Targeting the gut-liver-immune axis to treat cirrhosis

Gut Microbiota and Cytokine Profile in Cirrhosis

Background and Aims

Gut dysbiosis and abnormal cytokine profiles are common in cirrhosis. This study aimed to evaluate the correlations between them.

Methods

In the blood plasma of cirrhosis patients and controls, 27 cytokines were examined using a multiplex assay. The plasma levels of nitrites (stable metabolites of the endothelial dysfunction biomarker nitric oxide) and lipopolysaccharide (LPS) were examined. The fecal microbiota was assessed by 16S rRNA gene sequencing.

Results

Levels of IL-1b, IL-2, IL-6, IL-13, IP-10, IFN-g, TNF-a, LPS, and nitrites were higher in cirrhosis patients than in controls, while levels of IL-4, IL-7, and PDGF-BB were lower. The LPS level was directly correlated with the levels of IL-1b, IL1-Ra, IL-9, IL-17, PDGF-BB, IL-6, TNF-a, and nitrites. The nitrite level was significantly directly correlated with the levels of TNF-a, GM-CSF, IL-17, and IL-12, and inversely correlated with the IL-7 level. TNF-a levels were directly correlated with ascites severity and the abundance of Negativicutes, Enterobacteriaceae, Veillonellaceae, and Klebsiella, while inversely correlated with the abundance of Firmicutes, Clostridia, and Subdoligranulum. IFN-g levels were directly correlated with the abundance of Bacteroidaceae, Lactobacillaceae, Bacteroides, and Megasphaera, and inversely correlated with the abundance of Verrucomicrobiota, Akkermansiaceae, Coriobacteriaceae, Akkermansia, Collinsella, and Gemella. IL-1b levels were directly correlated with the abundance of Comamonadaceae and Enterobacteriaceae and inversely correlated with the abundance of Marinifilaceae and Dialister. IL-6 levels were directly correlated with the abundance of Enterobacteriaceae, hepatic encephalopathy, and ascites severity, and inversely correlated with the abundance of Peptostreptococcaceae, Streptococcaceae, and Streptococcus.

Conclusions

The abundance of harmful gut microbiota taxa and endotoxinemia directly correlates with the levels of proinflammatory cytokines.

Efficacy of probiotics on improvement of health outcomes in cirrhotic liver disease patients: A systematic review and meta-analysis of randomised controlled trials

Liver cirrhosis is a chronic condition of the liver and is the 14th most common cause of death around the world; yet it remains an incurable disease. Probiotics have gained significant popularity as a potential treatment option for liver cirrhosis.

METHODS

A systematic review and meta-analysis was conducted to assess the effects of probiotics on liver cirrhosis. PubMed, Scopus, Cochrane Central Register for Controlled Trials (CENTRAL) and ProQuest Dissertation and Thesis were searched from 2000 to January 2024 for studies that evaluated the effects of probiotics on a variety of outcomes of liver disease.

RESULTS

A total of 22 randomised controlled trial studies were included in the meta-analysis. Probiotics significantly decreased Gamma-glutamyl transferase (effect size: 0.307, p = 0.024, 95% CI [-0.572, -0.040]) and Aspartate aminotransferase (p = 0.013, 95% CI [-17.927, -2.128]). Significant reduction in serum ammonia levels (effect size = -1.093, p = 0.000, 95% CI [-1.764, -0.423]) and endotoxin levels (effect size = -0.961, p = 0.000, 95% CI [-1.537, -0.385]) were also found.

SUMMARY

Overall probiotics could be recommended as a potential adjunct therapy for patients with cirrhosis, as they appear to have some benefit in improving liver function, and are well tolerated with minimal adverse effects. More comprehensive research with larger sample sizes is recommended to understand more about the widespread effects of probiotic use.

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.

The Value of Neutrophil-to-Lymphocyte Ratio in Predicting Mortality After Transjugular Intrahepatic Portosystemic Shunt Placement

Background and Aims

The objective of this study was to investigate the effect of neutrophil-to-lymphocyte ratio (NLR) on the survival of cirrhotic patients with esophagogastric variceal bleeding (EGVB) treated with transjugular intrahepatic portosystemic shunt (TIPS).

Methods

A total of 293 patients treated with TIPS were included. The receiver operator characteristic curve (ROC) was used to calculate the optimal cut-off values of parameters such as NLR. The Kaplan-Meier curve and Cox proportional risk model were used to evaluate the effects of NLR and other variables on 2-year all-cause mortality.

Results

The area under the ROC for NLR was 0.634, with an optimal cutoff value of 4.9. Two-year mortality rates for patients with high (≥4.9) and low (<4.9) NLR were 22.1% and 9.3%, respectively (Log rank test: P = 0.002). After correcting for confounders, multivariate analysis demonstrated that NLR ≥ 4.9 (HR = 2.741, 95% CI 1.467-5.121, P = 0.002), age ≥ 63 (HR = 3.403, 95% CI 1.835-6.310, P < 0.001), and gender (male) (HR = 2.842, 95% CI 1.366-5.912, P = 0.001) were independent risk factors for the mortality outcome. Considering the stratification of early and selective TIPS treatment, high NLR still significantly increased the risk of mortality for patients (Log rank test: P = 0.007, HR = 2.317, 95% CI 1.232-4.356).

Conclusion

NLR can help to predict survival in EGVB patients after TIPS, and the type of TIPS should also be considered in practical applications.

Microbial-derived Urolithin A Targets GLS1 to Inhibit Glutaminolysis and Attenuate Cirrhotic Portal Hypertension

BACKGROUND & AIMS

Cirrhotic portal hypertension (CPH) is the leading cause of mortality in patients with cirrhosis. Over 50% of patients with CPH treated with current clinical pharmacotherapy still present variceal bleeding or sometimes death owing to insufficient reduction in portal pressure. Elevated intrahepatic vascular resistance (IHVR) plays a fundamental role in increasing portal pressure. Because of its potent effect in reducing portal pressure and maintaining normal portal inflow to preserve liver function, lowering the IHVR is acknowledged as an optimal anti-CPH strategy but without clinical drugs. We aimed to investigate the protective effect of microbial-derived Urolithin A (UroA) in IHVR and CPH.

METHODS

Carbon tetrachloride or bile duct ligation surgery was administered to mice to induce liver fibrosis and CPH. 16S rRNA gene sequencing was used for microbial analysis. Transcriptomics and metabolomics analyses were employed to study the host and cell responses.

RESULTS

UroA was remarkably deficient in patients with CPH and was negatively correlated with disease severity. UroA deficiency was also confirmed in CPH mice and was associated with a reduced abundance of UroA-producing bacterial strain (Lactobacillus murinus, L. murinus). Glutaminolysis of hepatic stellate cells (HSCs) was identified as a previously unrecognized target of UroA. UroA inhibited the activity of glutaminase1 to suppress glutaminolysis, which counteracted fibrogenesis and contraction of HSCs and ameliorated CPH by relieving IHVR. Supplementation with UroA or L. murinus effectively ameliorated CPH in mice.

CONCLUSIONS

We for the first time identify the deficiency of gut microbial metabolite UroA as an important cause of CPH. We demonstrate that UroA exerts an excellent anti-CPH effect by suppressing HSC glutaminolysis to lower the IHVR, which highlighted its great potential as a novel therapeutic agent for CPH.

Gut microbial metabolites in MASLD: Implications of mitochondrial dysfunction in the pathogenesis and treatment

With an increasing prevalence, metabolic dysfunction-associated steatotic liver disease (MASLD) has become a major global health problem. MASLD is well-known as a multifactorial disease. Mitochondrial dysfunction and alterations in the gut bacteria are 2 vital events in MASLD. Recent studies have highlighted the cross-talk between microbiota and mitochondria, and mitochondria are recognized as pivotal targets of the gut microbiota to modulate the host's physiological state. Mitochondrial dysfunction plays a vital role in MASLD and is associated with multiple pathological changes, including hepatocyte steatosis, oxidative stress, inflammation, and fibrosis. Metabolites are crucial mediators of the gut microbiota that influence extraintestinal organs. Additionally, regulation of the composition of gut bacteria may serve as a promising therapeutic strategy for MASLD. This study reviewed the potential roles of several common metabolites in MASLD, emphasizing their impact on mitochondrial function. Finally, we discuss the current treatments for MASLD, including probiotics, prebiotics, antibiotics, and fecal microbiota transplantation. These methods concentrate on restoring the gut microbiota to promote host health.

FXR-FGF19 signaling in the gut-liver axis is dysregulated in patients with cirrhosis and correlates with impaired intestinal defence

BACKGROUND AND AIMS

Experimental studies linked dysfunctional Farnesoid X receptor (FXR)-fibroblast growth factor 19 (FGF19) signaling to liver disease. This study investigated key intersections of the FXR-FGF19 pathway along the gut-liver axis and their link to disease severity in patients with cirrhosis.

METHODS

Patients with cirrhosis undergoing hepatic venous pressure gradient measurement (cohort-I n = 107, including n = 53 with concomitant liver biopsy; n = 5 healthy controls) or colonoscopy with ileum biopsy (cohort-II n = 37; n = 6 controls) were included. Hepatic and intestinal gene expression reflecting FXR activation and intestinal barrier integrity was assessed. Systemic bile acid (BA) and FGF19 levels were measured.

RESULTS

Systemic BA and FGF19 levels correlated significantly (r = 0.461; p < 0.001) and increased with cirrhosis severity. Hepatic SHP expression decreased in patients with cirrhosis (vs. controls; p < 0.001), indicating reduced FXR activation in the liver. Systemic FGF19 (r = -0.512, p < 0.001) and BA (r = -0.487, p < 0.001) levels correlated negatively with hepatic CYP7A1, but not SHP or CYP8B1 expression, suggesting impaired feedback signaling in the liver. In the ileum, expression of FXR, SHP and FGF19 decreased in patients with cirrhosis, and interestingly, intestinal FGF19 expression was not linked to systemic FGF19 levels. Intestinal zonula occludens-1, occludin, and alpha-5-defensin expression in the ileum correlated with SHP and decreased in patients with decompensated cirrhosis as compared to controls.

CONCLUSIONS

FXR-FGF19 signaling is dysregulated at essential molecular intersections along the gut-liver axis in patients with cirrhosis. Decreased FXR activation in the ileum mucosa was linked to reduced expression of intestinal barrier proteins. These human data call for further mechanistic research on interventions targeting the FXR-FGF19 pathway in patients with cirrhosis.

CLINICAL TRIAL NUMBER

NCT03267615.

Targeted delivery strategies: The interactions and applications of nanoparticles in liver diseases

In recent years, nanoparticles have been broadly utilized in various drugs delivery formulations. Nanodelivery systems have shown promise in solving problems associated with the distribution of hydrophobic drugs and have promoted the accumulation of nanomedicines in the circulation or in organs. However, the injection dose of nanoparticles (NPs) is much greater than that needed by diseased tissues or organs. In other words, most of the NPs are localized off-target and do not reach the desired tissue or organs. With the rapid development of biodegradable and biosafety nanomaterials, the nanovectors represent assurance of safety. However, the off-target effects also induce concerns about the application of NPs, especially in the delivery of gene editing tools. Therefore, a complete understanding of the biological responses to NPs in the body will clearly guide the design of targeted delivery of NPs. The different properties of various nanodelivery systems may induce diverse interactions between carriers and organs. In this review, we describe the relationship between the liver, the most influenced organ of systemic administration of NPs, and targeted delivery nanoplatforms. Various transport vehicles have adopted multiple delivery strategies for the targeted delivery to the cells in the homeostasis liver and in diseased liver. Additionally, nanodelivery systems provide a novel strategy for treating incurable diseases. The appearance of a targeted delivery has profoundly improved the application of NPs to liver diseases.

Fecal microbiota transplantation in the treatment of hepatic encephalopathy: A perspective

Due to its complex pathogenesis, treatment of hepatic encephalopathy (HE) continues to be a therapeutic challenge. Of late, gut microbiome has garnered much attention for its role in the pathogenesis of various gastrointestinal and liver diseases and its potential therapeutic use. New evidence suggests that gut microbiota plays a significant role in cerebral homeostasis. Alteration in the gut microbiota has been documented in patients with HE in a number of clinical and experimental studies. Research on gut dysbiosis in patients with HE has opened newer therapeutic avenues in the form of probiotics, prebiotics and the latest fecal microbiota transplantation (FMT). Recent studies have shown that FMT is safe and could be effective in improving outcomes in advanced liver disease patients presenting with HE. However, questions over the appropriate dose, duration and route of administration for best treatment outcome remains unsettled.

Bacterial profile, drug resistance pattern, clinical and laboratory predictors of ascites infection in cirrhosis patients

Ascites is a pathological collection of free fluid in the peritoneal cavity, which is a common complication in patients with cirrhosis, an advanced liver disease. Bacterial infection increases the mortality rate of hospitalized patients with cirrhosis, irrespective of the severity of the liver disease. Around 60% of patients with compensated cirrhosis developed ascites within 10 years during the course of their disease. The in-hospital mortality rate due to spontaneous bacterial peritonitis (SBP) could exceed 90%, but with early diagnosis and prompt antibiotic therapy, this rate has been shown to decrease to 20%. Here, we enrolled adult (age ≥ 18) patients with liver disease with evidence of cirrhosis who developed ascites and assessed the presence of spontaneous ascites fluid infection (SAFI) in these patients. Of the total 218 patients, 22.9% (50/218) develop ascites infection. The liver organ function tests like alanine aminotransferase, aspartate aminotransferase, total bilirubin, and direct bilirubin were found to be significantly (P < 0.05) higher in patients with ascites fluid infection compared to patients with non-ascites fluid infection. Of the gram-negative bacteria, K. pneumonia and E. coli were isolated and found to be 100% resistant to amoxicillin and clavulanate. From the gram-positive bacterial isolates, S. aureus was only resistant to penicillin, whereas Str. viridans was resistant to ceftriaxone, cefotaxime, cefepime, and penicillin. On the other hand, clinical features such as a history of jaundice, low arterial blood pressure, and ultrasound results such as a shrunken liver and enlarged spleen were also independent predictors of spontaneous bacterial peritonitis. In conclusion, given the high probability of death following SAFI, early detection, and treatment, as well as knowledge of the microbial agent, resistance profile, and predictive markers in various contexts, are essential for the timely diagnosis and management of SAFI in these patients.

Ascitic microbiota alteration is associated with portal vein tumor thrombosis occurrence and prognosis in hepatocellular carcinoma

Portal vein tumor thrombosis (PVTT) frequently leads to malignant ascites (MA) in individuals with hepatocellular carcinoma (HCC), remaining a bottleneck in the treatment. This study aimed to explore the differences in microbes in paired groups and provide novel insights into PVTT and MA-related treatments. Formalin-fixed paraffin embedding ascite samples were collected from MA secondary to HCC and benign ascites (BA) secondary to liver cirrhosis (LC). Ascitic microbiota profiles were determined in the HCC and LC groups by 16S rRNA sequencing. Prognostic risk factors were screened using survival analysis. The correlation between the significantly different microbial signatures in the groups with PVTT (WVT) and non-PVTT (NVT) and clinical characteristics was explored. The expression of different immune cells was determined by labeling four markers in the MA tissue chips using multiplex immunohistochemistry. A total of 240 patients (196 with HCC with MA and 44 with LC with BA) were included in this study. Microbial profiles differed between the HCC and LC groups. PVTT and Barcelona Clinic Liver Cancer stage were shown to be prognostic risk factors. Significant differences in the alpha and beta diversities were observed between the WVT and NVT groups. Gammaproteobacteria and Acinetobacter were the most abundant in the HCC MA. Differences in microbial signatures between the WVT and NVT groups were correlated with the level of C-reactive protein and apolipoprotein A1. This study revealed the microbial differences in the tumor microenvironment of MA secondary to HCC and BA secondary to LC.IMPORTANCEFirst, we explored the alteration of the ascites ecosystem through the microbiota in patients with hepatocellular carcinoma (HCC) and liver cirrhosis. Second, this is the first clinical study to investigate the differences between patients with HCC with and without portal vein tumor thrombosis via 16S rRNA sequencing. These results revealed a decreased microbial diversity and metabolic dysregulation in individuals with HCC and portal vein tumor thrombosis. Gammaproteobacteria and Acinetobacter were the most abundant in the HCC malignant ascitic fluid. Our study provides a new perspective on treating malignant ascites secondary to HCC.

HIV-Negative Case of Talaromyces marneffei Pulmonary Infection with Liver Cirrhosis in China: A Case Report and Literature Review

Background

Talaromyces marneffei (TM) is the third most prevalent opportunistic infection in HIV-positive patients after tuberculosis and cryptococcosis. However, such infection of non-HIV individuals has rarely been reported.

Case Presentation

We describe a very rare case of a 52-year-old male who presented with a single space-occupying lesion on the right lung and was eventually diagnosed with pulmonary TM infection. The patient was HIV-negative and had liver cirrhosis with portal vein thrombosis. Lung tissue next-generation sequencing (NGS) revealed TM infection. We successfully treated the patient with voriconazole for 8 weeks and observed lesion absorption via subsequent CT. The patient consumed wild bamboo rats two months before admission. Mutations related to congenital immune deficiency were not detected by whole-exome sequencing.

Conclusion

Early and timely diagnosis is critical for improving patient prognosis. NGS plays a vital role in the diagnosis of pulmonary TM infection in patients. To our knowledge, this is the first published case of pulmonary TM infection in an HIV-negative patient with liver cirrhosis.

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.

The challenges and potential of microRNA-based therapy for patients with liver failure syndromes and hepatocellular carcinoma

INTRODUCTION

Morbidity and mortality from liver disease continues to rise worldwide. There are currently limited curative treatments for patients with liver failure syndromes, encompassing acute liver failure and decompensated cirrhosis states, outside of transplantation. Whilst there have been improvements in therapeutic options for patients with hepatocellular carcinoma (HCC), there remain challenges necessitating novel therapeutic agents. microRNA have long been seen as potential therapeutic targets but there has been limited clinical translation.

AREAS COVERED

We will discuss the limitations of conventional non-transplant management of patients with liver failure syndromes and HCC. We will provide an overview of microRNA and the challenges in developing and delivering microRNA-based therapeutic agents. We will finally provide an overview of microRNA-based therapeutic agents which have progressed to clinical trials.

EXPERT OPINION

microRNA have great potential to be developed into therapeutic agents due to their association with critical biological processes which govern health and disease. Utilizing microRNA sponges to target multiple microRNA associated with specific biological processes may improve their therapeutic efficacy. However, there needs to be significant improvements in delivery systems to ensure the safe delivery of microRNA to target sites and minimize systemic distribution. This currently significantly impacts the clinical translation of microRNA-based therapeutic agents.

Single nuclear RNA sequencing of terminal ileum in patients with cirrhosis demonstrates multi-faceted alterations in the intestinal barrier

Patients with cirrhosis have intestinal barrier dysfunction but the role of the individual cell types in human small intestine is unclear. We performed single-nuclear RNA sequencing (snRNAseq) in the pinch biopsies of terminal ileum of four age-matched men [56 years, healthy control, compensated, early (ascites and lactulose use) and advanced decompensated cirrhosis (ascites and rifaximin use)]. Cell type proportions, differential gene expressions, cell-type specific pathway analysis using IPA, and cellular crosstalk dynamics were compared. Stem cells, enterocytes and Paneth cells were lowest in advanced decompensation. Immune cells like naive CD4 + T cells were lowest while ITGAE + cells were highest in advanced decompensation patients. MECOM had lowest expression in stem cells in advanced decompensation. Defensin and mucin sulfation gene (PAPSS2) which can stabilize the mucus barrier expression were lowest while IL1, IL6 and TNF-related genes were significantly upregulated in the enterocytes, goblet, and Paneth cells in decompensated subjects. IPA analysis showed higher inflammatory pathways in enterocytes, stem, goblet, and Paneth cells in decompensated patients. Cellular crosstalk analysis showed that desmosome, protease-activated receptors, and cadherin-catenin complex interactions were most perturbed in decompensated patients. In summary, the snRNAseq of the human terminal ileum in 4 subjects (1 control and three cirrhosis) identified multidimensional alteration in the intestinal barrier with lower stem cells and altered gene expression focused on inflammation, mucin sulfation and cell-cell interactions with cirrhosis decompensation.

Chronic arsenic exposure-provoked biotoxicity involved in liver-microbiota-gut axis disruption in chickens based on multi-omics technologies

INTRODUCTION

Arsenic has been ranked as the most hazardous substance by the U.S. Agency for Toxic Substances and Disease Registry. Environmental arsenic exposure-evoked health risks have become a vital public health concern worldwide owing to the widespread existence of arsenic. Multi-omics is a revolutionary technique to data analysis providing an integrated view of bioinformation for comprehensively and systematically understanding the elaborate mechanism of diseases.

OBJECTIVES

This study aimed at uncovering the potential contribution of liver-microbiota-gut axis in chronic inorganic arsenic exposure-triggered biotoxicity in chickens based on multi-omics technologies.

METHODS

Forty Hy-Line W-80 laying hens were chronically exposed to sodium arsenite with a dose-dependent manner (administered with drinking water containing 10, 20, or 30 mg/L arsenic, respectively) for 42 d, followed by transcriptomics, serum non-targeted metabolome, and 16S ribosomal RNA gene sequencing accordingly.

RESULTS

Arsenic intervention induced a serious of chicken liver dysfunction, especially severe liver fibrosis, simultaneously altered ileal microbiota populations, impaired chicken intestinal barrier, further drove enterogenous lipopolysaccharides translocation via portal vein circulation aggravating liver damage. Furtherly, the injured liver disturbed bile acids (BAs) homoeostasis through strongly up-regulating the BAs synthesis key rate-limiting enzyme CYP7A1, inducing excessive serum total BAs accumulation, accompanied by the massive synthesis of primary BA-chenodeoxycholic acid. Moreover, the concentrations of secondary BAs-ursodeoxycholic acid and lithocholic acid were markedly repressed, which might involve in the repressed dehydroxylation of Ruminococcaceae and Lachnospiraceae families. Abnormal BAs metabolism in turn promoted intestinal injury, ultimately perpetuating pernicious circle in chickens. Notably, obvious depletion in the abundance of four profitable microbiota, Christensenellaceae, Ruminococcaceae, Muribaculaceae, and Faecalibacterium, were correlated tightly with this hepato-intestinal circulation process in chickens exposed to arsenic.

CONCLUSION

Our study demonstrates that chronic inorganic arsenic exposure evokes liver-microbiota-gut axis disruption in chickens and establishes a scientific basis for evaluating health risk induced by environmental pollutant arsenic.

Liver cirrhosis and complications from the perspective of dysbiosis

The gut-liver axis refers to the intimate relationship and rigorous interaction between the gut and the liver. The intestinal barrier's integrity is critical for maintaining liver homeostasis. The liver operates as a second firewall in this interaction, limiting the movement of potentially dangerous compounds from the gut and, as a result, contributing in barrier management. An increasing amount of evidence shows that increased intestinal permeability and subsequent bacterial translocation play a role in liver damage development. The major pathogenic causes in cirrhotic individuals include poor intestinal permeability, nutrition, and intestinal flora dysbiosis. Portal hypertension promotes intestinal permeability and bacterial translocation in advanced liver disease, increasing liver damage. Bacterial dysbiosis is closely related to the development of cirrhosis and its related complications. This article describes the potential mechanisms of dysbiosis in liver cirrhosis and related complications, such as spontaneous bacterial peritonitis, hepatorenal syndrome, portal vein thrombosis, hepatic encephalopathy, and hepatocellular carcinoma, using dysbiosis of the intestinal flora as an entry point.

Contributing roles of mitochondrial dysfunction and hepatocyte apoptosis in liver diseases through oxidative stress, post-translational modifications, inflammation, and intestinal barrier dysfunction

This review provides an update on recent findings from basic, translational, and clinical studies on the molecular mechanisms of mitochondrial dysfunction and apoptosis of hepatocytes in multiple liver diseases, including but not limited to alcohol-associated liver disease (ALD), metabolic dysfunction-associated steatotic liver disease (MASLD), and drug-induced liver injury (DILI). While the ethanol-inducible cytochrome P450-2E1 (CYP2E1) is mainly responsible for oxidizing binge alcohol via the microsomal ethanol oxidizing system, it is also responsible for metabolizing many xenobiotics, including pollutants, chemicals, drugs, and specific diets abundant in n-6 fatty acids, into toxic metabolites in many organs, including the liver, causing pathological insults through organelles such as mitochondria and endoplasmic reticula. Oxidative imbalances (oxidative stress) in mitochondria promote the covalent modifications of lipids, proteins, and nucleic acids through enzymatic and non-enzymatic mechanisms. Excessive changes stimulate various post-translational modifications (PTMs) of mitochondrial proteins, transcription factors, and histones. Increased PTMs of mitochondrial proteins inactivate many enzymes involved in the reduction of oxidative species, fatty acid metabolism, and mitophagy pathways, leading to mitochondrial dysfunction, energy depletion, and apoptosis. Unique from other organelles, mitochondria control many signaling cascades involved in bioenergetics (fat metabolism), inflammation, and apoptosis/necrosis of hepatocytes. When mitochondrial homeostasis is shifted, these pathways become altered or shut down, likely contributing to the death of hepatocytes with activation of inflammation and hepatic stellate cells, causing liver fibrosis and cirrhosis. This review will encapsulate how mitochondrial dysfunction contributes to hepatocyte apoptosis in several types of liver diseases in order to provide recommendations for targeted therapeutics.

Splenectomy ameliorates liver cirrhosis by restoring the gut microbiota balance

BACKGROUND

Dysbiosis of gut microbiota is frequent in liver cirrhosis (LC) patients, and splenectomy (SP) has been reported to improve LC. Herein, we report the effects of SP on gut microbiota, especially on Veillonella parvula, a Gram-negative coccus of the gastrointestinal tract, in LC mice, and the underlying mechanism.

METHODS

LC mice models were induced by tail vein injection of concanavalin A (ConA), followed by SP. 16 s rRNA sequencing was conducted to analyze the effects of ConA induction and SP on mouse gut microbiota and the gene expression affected by gut microbiota. LC mice receiving SP were gavaged with Veillonella parvula. Likewise, hepatic stellate cells (HSC) and hepatocytes (HC) were induced with conditioned medium (CM) of Veillonella parvula.

RESULTS

SP alleviated LC in mice by restoring gut barrier function and maintaining gut microbiota balance, with Veillonella as the key genus. The Veillonella parvula gavage on LC mice reversed the ameliorative effect of SP. The CM of Veillonella parvula promoted the activation of HSC and the release of IL-6, IL-1β, and TNF-α. Also, the CM of Veillonella parvula induced HC pyroptosis and the release of ALT and AST. Veillonella parvula represented an imbalance in the gut microbiota, thus enhancing gut-derived endotoxins in the liver with the main target being Tlr4/Nlrp3. Inhibition of Tlr4 blocked Veillonella parvula-induced HC damage, HSC activation, and subsequent LC progression.

CONCLUSION

SP-mediated gut microbiota regulation ameliorates ConA-related LC progression by inhibiting Tlr4/Nlrp3 in the liver.

Lower free triiodothyronine (fT3) levels in cirrhosis are linked to systemic inflammation, higher risk of acute-on-chronic liver failure, and mortality

Background & Aims

Advanced chronic liver disease (ACLD) may affect thyroid hormone homeostasis. We aimed to analyze the pituitary-thyroid axis in ACLD and the prognostic value of free triiodothyronine (fT3).

Methods

Patients with ACLD (liver stiffness measurement [LSM] ≥10 kPa) undergoing hepatic venous pressure gradient (HVPG) measurement between June 2009 and September 2022 and available fT3 levels were included. Clinical stages of ACLD were defined as follows: probable ACLD (pACLD; LSM ≥10 kPa and HVPG ≤5 mmHg), S0 (mild portal hypertension [PH]; HVPG 6-9 mmHg), S1 (clinically significant PH), S2 (clinically significant PH with varices), S3 (past variceal bleeding), S4 (past/current non-bleeding hepatic decompensation), and S5 (further decompensation).

Results

Among 297 patients with ACLD, 129 were compensated (pACLD, n = 10; S0, n = 33; S1, n = 42; S2, n = 44), whereas 168 were decompensated (S3, n = 12; S4, n = 97; S5, n = 59). Median levels of thyroid-stimulating hormone (TSH) numerically increased with progressive ACLD stage (from 1.2 μIU/ml [pACLD] to 1.5 μIU/ml [S5]; p = 0.152), whereas fT3 decreased (from 3.2 pg/ml [pACLD] to 2.5 pg/ml [S5]; p <0.001). Free thyroxin levels remained unchanged (p = 0.338). TSH (aB 0.45; p = 0.046) and fT3 (aB -0.17; p = 0.048) were independently associated with systemic C-reactive protein levels. Lower fT3 was linked to higher risk of (further) decompensation (adjusted subdistribution hazard ratio [asHR] 0.60; 95% CI 0.37-0.97; p = 0.037), acute-on-chronic liver failure (asHR 0.19; 95% CI 0.08-0.49; p <0.001) and liver-related death (asHR 0.14; 95% CI 0.04-0.51; p = 0.003).

Conclusions

Increasing TSH and declining fT3 levels are observed with progressive ACLD stages. The association of TSH and fT3 with systemic inflammation suggests a liver disease-associated non-thyroidal illness syndrome. Lower fT3 levels in patients with ACLD indicate increased risk for decompensation, acute-on-chronic liver failure, and liver-related death.

Impact and Implications

In a large well-characterized cohort of patients with advanced chronic liver disease (ACLD), we found a decline of free triiodothyronine (fT3) throughout the clinical stages of ACLD, paralleled by a numerical increase of thyroid-stimulating hormone (TSH). This suggests a progressive development of a non-thyroidal illness syndrome in association with ACLD severity. Importantly, C-reactive protein independently correlated with TSH and fT3, linking thyroid dysbalance in ACLD to systemic inflammation. Lower fT3 indicated an increased risk for subsequent development of hepatic decompensation, acute-on-chronic liver failure, and liver-related death.

Clinical trial number

Vienna Cirrhosis Study (VICIS; NCT: NCT03267615).

Role of the immune system in liver transplantation and its implications for therapeutic interventions

Liver transplantation (LT) stands as the gold standard for treating end-stage liver disease and hepatocellular carcinoma, yet postoperative complications continue to impact survival rates. The liver's unique immune system, governed by a microenvironment of diverse immune cells, is disrupted during processes like ischemia-reperfusion injury posttransplantation, leading to immune imbalance, inflammation, and subsequent complications. In the posttransplantation period, immune cells within the liver collaboratively foster a tolerant environment, crucial for immune tolerance and liver regeneration. While clinical trials exploring cell therapy for LT complications exist, a comprehensive summary is lacking. This review provides an insight into the intricacies of the liver's immune microenvironment, with a specific focus on macrophages and T cells as primary immune players. Delving into the immunological dynamics at different stages of LT, we explore the disruptions after LT and subsequent immune responses. Focusing on immune cell targeting for treating liver transplant complications, we provide a comprehensive summary of ongoing clinical trials in this domain, especially cell therapies. Furthermore, we offer innovative treatment strategies that leverage the opportunities and prospects identified in the therapeutic landscape. This review seeks to advance our understanding of LT immunology and steer the development of precise therapies for postoperative complications.

Alterations in gut virome are associated with cognitive function and minimal hepatic encephalopathy cross-sectionally and longitudinally in cirrhosis

Cognitive dysfunction due to minimal hepatic encephalopathy (MHE) adversely impacts patients with cirrhosis and more precise therapies are needed. Gut-brain axis changes are therapeutic targets, but prior studies have largely focused on bacterial changes. Our aim was to determine linkages between individual cognitive testing results and bacteria with the virome using a cross-sectional and longitudinal approach. We included cross-sectional (n = 138) and longitudinal analyses (n = 36) of patients with cirrhosis tested using three cognitive modalities, which were psychometric hepatic encephalopathy score (PHES), inhibitory control test (ICT), Stroop, and all three. Stool metagenomics with virome and bacteriome were analyzed studied cross-sectionally and in a subset followed for development/reversal of MHE repeated at 6 months (longitudinally only using PHES). Cross-sectional: We found no significant changes in α/β diversity in viruses or bacteria regardless of cognitive testing. Cognitively impaired patients were more likely to have higher relative abundance of bacteriophages linked with Streptococcus, Faecalibacterium, and Lactobacillus, which were distinct based on modality. These were also linked with cognition on correlation networks. Longitudinally, 27 patients remained stable while 9 changed their MHE status. Similar changes in phages that are linked with Streptococcus, Faecalibacterium, and Lactobacillus were seen. These phages can influence ammonia, lactate, and short-chain fatty acid generation, which are neuro-active. In conclusion, we found linkages between bacteriophages and cognitive function likely due to impact on bacteria that produce neuroactive metabolites cross-sectionally and longitudinally. These findings could help explore bacteriophages as options to influence treatment for MHE in cirrhosis.

Moringa oleifera Leaves Protein Enhances Intestinal Permeability by Activating TLR4 Upstream Signaling and Disrupting Tight Junctions

Changes in intestinal mucosal barrier permeability lead to antigen sensitization and mast cell-mediated allergic reactions, which are considered to play important roles in the occurrence and development of food allergies. It has been suggested that protein causes increased intestinal permeability via mast cell degranulation, and we investigated the effect of camellia Moringa oleifera leaves protein on intestinal permeability and explored its role in the development of food allergies. The current study investigated the effect of M. oleifera leaves protein on intestinal permeability through assessments of transepithelial electrical resistance (TEER) and transmembrane transport of FITC-dextran by Caco-2 cells. The expression levels of Toll-like receptor 4 (TLR4), IL-8, Occludin, Claudin-1, and perimembrane protein family (ZO-1) were detected by real-time PCR and Western blotting. The effect of M. oleifera leaves protein on intestinal permeability was verified in mice in vivo. The serum fluorescence intensity was measured using the FITC-dextran tracer method, and the expression of tight junction proteins was detected using Western blotting. The results showed that M. oleifera leaves protein widened the gaps between Caco-2 cells, reduced transmembrane resistance, and increased permeability. This protein also reduced the mRNA and protein levels of Occludin, Claudin-1, and ZO-1. Animal experiments showed that intestinal permeability was increased, and that the expression of the tight junction proteins Occludin and Claudin-1 were downregulated in mice. This study shows that M. oleifera leaves protein has components that increase intestinal permeability, decrease tight junction protein expression, promote transmembrane transport in Caco-2 cells, and increase intestinal permeability in experimental animals. The finding that M. oleifera leaves active protein increases intestinal permeability suggests that this protein may be valuable for the prevention, diagnosis, and treatment of M. oleifera leaves allergy.

Prospective therapeutics for intestinal and hepatic fibrosis

Currently, there are no effective therapies for intestinal and hepatic fibrosis representing a considerable unmet need. Breakthroughs in pathogenesis have accelerated the development of anti-fibrotic therapeutics in recent years. Particularly, with the development of nanotechnology, the harsh environment of the gastrointestinal tract and inaccessible microenvironment of fibrotic lesions seem to be no longer considered a great barrier to the use of anti-fibrotic drugs. In this review, we comprehensively summarize recent preclinical and clinical studies on intestinal and hepatic fibrosis. It is found that the targets for preclinical studies on intestinal fibrosis is varied, which could be divided into molecular, cellular, and tissues level, although little clinical trials are ongoing. Liver fibrosis clinical trials have focused on improving metabolic disorders, preventing the activation and proliferation of hepatic stellate cells, promoting the degradation of collagen, and reducing inflammation and cell death. At the preclinical stage, the therapeutic strategies have focused on drug targets and delivery systems. At last, promising remedies to the current challenges are based on multi-modal synergistic and targeted delivery therapies through mesenchymal stem cells, nanotechnology, and gut-liver axis providing useful insights into anti-fibrotic strategies for clinical use.

Lactulose in cirrhosis: Current understanding of efficacy, mechanism, and practical considerations

HE is a complication of cirrhosis characterized by neuropsychiatric and motor dysfunction, and results in decreased quality of life and increased mortality. Lactulose is a synthetic disaccharide used to treat HE since 1966, though many questions about its use remain unanswered. Lactulose reverses minimal HE, prevents overt HE, improves quality of life, increases the rate of recovery from overt HE, and improves survival rates. Lactulose's clinical effect appears to be derived from its impact on intestinal microbes, likely a result of its enteric acidifying effect, positive pressure on beneficial taxa, and improvement of gut barrier function. There are several practical considerations with lactulose including (1) a need to avoid excessive bowel movements and subsequent dehydration, (2) treatment titration protocols need further investigation, (3) baseline or treatment-induced gastrointestinal side effects limit adherence in some cases, and (4) the utility of monitoring stool consistency or pH remains unknown. Further research is needed to optimize our use of this effective treatment for HE.

Effect of Artificial Liver Support Systems on Gut Microbiota in Patients with HBV-Related Acute-on-Chronic Liver Failure

Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is a rare and severe form of end-stage liver disease with high mortality; gut microbes are strongly associated with the development of this severe liver disease but the exact association is unclear. Artificial liver support systems (ALSS) are clinically important in prolonging the waiting time for liver transplantation and in aiding drug therapy to achieve remission. The aim of this study was to investigate the effect of ALSS on the abundance and diversity of microorganisms in the gut of HBV-ACLF patients. In this study, 109 stool samples were collected from patients with hepatitis B virus-associated acute chronic liver failure (HBV-ACLF) for 16S rRNA sequencing. Among them, 44 samples were from patients treated with ALSS therapy as an adjunct to standard medical treatment (SMT) and 65 were from patients receiving SMT only. Analysis of the sequencing results suggested that there were significant differences in the abundance and diversity of gut microbiota between the with-ALSS and without-ALSS groups (p < 0.05). The operational taxonomic units and Shannon indexes indicated that the diversity and abundance of the gut microbiome, while decreasing after the first ALSS treatment, gradually increased after an increase in the number of ALSS therapies. The overall proportion of HBV-ACLF patients with coinfection was 27.59%; the coinfection can reduce the abundance of the Bacteroidetes phylum in the microbiome significantly whereas Proteobacteria were highly enriched. After ALSS therapy, HBV-ACLF patients had a decrease in potentially harmful bacteria, an increase in potentially beneficial bacteria, an increase in the diversity of the intestinal microbiota, and the intestinal microecological disorders were corrected to a certain extent. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBIL) levels, as well as the international normalized ratio (INR), showed a decreasing trend whereas plasminogen activity (PTA) increased and the condition of patients with HBV-ACLF progressed in a favorable direction. In addition, the abundance of Blautia and Coprococcus was negatively correlated with TBIL and INR, positively correlated with PTA, and positively correlated with disease recovery. Our study shows that ALSS can alter the composition of the gut microbiota and have an ameliorating effect on the gut microecological imbalance in HBV-ACLF patients. It is worth mentioning that Blautia and Coprococcus may have great potential as biomarkers.

An impaired pituitary-adrenal signalling axis in stable cirrhosis is linked to worse prognosis

Background & Aims

Inadequate adrenal function has been described in patients with cirrhosis. We investigated (i) the pituitary-adrenal axis at different clinical stages and (ii) the clinical impact of decreased serum cortisol levels in stable patients with advanced chronic liver disease (ACLD).

Methods

We included 137 outpatients with ACLD undergoing hepatic venous pressure gradient (HVPG) measurement in the prospective VICIS study (NCT03267615). Patients were stratified into six clinical stages: S0: subclinical portal hypertension (PH) (HVPG 6-9 mmHg), S1: clinically significant PH (HVPG ≥10 mmHg) without varices, S2: presence of varices, S3: previous variceal bleeding, S4: previous non-bleeding decompensation, and S5: further decompensation.

Results

Fifty-one patients had compensated ACLD (S0: n = 13; S1: n = 12; S2: n = 26), whereas 86 patients had decompensated ACLD (S3: n = 7; S4: n = 46; S5: n = 33). Serum total cortisol (t-Cort) showed a strong correlation with estimated serum free cortisol (f-Cort; Spearman's ρ: 0.889). With progressive clinical stage, median ACTH levels (from S0: 44.0 pg/ml to S5: 20.0 pg/ml; p = 0.006), t-Cort (from S0: 13.9 μg/dl to S5: 9.2 μg/dl; p = 0.091), and cortisol binding globulin (from S0: 49.3 μg/ml to S5: 38.9 μg/ml; p <0.001) decreased, whereas f-Cort (p = 0.474) remained unchanged. Lower t-Cort levels independently predicted bacterial infections (asHR: 1.11; 95% CI: 1.04-1.19; p = 0.002), further decompensation (asHR: 1.08; 95% CI: 1.02-1.12; p = 0.008), acute-on-chronic liver failure (ACLF; asHR: 1.11; 95% CI: 1.04-1.19; p = 0.002), and liver-related death (asHR: 1.09; 95% CI: 1.01-1.18; p = 0.045).

Conclusions

The pituitary-ACTH-adrenal-cortisol axis is progressively suppressed with increasing severity of cirrhosis. Lower t-Cort is an independent risk factor for bacterial infections, further decompensation of ACLF, and liver-related mortality-even in stable outpatients with cirrhosis.

Clinical trial number

Vienna Cirrhosis Study (VICIS; NCT: NCT03267615).

Impact and Implications

In a cohort of stable outpatients, we observed progressive suppression of the pituitary-adrenal axis with increasing clinical stage of advanced chronic liver disease (ACLD). Increased levels of bile acids and systemic inflammation (assessed by interleukin-6 levels) could be involved in this suppression. Serum total cortisol (t-Cort) was strongly correlated with serum free cortisol (f-Cort) and lower t-Cort levels were independently associated with a higher risk of adverse clinical outcomes, including bacterial infections, further decompensation, acute-on-chronic liver failure, and liver-related death.

Bacterial translocation occurs early in cirrhosis and triggers a selective inflammatory response

BACKGROUND

Experimental data suggest that bacterial translocation (BT) promotes systemic inflammation, portal hypertension, and circulatory dysfunction in advanced chronic liver disease (ACLD).

METHODS

Patients with ACLD undergoing hepatic venous pressure gradient (HVPG) measurement and absence of acute decompensation or infections were included (n = 249). Serum biomarkers of BT (lipopolysaccharide [LPS], lipoteichoic acid [LTA], bacterial DNA [bactDNA]), systemic inflammation and markers of circulatory dysfunction were assessed. T-cell subsets in intestinal biopsies (n = 7 ACLD, n = 4 controls) were analyzed by flow cytometry.

RESULTS

Patients had a median HVPG of 18 (12-21) mmHg and 56% had decompensated ACLD. LPS (0.04 [0.02-0.06] vs. 0.64 [0.30-1.06] EU/mL), LTA (4.53 [3.58-5.97] vs. 43.2 [23.2-109] pg/mL), and detection of bactDNA (≥ 5 pg/mL; 5% vs. 41%) were markedly higher in patients with ACLD than healthy controls (n = 40; p < 0.001) but were similar between different clinical stages of compensated and decompensated ACLD and displayed no meaningful correlation with HVPG and systemic hemodynamics. TNF-α and IL-10 correlated with LPS (Spearman's rs = 0.523, p < 0.001/rs = 0.143, p = 0.024) but not with LTA. Presence of bactDNA was associated with higher LPS (0.54 [0.28-0.95] vs. 0.88 [0.32-1.31] EU/mL, p = 0.001) and TNF-α (15.3 [6.31-28.1] vs. 20.9 [13.8-32.9] pg/mL). Patients with ACLD exhibited a decreased CD4:CD8-ratio and increased TH1-cells in the intestinal mucosa as compared to controls. During a median FU of 14.7 (8.20-26.5) months, bacterial antigens did not predict decompensation or liver-related death (in contrast to HVPG, IL-6, and MAP) as well as infections at 24 months.

CONCLUSION

BT occurs already in early ACLD stages and triggers a systemic inflammatory response via TNF-α and IL-10. Interestingly, BT markers showed no clear correlation with portal hypertension and circulatory dysfunction in patients with stable ACLD.

CLINICAL TRIAL NUMBER

NCT03267615.

Role of Oral Health, Frailty, and Minimal Hepatic Encephalopathy in the Risk of Hospitalization: A Prospective Multi-Center Cohort of Outpatients With Cirrhosis

BACKGROUND & AIMS

Hospitalizations are a sentinel event in cirrhosis; however, the changing demographics in patients with cirrhosis require updated hospitalization prediction models. Periodontitis is a risk factor for liver disease and potentially progression. The aim of this study was to determine factors, including poor oral health, associated with 3-month hospitalizations in a multi-center cohort of outpatients with cirrhosis.

METHODS

North American Consortium for Study of End-stage Liver Disease (NACSELD-3), a new study cohort, recruits outpatients with cirrhosis. Cirrhosis details, demographics, minimal hepatic encephalopathy (MHE), frailty, and comorbid conditions including oral health were collected. All patients were followed for 3 months for nonelective hospitalizations. Multi-variable models were created for this outcome using demographics, cirrhosis details, oral health, MHE, frailty, and comorbid conditions with K-fold internal validation using 25%/75% split.

RESULTS

A total of 442 outpatients (70% men; 37% compensated; Model for End-stage Liver Disease-Sodium, 12; 42% ascites; and 33% prior HE) were included. MHE was found in 70%, frailty in 10%; and both in 8%. In terms of oral health, 15% were edentulous and 10% had prior periodontitis. Regarding 3-month hospitalizations, 14% were admitted for mostly liver-related reasons. These patients were more likely to be decompensated with higher cirrhosis complications, MHE, frailty and periodontitis history. Multi-variable analysis showed prior periodontitis (P = .026), composite MHE + frailty score (P = .0016), ascites (P = .004), prior HE (P = .008), and hydrothorax (P = .004) were associated with admissions using the training and validation subsets.

CONCLUSIONS

In a contemporaneous, prospective, multi-center cohort study in outpatients with cirrhosis, poor oral health is significantly associated with 3-month hospitalizations independent of portal hypertensive complications, MHE, and frailty. Potential strategies to reduce hospitalizations should consider oral evaluation in addition to MHE and frailty assessment in practice pathways.

Immunological factors in cirrhosis diseases from a bibliometric point of view

BACKGROUND

Cirrhosis results from persistent liver injury that leads to liver fibrosis. Immunological factors play important regulatory roles in the development and progression of cirrhosis. Bibliometrics is one of the most commonly used methods for systematic evaluation of a field of study. To date, there are no bibliometric studies on the role of immunological factors in cirrhosis.

AIM

To provide a comprehensive overview of the knowledge structure and research hotspots of immunological factors in cirrhosis.

METHODS

We retrieved publications related to immunological factors in cirrhosis between 2003 to 2022 from the Web of Science Core Collection database on December 7, 2022. The search strategy was TS = ((Liver Cirrhosis OR hepatic cirrhosis OR liver fibrosis) AND (Immunologic* Factor* OR Immune Factor* OR Immunomodulator* OR Biological Response Modifier* OR Biomodulator*)). Only original articles and reviews were included. A total of 2873 publications were analyzed using indicators of publication and citation metrics, countries, institutes, authors, journals, references, and keywords by CiteSpace and VOSviewer.

RESULTS

A total of 5104 authors from 1173 institutions across 51 countries published 2873 papers on cirrhosis and immunological factors in 281 journals. In the past 20 years, the increasing number of related annual publications and citations indicates that research on immunological factors in cirrhosis has become the focus of attention and has entered a period of accelerated development. The United States (781/27.18%), China (538/18.73%), and Germany (300/10.44%) were the leading countries in this field. Most of the top 10 authors were from the United States (4) and Germany (3), with Gershwin ME contributing the most related articles (42). World Journal of Gastroenterology was the most productive journal, whereas Hepatology was the most co-cited journal. Current research hotspots regarding immunological factors in cirrhosis include fibrosis, cirrhosis, inflammation, liver fibrosis, expression, hepatocellular carcinoma, activation, primary biliary cirrhosis, disease, and hepatic stellate cells. Burst keywords (e.g., epidemiology, gut microbiota, and pathways) represent research frontiers that have attracted the interest of researchers in recent years.

CONCLUSION

This bibliometric study comprehensively summarizes the research developments and directions of immunological factors in cirrhosis, providing new ideas for promoting scientific research and clinical applications.

The regulatory role of bile acid microbiota in the progression of liver cirrhosis

Bile acids (BAs) are synthesized in liver tissue from cholesterol and are an important endocrine regulator and signaling molecule in the liver and intestine. It maintains BAs homeostasis, and the integrity of intestinal barrier function, and regulates enterohepatic circulation in vivo by modulating farnesoid X receptors (FXR) and membrane receptors. Cirrhosis and its associated complications can lead to changes in the composition of intestinal micro-ecosystem, resulting in dysbiosis of the intestinal microbiota. These changes may be related to the altered composition of BAs. The BAs transported to the intestinal cavity through the enterohepatic circulation are hydrolyzed and oxidized by intestinal microorganisms, resulting in changes in their physicochemical properties, which can also lead to dysbiosis of intestinal microbiota and overgrowth of pathogenic bacteria, induction of inflammation, and damage to the intestinal barrier, thus aggravating the progression of cirrhosis. In this paper, we review the discussion of BAs synthesis pathway and signal transduction, the bidirectional regulation of bile acids and intestinal microbiota, and further explore the role of reduced total bile acid concentration and dysregulated intestinal microbiota ratio in the development of cirrhosis, in order to provide a new theoretical basis for the clinical treatment of cirrhosis and its complications.

Gut microbial profile of treatment-naive patients with primary biliary cholangitis

Background and aims

The pathogenesis of primary biliary cholangitis (PBC) is associated with alterations of gut microbiota. We compared the gut microbiota of PBC patients and healthy controls from Zhejiang Province and assessed the use of these data for the diagnosis of PBC.

Methods

First, 16S rRNA gene sequencing was used to characterize the gut microbiota of treatment-naive PBC patients (n=25) and matched healthy controls (n=25). Then, the value of gut microbiota composition for the diagnosis of PBC and assessment of PBC severity was determined.

Results

The gut microbiota of PBC patients had lower diversity based on three different metrics of alpha-diversity (ace, Chao1, and observed features) and fewer overall genera (all p<0.01). PBC patients had significant enrichment of four genera and significant depletion of eight genera. We identified six amplicon sequence variants (Serratia, Oscillospirales, Ruminococcaceae, Faecalibacterium, Sutterellaceae, and Coprococcus) as optimal biomarkers to distinguish PBC patients from controls based on receiver operating characteristic analysis (area under the curve [AUC] = 0.824). PBC patients who were anti-gp210-positive had lower levels of Oscillospiraceae than those who were anti-gp210-negative. KEGG functional annotation suggested the major changes in the gut microbiota of PBC patients were related to lipid metabolism and biosynthesis of secondary metabolites.

Conclusion

We characterized the gut microbiota of treatment-naive PBC patients and healthy controls from Zhejiang Province. The PBC patients had significant alterations in their gut microbiota, suggesting that gut microbiota composition could be useful as a non-invasive tool for the diagnosis of PBC.

The Influence of Gut Microbiota on Oxidative Stress and the Immune System

The human gastrointestinal tract is home to a complex microbial community that plays an important role in the general well-being of the entire organism. The gut microbiota generates a variety of metabolites and thereby regulates many biological processes, such as the regulation of the immune system. In the gut, bacteria are in direct contact with the host. The major challenge here is to prevent unwanted inflammatory reactions on one hand and on the other hand to ensure that the immune system can be activated when pathogens invade. Here the REDOX equilibrium is of utmost importance. This REDOX equilibrium is controlled by the microbiota either directly or indirectly via bacterial-derived metabolites. A balanced microbiome sorts for a stable REDOX balance, whereas dysbiosis destabilizes this equilibrium. An imbalanced REDOX status directly affects the immune system by disrupting intracellular signaling and promoting inflammatory responses. Here we (i) focus on the most common reactive oxygen species (ROS) and (ii) define the transition from a balanced REDOX state to oxidative stress. Further, we (iii) describe the role of ROS in regulating the immune system and inflammatory responses. Thereafter, we (iv) examine the influence of microbiota on REDOX homeostasis and how shifts in pro- and anti-oxidative cellular conditions can suppress or promote immune responses or inflammation.

Dysregulated biomarkers of innate and adaptive immunity predict infections and disease progression in cirrhosis

Background & Aims

Cirrhosis-associated immune dysfunction (CAID) affects both innate and adaptive immunity. This study investigated the complement system, immunoglobulins, and acute-phase proteins and their prognostic relevance in patients with advanced chronic liver disease (ACLD).

Methods

Patients with ACLD (hepatic venous pressure gradient [HVPG] ≥6 mmHg) but without acute decompensation/infections were characterised by HVPG and by clinical EASL stages: compensated (cACLD; S0-2) vs. decompensated ACLD (dACLD) with previous variceal bleeding (S3), non-bleeding decompensation (S4), or further decompensation (S5). Complement factors (C3c, C4, CH50), immunoglobulins (IgA, IgM, IgG, IgG1-4), acute-phase proteins and systemic inflammation biomarkers (white blood cells, C-reactive protein, IL-6, procalcitonin) were measured.

Results

A total of 245 patients (median model for end-stage liver disease score: 11 [9-15], median HVPG: 17 [12-21] mmHg) were included with 150 (61%) presenting dACLD. Complement levels and activity significantly decreased in dACLD substages S4 and S5 (p <0.001). Total IgA/IgM/IgG and IgG1-4 subtype levels increased in patients with dACLD (all p <0.05). Complement and immunoglobulin levels correlated negatively and positively, respectively, with systemic inflammation (all p <0.05). High IgG-1 (adjusted hazard ratio per 100 mg/dl: 1.12, 1.04-1.19, p = 0.002) and IL-6 (adjusted hazard ratio: 1.03, 1.00-1.05, p = 0.023) levels predicted the development of infections during follow-up. High IgA (stratified by median; log-rank p <0.001), high IgG1 (log-rank p = 0.043) and low C3c (log-rank p = 0.003) indicated a higher risk of first/further decompensation or liver-related death (composite endpoint). Next to HVPG and IL-6, low C3c (adjusted hazard ratio per mg/dl: 0.99, 0.97-0.99, p = 0.040) remained independently associated with the composite endpoint on multivariate Cox regression analysis.

Conclusions

Complement levels and immunoglobulins may serve as surrogates of cirrhosis-associated immune dysfunction and associate with cirrhosis severity and systemic inflammation. Low complement C3c predicted decompensation and liver-related death, whereas high IgG-1 indicated an increased risk for infections.

Impact and Implications

Patients with cirrhosis are at increased risk for infections, which worsen their prognosis. We found a significant dysregulation of several essential components of the immune system that was linked to disease severity and indicated a risk for infections and other complications. Simple blood tests identify patients at particularly high risk, who may be candidates for preventive measures.

Clinical Trials Registration

This study is registered at ClinicalTrials.gov (NCT03267615).

Gut Microbiota and Infectious Complications in Advanced Chronic Liver Disease: Focus on Spontaneous Bacterial Peritonitis

Liver cirrhosis is a chronic disease that can be complicated by episodes of decompensation such as variceal bleeding, hepatic encephalopathy, ascites, and jaundice, with subsequent increased mortality. Infections are also among the most common complications in cirrhotic patients, mostly due to a defect in immunosurveillance. Among them, one of the most frequent is spontaneous bacterial peritonitis (SBP), defined as the primary infection of ascitic fluid without other abdominal foci. SBP is mainly induced by Gram-negative bacteria living in the intestinal tract, and translocating through the intestinal barrier, which in cirrhotic patients is defective and more permeable. Moreover, in cirrhotic patients, the intestinal microbiota shows an altered composition, poor in beneficial elements and enriched in potentially pathogenic ones. This condition further promotes the development of leaky gut and increases the risk of SBP. The first-line treatment of SBP is antibiotic therapy; however, the antibiotics used have a broad spectrum of action and may adversely affect the composition of the gut microbiota, worsening dysbiosis. For this reason, the future goal is to use new therapeutic agents that act primarily on the gut microbiota, selectively modulating it, or on the intestinal barrier, reducing its permeability. In this review, we aim to describe the reciprocal relationship between gut microbiota and SBP, focusing on pathogenetic aspects but also on new future therapies.

A novel alternative strategy for monitoring and insight into liver fibrosis progression: The combination of surface-enhanced Raman spectroscopy (SERS) and gut microbiota

Nowadays, the studies on the interaction and relationship between the intestinal microorganisms and liver diseases are increasing. However, it is still a huge challenge for the in-depth investigation and dynamic monitoring of such a complex network. Herein, a significant discovery was made. A strong association between gut microbial structural and functional genomics and SERS spectra of hepatocytes were revealed. Based on the study of gut microbes and SERS spectra, complementary information could be provided for the mechanism analysis of related diseases. Liver fibrosis, a chronic liver disease that lack specific cure was thus comprehensive studied. Liver targeting gold nanoparticle dimers were prepared as the SERS tags, and abundant SERS peak signals were acquired. Meanwhile, the gut microbiomes were also comparative studied. The changes of carbohydrates and lipids in liver cells were observed at the early stages of liver fibrosis, and TLR4 (toll-like receptors 4) was activated to elicit immune responses. Then again, oxidative stress, endotoxin and serum inflammatory factors were the major observations at the late stages. The SERS signals and the microbiome analysis were well confirmed and complemented each other, which suggested that the detection strategy could be another valuable method for the "gut-liver axis" study.

Longitudinal transkingdom gut microbial approach towards decompensation in outpatients with cirrhosis

OBJECTIVE

First decompensation development is a critical milestone that needs to be predicted. Transkingdom gut microbial interactions, including archaeal methanogens, may be important targets and predictors but a longitudinal approach is needed.

DESIGN

Cirrhosis outpatients who provided stool twice were included. Group 1: compensated, group 2: 1 decompensation (decomp), group 3: >1 decompensationwere followed and divided into those who remained stable or decompensated. Bacteria, viral and archaeal presence, α/β diversity and taxa changes over time adjusted for clinical variables were analysed. Correlation networks between kingdoms were analysed.

RESULTS

157 outpatients (72 group 1, 33 group 2 and 52 group 3) were followed and 28%-47% developed outcomes. Baseline between those who remained stable/developed outcome: While no α/β diversity differences were seen, commensals were lower and pathobionts were higher in those who decompensated. After decompensation: those experiencing their first decompensation showed greater decrease in α/β-diversity, bacterial change (↑Lactobacillus spp, Streptococcus parasanguinis and ↓ beneficial Lachnospiraceae and Eubacterium hallii) and viral change (↑Siphoviridae, ↓ Myoviridae) versus those with further decompensation. Archaea: 19% had Methanobacter brevii, which was similar between/within groups. Correlation networks: Baseline archaeal-viral-bacterial networks were denser and more homogeneous in those who decompensated versus the rest. Archaea-bacterial correlations collapsed post first decompensation. Lactobacillus phage Lc Nu and C2-like viruses were negatively linked with beneficial bacteria.

CONCLUSION

In this longitudinal study of cirrhosis outpatients, the greatest transkingdom gut microbial changes were seen in those reaching the first decompensation, compared with subsequent decompensating events. A transkingdom approach may refine prediction and provide therapeutic targets to prevent cirrhosis progression.

Herbal formula BaWeiBaiDuSan alleviates polymicrobial sepsis-induced liver injury via increasing the gut microbiota Lactobacillus johnsonii and regulating macrophage anti-inflammatory activity in mice

Sepsis-induced liver injury (SILI) is an important cause of septicemia deaths. BaWeiBaiDuSan (BWBDS) was extracted from a formula of Panax ginseng C. A. Meyer, Lilium brownie F. E. Brown ex Miellez var. viridulum Baker, Polygonatum sibiricum Delar. ex Redoute, Lonicera japonica Thunb., Hippophae rhamnoides Linn., Amygdalus Communis Vas, Platycodon grandiflorus (Jacq.) A. DC., and Cortex Phelloderdri. Herein, we investigated whether the BWBDS treatment could reverse SILI by the mechanism of modulating gut microbiota. BWBDS protected mice against SILI, which was associated with promoting macrophage anti-inflammatory activity and enhancing intestinal integrity. BWBDS selectively promoted the growth of Lactobacillus johnsonii (L. johnsonii) in cecal ligation and puncture treated mice. Fecal microbiota transplantation treatment indicated that gut bacteria correlated with sepsis and was required for BWBDS anti-sepsis effects. Notably, L. johnsonii significantly reduced SILI by promoting macrophage anti-inflammatory activity, increasing interleukin-10+ M2 macrophage production and enhancing intestinal integrity. Furthermore, heat inactivation L. johnsonii (HI-L. johnsonii) treatment promoted macrophage anti-inflammatory activity and alleviated SILI. Our findings revealed BWBDS and gut microbiota L. johnsonii as novel prebiotic and probiotic that may be used to treat SILI. The potential underlying mechanism was at least in part, via L. johnsonii-dependent immune regulation and interleukin-10+ M2 macrophage production.

A double-blind randomized placebo-controlled trial of albumin in outpatients with hepatic encephalopathy: HEAL study

BACKGROUND & AIMS

Even after recovery from overt hepatic encephalopathy (HE), minimal HE (MHE), which impairs quality of life (QoL), can persist. A double-blind, placebo-controlled randomized clinical trial was performed to determine the impact of albumin vs. saline on MHE and QoL in individuals with prior HE already on standard of care.

METHODS

Outpatients with cirrhosis and prior HE, MHE and hypoalbuminemia already on treatment for HE were included. Patients on regular IV albumin infusions were excluded. Participants were randomized 1:1 to receive either weekly infusions of 25% IV albumin 1.5 g/kg or saline over 5 weeks. MHE was defined using either psychometric hepatic encephalopathy score (PHES), Stroop or critical clicker frequency. MHE, QoL (based on sickness impact profile [SIP] total, physical, psychosocial domain) and serum markers (inflammation, endothelial dysfunction, and ischemia-modified albumin) were compared between baseline, the final infusion visit (end-of-drug [EOD]) and 1-week post final infusion (end-of-study [EOS]).

RESULTS

Forty-eight (24/group) participants were randomized and balanced (including by HE medication use) at baseline. Adverse events were similar, with MELD and ammonia remaining stable between/within groups. Albumin levels increased and ischemia-modified albumin decreased only in the albumin group at EOD and EOS vs. baseline. PHES and Stroop MHE reversal and improvement were greater in the albumin group at EOD and persisted at EOS. SIP total and psychosocial, but not physical, domain improved only in the albumin group at EOD and EOS vs. baseline. A significant reduction in IL-1β and endothelial dysfunction markers was also observed in the albumin group.

CONCLUSION

In a double-blind, placebo-controlled trial of outpatients with cirrhosis, prior HE and current MHE, albumin infusions were associated with improved cognitive function and psychosocial QoL, likely due to amelioration of endothelial dysfunction.

CLINICAL TRIALS REGISTRATION

www.

CLINICALTRIALS

gov NCT03585257.

IMPACT AND IMPLICATIONS

Even after recovery from overt hepatic encephalopathy (HE), minimal HE (MHE), which impairs quality of life, can persist. We found that intravenous albumin infusions were associated with improved cognitive function and psychosocial quality of life, likely owing to amelioration of endothelial dysfunction, compared to placebo in outpatients with prior HE and current MHE. In patients who continue to demonstrate cognitive dysfunction and impaired quality of life despite standard of care therapy for HE, albumin infusions could be considered if these results are validated.

Beyond Varices: Complications of Cirrhotic Portal Hypertension in Pediatrics

Complications of cirrhotic portal hypertension (PHTN) in children are broad and include clinical manifestations ranging from variceal hemorrhage, hepatic encephalopathy (HE), ascites, spontaneous bacterial peritonitis (SBP), and hepatorenal syndrome (HRS) to less common conditions such as hepatopulmonary syndrome, portopulmonary hypertension, and cirrhotic cardiomyopathy. The approaches to the diagnosis and management of these complications have become standard of practice in adults with cirrhosis with many guidance statements available. However, there is limited literature on the diagnosis and management of these complications of PHTN in children with much of the current guidance available focused on variceal hemorrhage. The aim of this review is to summarize the current literature in adults who experience these complications of cirrhotic PHTN beyond variceal hemorrhage and present the available literature in children, with a focus on diagnosis, management, and liver transplant decision making in children with cirrhosis who develop ascites, SBP, HRS, HE, and cardiopulmonary complications.

Beta-blockers in patients with liver cirrhosis: Pragmatism or perfection?

With increasing decompensation, hyperdynamic circulatory disturbance occurs in liver cirrhosis despite activation of vasoconstrictors. Here, the concept of a therapy with non-selective beta-blockers was established decades ago. They lower elevated portal pressure, protect against variceal hemorrhage, and may also have pleiotropic immunomodulatory effects. Recently, the beneficial effect of carvedilol, which blocks alpha and beta receptors, has been highlighted. Carvedilol leads to "biased-signaling" via recruitment of beta-arrestin. This effect and its consequences have not been sufficiently investigated in patients with liver cirrhosis. Also, a number of questions remain open regarding the expression of beta-receptors and its intracellular signaling and the respective consequences in the intra- and extrahepatic tissue compartments. Despite the undisputed role of non-selective beta-blockers in the treatment of liver cirrhosis, we still can improve the knowledge as to when and how beta-blockers should be used in which patients.

Longitudinal multi-omics analyses of the gut-liver axis reveals metabolic dysregulation in hepatitis C infection and cirrhosis

The gut and liver are connected via the portal vein, and this relationship, which includes the gut microbiome, is described as the gut-liver axis. Hepatitis C virus (HCV) can infect the liver and cause fibrosis with chronic infection. HCV has been associated with an altered gut microbiome; however, how these changes impact metabolism across the gut-liver axis and how this varies with disease severity and time is unclear. Here we used multi-omics analysis of portal and peripheral blood, faeces and liver tissue to characterize the gut-liver axis of patients with HCV across a fibrosis severity gradient before (n = 29) and 6 months after (n = 23) sustained virologic response, that is, no detection of the virus. Fatty acids were the major metabolites perturbed across the liver, portal vein and gut microbiome in HCV, especially in patients with cirrhosis. Decreased fatty acid degradation by hepatic peroxisomes and mitochondria was coupled with increased free fatty acid (FFA) influx to the liver via the portal vein. Metatranscriptomics indicated that Anaerostipes hadrus-mediated fatty acid synthesis influences portal FFAs. Both microbial fatty acid synthesis and portal FFAs were associated with enhanced hepatic fibrosis. Bacteroides vulgatus-mediated intestinal glycan breakdown was linked to portal glycan products, which in turn correlated with enhanced portal inflammation in HCV. Paired comparison of patient samples at both timepoints showed that hepatic metabolism, especially in peroxisomes, is persistently dysregulated in cirrhosis independently of the virus. Sustained virologic response was associated with a potential beneficial role for Methanobrevibacter smithii, which correlated with liver disease severity markers. These results develop our understanding of the gut-liver axis in HCV and non-HCV liver disease aetiologies and provide a foundation for future therapies.

Association of serum metabolites and gut microbiota at hospital admission with nosocomial infection development in patients with cirrhosis

Cirrhosis is complicated by a high rate of nosocomial infections (NIs), which result in poor outcomes and are challenging to predict using clinical variables alone. Our aim was to determine predictors of NI using admission serum metabolomics and gut microbiota in inpatients with cirrhosis. In this multicenter inpatient cirrhosis study, serum was collected on admission for liquid chromatography-mass spectrometry metabolomics, and a subset provided stool for 16SrRNA analysis. Hospital course, including NI development and death, were analyzed. Metabolomic analysis using analysis of covariance (ANCOVA) (demographics, Model for End-Stage Liver Disease [MELD] admission score, white blood count [WBC], rifaximin, and infection status adjusted) and random forest analyses for NI development were performed. Additional values of serum metabolites over clinical variables toward NI were evaluated using logistic regression. Stool microbiota and metabolomic correlations were compared in patients with and without NI development. A total of 602 patients (231 infection admissions) were included; 101 (17%) developed NIs, which resulted in worse inpatient outcomes, including intensive care unit transfer, organ failure, and death. A total of 127 patients also gave stool samples, and 20 of these patients developed NIs. The most common NIs were spontaneous bacterial peritonitis followed by urinary tract infection, Clostridioides difficile, and pneumonia. A total of 247 metabolites were significantly altered on ANCOVA. Higher MELD scores (odds ratio, 1.05; p < 0.0001), admission infection (odds ratio, 3.54; p < 0.0001), and admission WBC (odds ratio, 1.05; p = 0.04) predicted NI (area under the curve, 0.74), which increased to 0.77 (p = 0.05) with lower 1-linolenoyl-glycerolphosphocholine (GPC) and 1-stearoyl-GPC and higher N-acetyltryptophan and N-acetyl isoputreanine. Commensal microbiota were lower and pathobionts were higher in those who developed NIs. Microbial-metabolite correlation networks were complex and dense in patients with NIs, especially sub-networks centered on Ruminococcaceae and Pseudomonadaceae. NIs are common and associated with poor outcomes in cirrhosis. Admission gut microbiota in patients with NIs showed higher pathobionts and lower commensal microbiota. Microbial-metabolomic correlations were more complex, dense, and homogeneous among those who developed NIs, indicating greater linkage strength. Serum metabolites and gut microbiota on admission are associated with NI development in cirrhosis.

Impact of bacterial infections and spontaneous bacterial peritonitis prophylaxis on phage-bacterial dynamics in cirrhosis

BACKGROUND AND AIMS

Gut microbiota, including bacteria and phages, are altered in cirrhosis, but their role during infections and spontaneous bacterial peritonitis (SBP) prophylaxis is unclear. Our aim was determine metagenomic changes in gut bacteria; phages and their linkages centered around Gram-negative and Gram-positive pathobionts in patients with cirrhosis with/without infections or SBP prophylaxis.

APPROACH AND RESULTS

We included uninfected (n = 231) and infected (n = 30, SBP n = 19 and urinary tract infection n = 11 before antibiotics) patients who gave stool for bacterial and phage metagenomics. We matched uninfected to infected patients 1:1 on a model for end-stage liver disease (MELD). We also analyzed subgroups of patients with ascites matched on an MELD (n = 73) to patients on SBP prophylaxis (n = 7) and then to SBP infection. Phage and bacterial taxa differences (DESeq2) and correlation networks centered around Escherichia coli and Enterococcus faecium were analyzed. Infections were mostly due to Enterobacteriaceae and Enterococcus spp. On metagenomics, higher fold changes of Enterobacteriaceae members, Enterococcus and Streptococcus spp., and Escherichia phages were seen in infected patients. Correlation networks showed more complex bacteria-phage linkages in infected patients compared with uninfected ones overall and centered around E. coli and E. faecium. SBP prophylaxis induced higher Gram-positive bacteria. In SBP, Enterococcus and Escherichia were higher versus ascites. Correlation networks around E. coli were complex in ascites but sparse with SBP prophylaxis, whereas the reverse was seen with E. faecium. Lytic phages and those associated with antibiotic resistance were correlated with E. faecium.

CONCLUSION

In cirrhosis, there are significant changes in phage-bacterial linkages in infected patients and those on SBP prophylaxis compared to the remaining patients. SBP prophylaxis enriches complexity of E. faecium-centered but induces a collapse in E. coli-centered phage-bacterial correlations.

Role of intestinal flora in primary sclerosing cholangitis and its potential therapeutic value

Primary sclerosing cholangitis (PSC) is an autoimmune disease characterized by chronic cholestasis, a persistent inflammation of the bile ducts that leads to sclerotic occlusion and cholestasis. Gut microbes, consisting of microorganisms colonized in the human gut, play an important role in nutrient intake, metabolic homeostasis, immune regulation, and immune regulation; however, their presence might aid PSC development. Studies have found that gut-liver axis interactions also play an important role in the pathogenesis of PSC. Patients with PSC have considerably reduced intestinal flora diversity and increased abundance of potentially pathogenic bacteria. Dysbiosis of the intestinal flora leads to increased intestinal permeability, homing of intestinal lymphocytes, entry of bacteria and their associated metabolites, such as bile acids, into the liver, stimulation of hepatic immune activation, and promotion of PSC. Currently, PSC effective treatment is lacking. However, a number of studies have recently investigated the targeted modulation of gut microbes for the treatment of various liver diseases (alcoholic liver disease, metabolic fatty liver, cirrhosis, and autoimmune liver disease). In addition, antibiotics, fecal microbiota transplantation, and probiotics have been reported as successful PSC therapies as well as for the treatment of gut dysbiosis, suggesting their effectiveness for PSC treatment. Therefore, this review briefly summarizes the role of intestinal flora in PSC with the aim of providing new insights into PSC treatment.

The Mechanisms of Systemic Inflammatory and Immunosuppressive Acute-on-Chronic Liver Failure and Application Prospect of Single-Cell Sequencing

Acute-on-chronic liver failure (ACLF) is a complex clinical syndrome, and patients often have high short-term mortality. It occurs with intense systemic inflammation, often accompanied by a proinflammatory event (such as infection or alcoholic hepatitis), and is closely related to single or multiple organ failure. Liver inflammation begins when innate immune cells (such as Kupffer cells (KCs)) are activated by binding of pathogen-associated molecular patterns (PAMPs) from pathogenic microorganisms or damage-associated molecular patterns (DAMPs) of host origin to their pattern recognition receptors (PRRs). Activated KCs can secrete inflammatory factors as well as chemokines and recruit bone marrow-derived cells such as neutrophils and monocytes to the liver to enhance the inflammatory process. Bacterial translocation may contribute to ACLF when there are no obvious precipitating events. Immunometabolism plays an important role in the process (including mitochondrial dysfunction, amino acid metabolism, and lipid metabolism). The late stage of ACLF is mainly characterized by immunosuppression. In this process, the dysfunction of monocyte and macrophage is reflected in the downregulation of HLA-DR and upregulation of MER tyrosine kinase (MERTK), which weakens the antigen presentation function and reduces the secretion of inflammatory cytokines. We also describe the specific function of bacterial translocation and the gut-liver axis in the process of ACLF. Finally, we also describe the transcriptomics in HBV-ACLF and the recent progress of single-cell RNA sequencing as well as its potential application in the study of ACLF in the future, in order to gain a deeper understanding of ACLF in terms of single-cell gene expression.