomes in patients with HPS have been significantly better than they were in the pre-MELD era. This review summarises current knowledge and highlights what’s new regarding the diagnosis and management of HPS, and our understanding of pathogenesis based on experimental models and translational studies.

Role of bile acids and their receptors in gastrointestinal and hepatic pathophysiology

Bile acids (BAs) can regulate their own metabolism and transport as well as other key aspects of metabolic homeostasis via dedicated (nuclear and G protein-coupled) receptors. Disrupted BA transport and homeostasis results in the development of cholestatic disorders and contributes to a wide range of liver diseases, including nonalcoholic fatty liver disease and hepatocellular and cholangiocellular carcinoma. Furthermore, impaired BA homeostasis can also affect the intestine, contributing to the pathogenesis of irritable bowel syndrome, inflammatory bowel disease, and colorectal and oesophageal cancer. Here, we provide a summary of the role of BAs and their disrupted homeostasis in the development of gastrointestinal and hepatic disorders and present novel insights on how targeting BA pathways might contribute to novel treatment strategies for these disorders.

Cigarette smoking and liver diseases

Cigarette smoking is a preventable risk factor for premature morbidity and mortality. A history of smoking is observed in approximately 40% of patients with liver disease, while a growing number of studies are investigating the potential impact of smoking in chronic liver diseases. This review discusses the effects of smoking on liver diseases, at multiple levels, with a focus on its potential causal role. Clinical evidence indicates that cigarette smoking negatively impacts the incidence and severity of fatty liver disease, fibrosis progression, hepatocellular carcinoma development, and the outcomes of patients with advanced liver disease. The underlying mechanisms are complex and involve different pathophysiological pathways including oxidative stress and oncogenic signals. Importantly, smoking promotes cardiovascular disease and extrahepatic cancers in patients with steatohepatitis and in transplant recipients. We discuss how promoting smoking cessation could improve the rates of treatment response (in clinical trials) and fibrosis regression, while reducing the risk of hepatocellular carcinoma and improving liver transplant outcomes. Finally, we discuss current challenges such as the referral of smokers to specialised units for smoking cessation.

Gut Microbiota Mediates the Therapeutic Effect of Monoclonal Anti-TLR4 Antibody on Acetaminophen-Induced Acute Liver Injury in Mice

Acetaminophen (APAP) overdose is one of the most common causes of acute liver injury (ALI) in Western countries. Many studies show that the gut microbiota plays an important role in liver injury. Currently, the only approved treatment for APAP-induced ALI is N-acetylcysteine; therefore, it is essential to develop new therapeutic agents and explore the underlying mechanisms. We developed a novel monoclonal anti-Toll-like receptor 4 (TLR4) antibody (ATAB) and hypothesized that it has therapeutic effects on APAP-induced ALI and that gut microbiota may be involved in the underlying mechanism of ATAB treatment. Male C57BL/6 mice were treated with APAP and ATAB, which produced a therapeutic effect on ALI and altered the gut microbiota and their metabolic pathway, such as Roseburia, Lactobacillus, Akkermansia, and the fatty acid pathway, etc. Furthermore, we verified that purified short-chain fatty acids (SCFAs) could alleviate ALI. Moreover, a separate group of mice that received feces from the ATAB group showed less severe liver injury compared with the mice receiving feces from the APAP group. ATAB therapy also improved the gut barrier functions in mice and reduced the expression of protein zonulin. Our results revealed that gut microbiota plays an important role in the therapeutic effect of ATAB on APAP-induced ALI. IMPORTANCE In this study, we found the monoclonal anti-Toll-like receptor 4 antibody can alleviate APAP-induced acute liver injury through the change of the gut microbiota, metabolic pathways, and gut barrier function. This work suggested the gut microbiota can be the therapeutic target of the APAP-induced acute liver injury, and we performed the fundamental research for further research.

Vaccination With Leptospira interrogans PF07598 Gene Family-Encoded Virulence Modifying Proteins Protects Mice From Severe Leptospirosis and Reduces Bacterial Load in the Liver and Kidney

The molecular and cellular pathogenesis of leptospirosis remains poorly understood. Based on comparative bacterial genomics data, we recently identified the hypothetical PF07598 gene family as encoding secreted exotoxins (VM proteins) that mediate cytotoxicity in vitro. To address whether VM proteins mediate in vivo leptospirosis pathogenesis, we tested the hypothesis that VM protein immunization of mice would protect against lethal challenge infection and reduce bacterial load in key target organs. C3H/HeJ mice were immunized with recombinant E. coli-produced, endotoxin-free, leptospiral VM proteins (derived from L. interrogans serovar Lai) in combination with the human-compatible adjuvant, glucopyranoside lipid A/squalene oil-in-water. Mice receiving full length recombinant VM proteins were protected from lethal challenge infection by L. interrogans serovar Canicola and had a 3-4 log₁₀ reduction in bacterial load in the liver and kidney. These experiments show that immunization with recombinant VM proteins prevents leptospirosis clinical pathogenesis and leads to markedly reduced key target organ infection in this animal model. These data support the role of leptospiral VM proteins as virulence factors and suggest the possibility that a VM protein-based, serovar-independent, pan-leptospirosis vaccine may be feasible.

Preventing Bacterial Translocation in Patients with Leaky Gut Syndrome: Nutrition and Pharmacological Treatment Options

Leaky gut syndrome is a medical condition characterized by intestinal hyperpermeability. Since the intestinal barrier is one of the essential components maintaining homeostasis along the gastrointestinal tract, loss of its integrity due to changes in bacterial composition, decreased expression levels of tight junction proteins, and increased concentration of pro-inflammatory cytokines may lead to intestinal hyperpermeability followed by the development of gastrointestinal and non-gastrointestinal diseases. Translocation of microorganisms and their toxic metabolites beyond the gastrointestinal tract is one of the fallouts of the leaky gut syndrome. The presence of intestinal bacteria in sterile tissues and distant organs may cause damage due to chronic inflammation and progression of disorders, including inflammatory bowel diseases, liver cirrhosis, and acute pancreatitis. Currently, there are no medical guidelines for the treatment or prevention of bacterial translocation in patients with the leaky gut syndrome; however, several studies suggest that dietary intervention can improve barrier function and restrict bacteria invasion. This review contains current literature data concerning the influence of diet, dietary supplements, probiotics, and drugs on intestinal permeability and bacterial translocation.