Effect of probiotic treatment on deranged neutrophil function and cytokine responses in patients with compensated alcoholic cirrhosis

Microbiota in Alcohol-Associated Organ Damage

Alcohol-associated organ damage is a major cause of morbidity and mortality worldwide, with the liver being the primarily affected organ. Emerging evidence highlights the gut microbiota as a key driver in alcohol-associated liver disease. Changes in the microbiota composition, microbial translocation, and a dysregulated immune response culminate in inflammation and tissue injury. Persistent liver injury eventually promotes disease progression from steatohepatitis to fibrosis and cirrhosis. In this review, we provide an overview of microbiota alterations observed in patients with chronic alcohol consumption and explore the mechanisms by which microbiota contributes to alcohol-associated damage across various organ systems. Emphasis is placed on changes in the gut microbiota and its role in alcohol-associated liver disease, the disease condition with the most robust evidence linking microbiota-related changes to organ injury. Additionally, we highlight key areas where further research is needed to address unresolved questions. Finally, we discuss emerging therapeutic strategies targeting the microbiota to treat alcohol use disorders and prevent alcohol-associated liver diseases.

Effects of Probiotics on Liver Diseases: Current In Vitro and In Vivo Studies

Various types of liver or hepatic diseases cause the death of about 2 million people worldwide every year, of which 1 million die from the complications of cirrhosis and another million from hepatocellular carcinoma and viral hepatitis. Currently, the second most common solid organ transplant is the liver, and the current rate represents less than 10% of global transplant requests. Hence, finding new approaches to treat and prevent liver diseases is essential. In liver diseases, the interaction between the liver, gut, and immune system is crucial, and probiotics positively affect the human microbiota. Probiotics are a non-toxic and biosafe alternative to synthetic chemical compounds. Health promotion by lowering cholesterol levels, stimulating host immunity, the natural gut microbiota, and other functions are some of the activities of probiotics, and their metabolites, including bacteriocins, can exert antimicrobial effects against a broad range of pathogenic bacteria. The present review discusses the available data on the results of preclinical and clinical studies on the effects of probiotic administration on different types of liver diseases.

Intestinal Microbes, Metabolites, and Hormones in Alcohol-Associated Liver Disease

Alcohol-associated liver disease (ALD)-encompassing conditions including steatosis, fibrosis, cirrhosis, and hepatocellular carcinoma-refers to hepatic damage arising from excessive or hazardous alcohol consumption, and is now recognized as a significant global health burden. Although the mechanisms underlying ALD remain incompletely understood, several pathways have been substantiated over the last five decades, notably the involvement of intestinal microorganisms and the involvement of the gut-liver axis in alcohol metabolism and ALD pathogenesis. Ethanol intake disrupts the intestinal microbial balance and compromises the gut barrier, resulting in increased permeability to microbial products. The subsequent translocation of microbial metabolites and other antigenic substances to the liver activates hepatic immune responses, thereby contributing to liver injury. In addition, gastrointestinal hormones are also implicated in ALD progression through various mechanisms. Although no therapies for ALD have been approved by the Food and Drug Administration, various therapeutic strategies targeting the intestinal microbiota and gut barrier have been identified. In conclusion, this review discusses the role of the gut-liver axis in alcohol metabolism and ALD pathogenesis and explores the emerging therapeutic strategies.

Management of hepatic encephalopathy following transjugular intrahepatic portosystemic shunts: Current strategies and future directions

Transjugular intrahepatic portosystemic shunts (TIPSs) are generally used for the management of complications of portal hypertension in patients with decompensated cirrhosis. However, hepatic encephalopathy (HE), which impairs neuropsychiatric function and motor control, remains the primary adverse effect of TIPS, limiting its utility. Prompt prevention and treatment of post-TIPS HE are critical, as they are strongly associated with readmission rates and poor quality of life. This review focuses on the main pathophysiological mechanisms underlying post-TIPS HE, explores advanced biomarkers and predictive tools, and discusses current management strategies and future directions to prevent or reverse HE following TIPS. These strategies include preoperative patient assessment, individualized shunt diameter optimization, spontaneous portosystemic shunt embolization during the TIPS procedure, postoperative preventive and therapeutic measures such as nutrition management, medical therapy, fecal microbiota transplantation, and stent reduction.

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

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

Regulatory mechanisms of the probiotic-targeted gut-liver axis for the alleviation of alcohol-related liver disease: a review

Alcohol abuse-triggered alcohol-related liver disease (ALD) has become as a global public health concern that substantially affects the well-being and clinical status of patients. Although modern medicine provides various treatments for ALD, their effectiveness is limited and can lead to adverse side effects. Probiotics have been employed to prevent, alleviate, and even treat ALD, with promising results. However, few comprehensive reviews are available on how they mitigate ALD by targeting the gut-liver axis. This review systematically clarifies the specific mediators of the gut-liver axis in healthy states. It also describes the alterations observed in ALD. Furthermore, this review thoroughly summarizes the underlying mechanisms through which probiotics act on the gut-liver axis to relieve ALD. It also discusses the current status and challenges faced in clinical research applications. Finally, we discuss the challenges and future prospects of using probiotics to treat ALD. This review improves our understanding of ALD and supports the development and application of probiotics that target the gut-liver axis for therapeutic use.

Immunology and treatments of fatty liver disease

Alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) are two major chronic liver diseases worldwide. The triggers for fatty liver can be derived from external sources such as adipose tissue, the gut, personal diet, and genetics, or internal sources, including immune cell responses, lipotoxicity, hepatocyte death, mitochondrial dysfunction, and extracellular vesicles. However, their pathogenesis varies to some extent. This review summarizes various immune mechanisms and therapeutic targets associated with these two types of fatty liver disease. It describes the gut-liver axis and adipose tissue-liver crosstalk, as well as the roles of different immune cells (both innate and adaptive immune cells) in fatty liver disease. Additionally, mitochondrial dysfunction, extracellular vesicles, microRNAs (miRNAs), and gastrointestinal hormones are also related to the pathogenesis of fatty liver. Understanding the pathogenesis of fatty liver and corresponding therapeutic strategies provides a new perspective for developing novel treatments for fatty liver disease.

Gut Microbiota as Emerging Players in the Development of Alcohol-Related Liver Disease

The global incidence and mortality rates of alcohol-related liver disease are on the rise, reflecting a growing health concern worldwide. Alcohol-related liver disease develops due to a complex interplay of multiple reasons, including oxidative stress generated during the metabolism of ethanol, immune response activated by immunogenic substances, and subsequent inflammatory processes. Recent research highlights the gut microbiota's significant role in the progression of alcohol-related liver disease. In patients with alcohol-related liver disease, the relative abundance of pathogenic bacteria, including Enterococcus faecalis, increases and is positively correlated with the level of severity exhibited by alcohol-related liver disease. Supplement probiotics like Lactobacillus, as well as Bifidobacterium, have been found to alleviate alcohol-related liver disease. The gut microbiota is speculated to trigger specific signaling pathways, influence metabolite profiles, and modulate immune responses in the gut and liver. This research aimed to investigate the role of gut microorganisms in the onset and advancement of alcohol-related liver disease, as well as to uncover the underlying mechanisms by which the gut microbiota may contribute to its development. This review outlines current treatments for reversing gut dysbiosis, including probiotics, fecal microbiota transplantation, and targeted phage therapy. Particularly, targeted therapy will be a vital aspect of future alcohol-related liver disease treatment. It is to be hoped that this article will prove beneficial for the treatment of alcohol-related liver disease.

The gut microbiome in alcohol use disorder and alcohol-associated liver disease: A systematic review of clinical studies

Evidence suggests that a relationship exists between the gut microbiome and the pathogenesis of alcohol use disorder (AUD) and alcohol-associated liver disease (AALD). This systematic review identified studies that investigated the gut microbiome in individuals with an AUD or an AALD. A search was conducted on October 27, 2022, in PubMed, Web of Science, and Embase databases. Fifty studies satisfied eligibility criteria. Most studies found evidence for gut dysbiosis in individuals with AUD and AALD. Microbiome intervention studies have mostly been conducted in AALD patients; fecal microbial transplant interventions show the most promise. Because most studies were conducted cross-sectionally, the causal relationship between the gut microbiome and alcohol use is unknown. Furthermore, almost all studies have been conducted in predominantly male populations, leaving critical questions regarding sex differences and generalizability of the findings. The study summaries and recommendations provided in this review seek to identify areas for further research and to highlight potential gut microbial interventions for treating AUD and AALD.

Role of the Microbiome and the Gut-Brain Axis in Alcohol Use Disorder: Potential Implication for Treatment Development

The gut microbiota is constituted by trillions of microorganisms colonizing the human intestine. Studies conducted in patients with alcohol use disorder (AUD) have shown altered microbial composition related to bacteria, viruses, and fungi.This review describes the communication pathways between the gut and the brain, including the ones related to the bacterial metabolites, the inflammatory cytokines, and the vagus nerve. We described in more detail the gut-derived metabolites that have been shown to be implicated in AUD or that could potentially be involved in the development of AUD due to their immune and/or neuroactive properties, including tryptophan-derivatives, tyrosine-derivatives, short chain fatty acids.Finally, we discussed the potential beneficial effects of microbiome-based therapies for AUD such as probiotics, prebiotics, postbiotic, and phage therapy.

Probiotics-A Promising Novel Therapeutic Approach in the Management of Chronic Liver Diseases

An increased incidence of liver diseases has been observed in recent years and is associated with gut dysbiosis, which causes bacterial infection, intestinal permeability, and further leads to disease-related complications. Probiotics, active microbial strains, are gaining more clinical importance due to their beneficial effect in the management of many diseases, including liver diseases. Clinical scenarios show strong evidence that probiotics have efficacy in treating liver diseases due to their ability to improve epithelial barrier function, prevent bacterial translocation, and boost the immune system. Moreover, probiotics survive both bile and gastric acid to reach the gut and exert their health benefit. Evidence shows that probiotics are a promising approach to prevent several complications in clinical practice. Herein, we discuss the recent evidence, challenges, and appropriate use of probiotics in managing advanced liver diseases, which may have an impact on future therapeutic strategies. Furthermore, the superior effect of strain-specific probiotics and their efficacy and safety in managing liver diseases are discussed.

Effect of Probiotics on Portal Hypertension (PH) with Cirrhosis: A Systematic Review and Meta-Analysis

INTRODUCTION

There are many options for the reduction of portal hypertension (pH) in cirrhotic patients, but all the current ones have side effects. Probiotics are a new approach for ameliorating the hyperdynamic circulation of cirrhotic patients. The aim of this study is to measure the effect of probiotics on pH in cirrhosis for the first time.

METHODS

A search was conducted across four electronic databases (PubMed, Scopus, Web of Science, Cochrane) for English-language records evaluating probiotic effects on pH in cirrhotic patients. Quality assessment used the Cochrane Collaboration's tool, employing a random-effects model in statistical analysis with Stata software version 1.

RESULTS

A search yielded 1,251 articles, which were narrowed down to 5 through screening. These studies, involving 158 participants across Canada, India, Spain, and Russia, focused on probiotic interventions in cirrhotic patients. Meta-analysis of two RCTs (66 participants) indicated a significant decrease in hepatic venous pressure gradient (HVPG) (SMD: -0.60 [-1.09, -0.12]). In single-arm analysis, four studies (58 participants) showed a substantial reduction in HVPG with probiotic use compared to the control (SMD: -2.55 [-3.42, -1.68]).

CONCLUSION

In summary, it showcased a notable reduction in HVPG compared to the control group, indicating a potential advantage of probiotics in decreasing pH in cirrhotic patients. Further research with larger samples and robust designs is warranted.

Microbiota and Gut-Liver Axis: An Unbreakable Bond?

The gut microbiota, amounting to approximately 100 trillion (1014) microbes represents a genetic repertoire that is bigger than the human genome itself. Evidence on bidirectional interplay between human and microbial genes is mounting. Microbiota probably play vital roles in diverse aspects of normal human metabolism, such as digestion, immune modulation, and gut endocrine function, as well as in the genesis and progression of many human diseases. Indeed, the gut microbiota has been most closely linked to various chronic ailments affecting the liver, although concrete scientific data are sparse. In this narrative review, we initially discuss the basic epidemiology of gut microbiota and the factors influencing their initial formation in the gut. Subsequently, we delve into the gut-liver axis and the evidence regarding the link between gut microbiota and the genesis or progression of various liver diseases. Finally, we summarise the recent research on plausible ways to modulate the gut microbiota to alter the natural history of liver disease.

Lactobacillus casei Shirota probiotic drinks reduce antibiotic associated diarrhoea in patients with spinal cord injuries who regularly consume proton pump inhibitors: a subgroup analysis of the ECLISP multicentre RCT

STUDY DESIGN

This was a sub-group analysis of a multicentre, randomised, placebo-controlled, double-blind trial (ECLISP trial) OBJECTIVES: To assess the efficacy of a probiotic containing at least 6.5 × 109 live Lactobacillus casei Shirota (LcS) in preventing antibiotic associated diarrhoea (AAD) in patients with spinal cord injury (SCI) who consumed proton pump inhibitor (PPI) regularly. LcS or placebo was given once daily for the duration of an antibiotic course and continued for 7 days thereafter. The trial was registered with ISRCTN:13119162.

SETTING

Three SCI centres (National Spinal Injuries Centre, Midland Centre for Spinal Injuries and Princess Royal Spinal Cord Injuries Centre) in the United Kingdom METHODS: Between November 2014, and November 2019, 95 eligible consenting SCI patients (median age: 57; IQ range: 43-69) were randomly allocated to receive LcS (n = 50) or placebo (n = 45). The primary outcome is the occurrence of AAD up to 30 days after finishing LcS/placebo.

RESULTS

The LcS group had a significantly lower incidence of AAD at 30 days after finishing the antibiotic course (28.0 v 53.3%, RR: 95% CI: 0.53, 0.31-0.89; z = 2.5, p = 0.01). Multivariate logistic regression analysis identified that LcS can reduce the risk of AAD at 30 days (OR: 0.36, 95% CI 0.13, 0.99, p < 0.05). No intervention-related adverse events were reported during the study.

CONCLUSIONS

LcS has the potential to prevent AAD in what could be considered a defined vulnerable group of SCI patients on regular PPI. A confirmatory, randomised, placebo-controlled study is needed to confirm this apparent therapeutic success to translate it into appropriate clinical outcomes.

SPONSORSHIP

Yakult Honsha Co., Ltd.

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.

Metformin switches cell death modes to soothe the apical periodontitis via ZBP1

Apical periodontitis (AP) is a disease caused by pathogenic microorganisms and featured with the degradation of periapical hard tissue. Our recent research showed the crucial role of Z-DNA binding protein 1 (ZBP1)-mediated necroptosis and apoptosis in the pathogenesis of AP. However, the specific regulatory mechanisms of ZBP1 in AP are not fully elucidated. It was found that metformin has a regulatory role in cell necroptosis and apoptosis. But whether and how metformin regulates necroptosis and apoptosis through the ZBP1 in the context of AP remains unknown. This study provided evidence that lipopolysaccharide (LPS) promotes the synthesis of left-handed Z-nucleic acids (Z-NA), which in turn activates ZBP1. Knockout of Zbp1 by CRISPR/Cas9 technology significantly reduced LPS-induced necroptosis and apoptosis in vitro. By using Zbp1-knockout mice, periapical bone destruction was alleviated. Moreover, type I interferon induced the expression of interferon-stimulated genes (ISGs), which serve as a major source of Z-NA. In addition, the RNA-editing enzyme Adenosine Deaminase RNA specific 1 (ADAR1) prevented the accumulation of endogenous Z-NA. Meanwhile, metformin suppressed the ZBP1-mediated necroptosis by inhibiting the expression of ZBP1 and the accumulation of ISGs. Metformin also promoted mitochondrial apoptosis, which is critical for the elimination of intracellular bacterial infection. The enhanced apoptosis further promoted the healing of infected apical bone tissues. In summary, these results demonstrated that the recognition of Z-NA by ZBP1 plays an important role in AP pathogenesis. Metformin suppressed ZBP1-mediated necroptosis and promoted apoptosis, thereby contributing to the soothing of inflammation and bone healing in AP.

Clinical efficacy of probiotics in the treatment of alcoholic liver disease: a systematic review and meta-analysis

Objective

Alcoholic liver disease (ALD) is a liver damage disease caused by long-term heavy drinking. Currently, there is no targeted pharmaceutical intervention available for the treatment of this disease. To address this, this paper evaluates the efficacy and safety of probiotic preparation in treating ALD through conducting a meta-analysis, and provides a valuable insight for clinical decision-making.

Methods

A systematic search was conducted across databases, including PubMed, Embase, Web of Science, Cochrane Library, CNKI, VIP, Wanfang, and CBM from the inception dates to October 15, 2023, to identify clinical randomized controlled trials on probiotic preparations in the treatment of ALD. After the literature underwent screening, data extraction, and quality assessment, RevMan 5.3 and Stata 14.2 were employed for data analysis and processing.

Results

A total of 9 randomized controlled trials fulfilled the inclusion criteria. The results of the meta-analysis showed that probiotic preparation could significantly improve the liver function of patients with alcoholic liver disease compared with the control group. Probiotic intervention led to a significant reduction in the levels of alanine aminotransferase (MD=-13.36,95%CI:-15.80,-10.91;P<0.00001),aspartate aminotransferase (MD=-16.99,95%CI:-20.38,-13.59;P<0.00001),γ-glutamyl transpeptidase (MD=-18.79,95% CI:-28.23,-9.34; P<0.0001). Concurrently, the level of serum albumin (MD=0.19,95% CI:0.02,0.36;P=0.03) was increased. Furthermore, probiotic intervention could also modulate the composition of intestinal flora in patients with alcoholic liver disease, leading to an augmentation in Bifidobacteria and a reduction in Escherichia coli. However, in patients with alcoholic liver disease, probiotic intervention showed no significant effects on total bilirubin (MD=-0.01,95% CI:-0.17,0.15;P=0.91), tumor necrosis factor-α (MD=0.03,95% CI:-0.86,0.92;P=0.94) and interleukin-6 (MD=-5.3,95% CI:-16.04,5.45;P=0.33).

Conclusion

The meta-analysis indicates that probiotics can improve liver function in alcoholic liver disease, reduce inflammatory responses, regulate intestinal flora, which have potential value in the treatment of alcoholic liver disease.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023472527.

Immune biomarkers in non-treatment-seeking heavy drinkers who used a probiotic supplement for 30 days: An open-label pilot study

Alcohol use disorder (AUD) is associated with significant psychological and economic burdens, as well as physical comorbidities that can lead to death. Previous research has found that probiotics may reduce inflammatory biomarkers in persons with AUD and comorbid conditions such as cirrhosis of the liver. This relationship has not been explored in heavy drinkers without comorbid conditions. In a proof-of-concept study, individuals who were heavy drinkers without known comorbidities received a 30-day course of a daily probiotic supplement in an open-label pilot trial. Eligible participants (N = 16) met NIAAA guidelines for heavy alcohol use and did not report any preexisting medical problems. Blood samples were taken at four timepoints: prior to the probiotic course, at the midpoint, at the end, and after a washout period of at least one month. Immunoassays were conducted on plasma samples to quantify the following inflammatory biomarkers: IL-6, IL-8, IL-10, LBP, MCP-1, sCD14, sCD163, and TNF-α. Linear mixed models were used to test within-subjects changes in biomarker concentrations over the study period, with alcohol use included as a time-varying covariate. Biomarker concentrations did not change significantly. A higher number of heavy drinking days was statistically associated with higher concentrations of IL-6 (F(1,8) = 6.66, p = 0.0326) and IL-8 (F(1,17) = 6.38, p = 0.0218). Greater days since last drink was associated with a lower concentration of MCP-1 (F(1,17) = 5.77, p = 0.028). In summary, biomarker trajectories were associated with alcohol consumption variables, but not probiotic use, in this open-label pilot study. Randomized controlled trials are needed to evaluate fully the potential benefits of probiotics in heavy drinkers without known comorbidities and under conditions of non-abstinence.

Gut-Liver-Brain Axis and Alcohol Use Disorder: Treatment Potential of Fecal Microbiota Transplantation

PURPOSE

Chronic alcohol use is a major cause of liver damage and death. In the United States, multiple factors have led to low utilization of pharmacotherapy for alcohol use disorder (AUD), including lack of provider knowledge and comfort in prescribing medications for AUD. Alcohol consumption has direct effects on the gut microbiota, altering the diversity of bacteria and leading to bacterial overgrowth. Growing evidence suggests that alcohol's effects on the gut microbiome may contribute to increased alcohol consumption and progression of alcohol-associated liver disease (ALD). This article reviews human and preclinical studies investigating the role of fecal microbiota transplantation (FMT) in ameliorating alcohol-associated alterations to the liver, gut, and brain resulting in altered behavior; it also discusses the therapeutic potential of FMT.

SEARCH METHODS

For this narrative review, a literature search was conducted in September 2022 of PubMed, Web of Science Core Collection, and Google Scholar to identify studies published between January 2012 and September 2022. Search terms used included "fecal microbiota transplantation" and "alcohol."

SEARCH RESULTS

Most results of the literature search were review articles or articles on nonalcoholic fatty liver disease; these were excluded. Of the remaining empirical manuscripts, very few described clinical or preclinical studies that were directly investigating the effects of FMT on alcohol drinking or related behaviors. Ultimately, 16 studies were included in the review.

DISCUSSION AND CONCLUSIONS

The literature search identified only a few studies that were directly investigating the effect of FMT on ALD or alcohol drinking and related behaviors. Largely proof-of-concept studies, these findings demonstrate that alcohol can alter the gut microbiome and that the microbiome can be transferred between humans and rodents to alter affective behaviors frequently associated with increased alcohol use. Other studies have shown promise of FMT or other probiotic supplementation in alleviating some of the symptoms associated with ALD and drinking. These results show that the implementation of FMT as a therapeutic approach is still in the investigatory stages.

Pan C, Xing H. Intestinal microbiome-targeted therapies improve liver function in alcohol-related liver disease by restoring bifidobacteria: a systematic review and meta-analysis

Objective: To systematically evaluate the efficacy of intestinal microbiome-targeted therapies (MTTs) in alcohol-related liver disease (ALD). Methods: With pre-specified keywords and strategies, we searched databases including Cochrane Library, PubMed, EMBASE, CNKI, Wanfang Data, and Weipu for RCTs on intestinal MTTs in ALD patients from January 2000 to May 2021. Two researchers independently conducted literature screening, data extraction, and quality evaluation according to the eligible criteria. Outcomes of interest included the effects of intestinal MTTs on ALT, AST, GGT, TBIL, TNF-α, IL-6, intestinal Escherichia coli, and Bifidobacteria when compared to the control group. Pooled data were compiled and analyzed with Revman 5.4 software. Results: Among 5 RCTs included with 456 ALD patients who received probiotics, the therapeutic pooled effects in the experimental group were the followings: ALT (MD = -7.16.95% CI: 10.71∼-3.60; p < 0.0001)、AST (MD = -25.11.95% CI: 30.57∼-19.47; p < 0.00001)、GGT (MD = -6.72.95% CI: 11.91∼-1.53; p = 0.01)、IL-6(SMD = -0.82.95% CI: 1.10∼-0.54; p < 0.00001), which were significantly better than those in the placebo or standard treatment group respectively, while the difference of TBIL (SMD = -0.06, 95%CI: 0.29-0.16; p = 0.59), TNF-α(SMD = -0.53.95% CI: 1.57-0.50; p = 0.31)in the two groups was not significant. After intestinal MTT treatment, the number of intestinal Bifidobacteria increased significantly (MD = 0.79.95% CI: 0.00-1.58; p = 0.05)in the experimental group. However, there were no significant changes in the number of E. coli in both groups (SMD = -0.29.95% CI: 0.92-0.34; p = 0.36). Conclusion: Intestinal MTTs can significantly improve liver function, associated with the increase of intestinal Bifidobacteria, which may be beneficial to ALD. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021246067, Identifier CRD42021246067.

Kefir Ameliorates Alcohol-Induced Liver Injury Through Modulating Gut Microbiota and Fecal Bile Acid Profile in Mice

SCOPE

Alcoholic liver disease (ALD) is the leading cause of liver-related deaths worldwide. Kefir has been studied for its properties of anti-obesity, rebuilding intestinal homeostasis, and alleviating non-alcoholic fatty liver disease. However, the possible role of kefir in the prevention or treatment of ALD has not been carefully considered. Here, it evaluated the protective effects of kefir supplementation on alcohol-induced liver injury.

METHODS AND RESULTS

C57BL/6J mice are fed to Lieber-DeCarli liquid diet containing alcohol to build ALD mouse model, followed by oral administration with kefir. Results indicate that kefir treatment improves liver pathological changes, decreases the expression levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and inflammatory markers, and increases antioxidant levels. Kefir supplementation also restores the intestinal barrier and altered microbial composition, indicates as increases of Blautia, Bacteroides, and Parasutterella and decreases in the Firmicutes/Bacteroidetes (F/B) ratio and populations of Psychrobacter, Bacillus, and Monoglobus. Moreover, kefir supplementation decreases the levels of total bile acids (BAs) and primary BAs and increases the secondary/primary BA ratio. Gut microbes play a key role in the conversion of primary to secondary fecal BAs.

CONCLUSION

Kefir can ameliorate ALD through regulating the composition of the gut microbiota.

Gut liver brain axis in diseases: the implications for therapeutic interventions

Gut-liver-brain axis is a three-way highway of information interaction system among the gastrointestinal tract, liver, and nervous systems. In the past few decades, breakthrough progress has been made in the gut liver brain axis, mainly through understanding its formation mechanism and increasing treatment strategies. In this review, we discuss various complex networks including barrier permeability, gut hormones, gut microbial metabolites, vagus nerve, neurotransmitters, immunity, brain toxic metabolites, β-amyloid (Aβ) metabolism, and epigenetic regulation in the gut-liver-brain axis. Some therapies containing antibiotics, probiotics, prebiotics, synbiotics, fecal microbiota transplantation (FMT), polyphenols, low FODMAP diet and nanotechnology application regulate the gut liver brain axis. Besides, some special treatments targeting gut-liver axis include farnesoid X receptor (FXR) agonists, takeda G protein-coupled receptor 5 (TGR5) agonists, glucagon-like peptide-1 (GLP-1) receptor antagonists and fibroblast growth factor 19 (FGF19) analogs. Targeting gut-brain axis embraces cognitive behavioral therapy (CBT), antidepressants and tryptophan metabolism-related therapies. Targeting liver-brain axis contains epigenetic regulation and Aβ metabolism-related therapies. In the future, a better understanding of gut-liver-brain axis interactions will promote the development of novel preventative strategies and the discovery of precise therapeutic targets in multiple diseases.

Molecular mechanisms of alcohol's effects on the human body: A review and update

Alcohol consumption has been linked to numerous negative health outcomes although it has some beneficial effects on moderate dosages, the most severe of which being alcohol-induced hepatitis. The number of people dying from this liver illness has been shown to climb steadily over time, and its prevalence has been increasing. Researchers have found that alcohol consumption primarily affects the brain, leading to a wide range of neurological and psychological diseases. High-alcohol-consumption addicts not only experienced seizures, but also ataxia, aggression, social anxiety, and variceal hemorrhage that ultimately resulted in death, ascites, and schizophrenia. Drugs treating this liver condition are limited and can cause serious side effects like depression. Serine-threonine kinases, cAMP protein kinases, protein kinase C, ERK, RACK 1, Homer 2, and more have all been observed to have their signaling pathways disrupted by alcohol, and alcohol has also been linked to epigenetic changes. In addition, alcohol consumption induces dysbiosis by changing the composition of the microbiome found in the gastrointestinal tract. Although more studies are needed, those that have been done suggest that probiotics aid in keeping the various microbiota concentrations stable. It has been argued that reducing one's alcohol intake may seem less harmful because excessive drinking is a lifestyle disorder.

Circulating neutrophil anti-pathogen dysfunction in cirrhosis

Neutrophils are the largest population of leucocytes and are among the first cells of the innate immune system to fight against intruding pathogens. In patients with cirrhosis, neutrophils exhibit altered functionality, including changes in phagocytic ability, bacterial killing, chemotaxis, degranulation, reactive oxygen species production and NET (neutrophil extracellular trap) formation. This results in their inability to mount an adequate antibacterial response and protect the individual from infection. Prognosis and survival in patients with cirrhosis are greatly influenced by the development of infectious complications. Multidrug-resistant bacterial infections in patients with cirrhosis are currently a growing problem worldwide; therefore, alternative methods for the prevention and treatment of bacterial infections in cirrhosis are urgently needed. The prevention and treatment of neutrophil dysfunction could be a potential way to protect patients from bacterial infections. However, the reasons for changes in neutrophil function in cirrhosis are still not completely understood, which limits the development of efficient therapeutic strategies. Both cellular and serum factors have been proposed to contribute to the functional impairment of neutrophils. Herein, we review the current knowledge on features and proposed causes of neutrophil dysfunction in cirrhosis, with a focus on current knowledge gaps and limitations, as well as opportunities for future investigations in this field.

Kluyveromyces marxianus supplementation ameliorates alcohol-induced liver injury associated with the modulation of gut microbiota in mice

The aim of this study was to evaluate the intervention effect of the potential probiotic Kluyveromyces marxianus YG-4 isolated from Tibetan kefir grains on alcoholic liver disease (ALD). Eight-week-old male C57BL/6J mice were fed with a Lieber-DeCarli (LDC) diet containing ethanol with a progressively increasing concentration from 1% to 4% (vol/vol) to establish an ALD mouse model. Our results suggested that K. marxianus treatment improved ALD, as demonstrated by the reduction of serum ALT and AST levels and the suppression of TLR4/NF-κB-mediated inflammatory response in the liver. K. marxianus administration significantly elevated antioxidant activities of SOD, CAT and GSH-Px, and reduced the MDA level in mice. K. marxianus supplementation repaired the gut barrier by increasing tight junction proteins and the number of goblet cells in the colon of ALD mice. In addition, treatment with K. marxianus restored alcohol-induced gut dysbiosis. Specifically, K. marxianus administration depleted the abundance of Lactobacillus, Coriobacteriaceae_UCG-002 and Candida, while increased that of Allobaculum, Dubosiella and Epicoccum in mice. Our findings open new possibilities for K. marxianus application in ALD treatment.

The role of neutrophils in alcohol-related hepatitis

Alcohol-related liver disease is a major cause of liver disease-associated mortality, with inpatient care being a major contributor to its clinical and economic burden. Alcohol-related hepatitis (AH) is an acute inflammatory form of alcohol-related liver disease. Severe AH is associated with high short-term mortality, with infection being a common cause of death. The presence of AH is associated with increased numbers of circulating and hepatic neutrophils. We review the literature on the role of neutrophils in AH. In particular, we explain how neutrophils are recruited to the inflamed liver and how their antimicrobial functions (chemotaxis, phagocytosis, oxidative burst, NETosis) may be altered in AH. We highlight evidence for the existence of 'high-density' and 'low-density' neutrophil subsets. We also describe the potentially beneficial roles of neutrophils in the resolution of injury in AH through their effects on macrophage polarisation and hepatic regeneration. Finally, we discuss how manipulation of neutrophil recruitment/function may be used as a therapeutic strategy in AH. For example, correction of gut dysbiosis in AH could help to prevent excess neutrophil activation, or treatments could aim to enhance miR-223 function in AH. The development of markers that can reliably distinguish neutrophil subsets and of animal models that accurately reproduce human disease will be crucial for facilitating translational research in this important field.

Intestinal Microbiotas and Alcoholic Hepatitis: Pathogenesis and Therapeutic Value

Alcoholic hepatitis (AH) is a rapidly progressing and severe stage of alcoholic liver disease, presenting a grim prognosis. Extensive research has elucidated several underlying mechanisms that contribute to the development of AH, including metabolic alterations, immune stimulation, and intestinal dysbiosis. These pathological changes intricately intertwine during the progression of AH. Notably, recent studies have increasingly highlighted the pivotal role of alterations in the intestinal microbiota in the pathogenesis of AH. Consequently, future investigations should place significant emphasis on exploring the dynamics of intestinal microbiota. In this comprehensive review, we consolidate the primary causes of AH while underscoring the influence of gut microbes. Furthermore, by examining AH treatment strategies, we delineate the potential therapeutic value of interventions targeting the gut microbiota. Given the existing limitations in AH treatment options, we anticipate that this review will contribute to forthcoming research endeavors aimed at advancing AH treatment modalities.

Roles of Gut Microbiota in Alcoholic Liver Disease

Alcoholic liver disease (ALD)-one of the most common liver diseases - involves a wide range of disorders, including asymptomatic hepatic steatosis, alcoholic hepatitis (AH), liver fibrosis, and cirrhosis. Alcohol consumption induces a weakened gut barrier and changes in the composition of the gut microbiota. The presence of CYP2E1 and its elevated levels in the gastrointestinal tract after alcohol exposure lead to elevated levels of ROS and acetaldehyde, inducing inflammation and oxidative damage in the gut. At the same time, the influx of harmful molecules such as the bacterial endotoxin LPS and peptidogly from gut dysbiosis can induce intestinal inflammation and oxidative damage, further compromising the intestinal mucosal barrier. In this process, various oxidative stress-mediated post-translational modifications (PTMs) play an important role in the integrity of the barrier, eg, the presence of acetaldehyde will result in the sustained phosphorylation of several paracellular proteins (occludin and zona occludens-1), which can lead to intestinal leakage. Eventually, persistent oxidative stress, LPS infiltration and hepatocyte damage through the enterohepatic circulation will lead to hepatic stellate cell activation and hepatic fibrosis. In addition, probiotics, prebiotics, synbiotics, fecal microbial transplantation (FMT), bioengineered bacteria, gut-restricted FXR agonists and others are promising therapeutic approaches that can alter gut microbiota composition to improve ALD. In the future, there will be new challenges to study the interactions between the genetics of individuals with ALD and their gut microbiome, to provide personalized interventions targeting the gut-liver axis, and to develop better techniques to measure microbial communities and metabolites in the body.

Gut Microbiome-Centered Therapies for Alcohol-Associated Liver Disease

Globally, liver disease caused by alcohol is becoming more prevalent each year. Misuse of alcohol causes a spectrum of liver diseases, such as liver steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. The cornerstone of treatment is abstinence from alcohol. In spite of this, available treatment for alcohol-associated liver disease (ALD) shows limited effectiveness currently. There are numerous ways in which alcohol disrupts the gut-liver axis, including dysbiosis of the gut microbiome, disruption of mucus and epithelial cell barriers, impaired production of antimicrobial molecules, and dysfunction of the immune system, causing translocation of viable microbes and microbial products to the liver and systemic circulation. Microbial exposure results in not only inflammation and progression of liver disease but also infections in late-stage ALD. This led scientists to focus their therapeutic strategies and targets for ALD on the gut microbiome. Throughout this review, we address the role of gut microbiome-centered therapeutic approaches for ALD focusing predominantly on randomized controlled trials. We will summarize the latest clinical trials using probiotics, antibiotics, and fecal microbial transplants in modulating the gut-liver axis and for improvement of ALD.

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.

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

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

Gut Microbiota and Neuroinflammation in Acute Liver Failure and Chronic Liver Disease

Acute liver failure and chronic liver disease are associated with a wide spectrum of neurological changes, of which the best known is hepatic encephalopathy (HE). Historically, hyperammonemia, causing astrocyte swelling and cerebral oedema, was considered the main etiological factor in the pathogenesis of cerebral dysfunction in patients with acute and/or chronic liver disease. However, recent studies demonstrated a key role of neuroinflammation in the development of neurological complications in this setting. Neuroinflammation is characterized by activation of microglial cells and brain secretion of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6, which alter neurotransmission, leading to cognitive and motor dysfunction. Changes in the gut microbiota resulting from liver disease play a crucial role in the pathogenesis of neuroinflammation. Dysbiosis and altered intestinal permeability, resulting in bacterial translocation and endotoxemia, are responsible for systemic inflammation, which can spread to brain tissue and trigger neuroinflammation. In addition, metabolites derived from the gut microbiota can act on the central nervous system and facilitate the development of neurological complications, exacerbating clinical manifestations. Thus, strategies aimed at modulating the gut microbiota may be effective therapeutic weapons. In this review, we summarize the current knowledge on the role of the gut-liver-brain axis in the pathogenesis of neurological dysfunction associated with liver disease, with a particular focus on neuroinflammation. In addition, we highlight emerging therapeutic approaches targeting the gut microbiota and inflammation in this clinical setting.

Harnessing the potential of probiotics in the treatment of alcoholic liver disorders

In the current scenario, prolonged consumption of alcohol across the globe is upsurging an appreciable number of patients with the risk of alcohol-associated liver diseases. According to the recent report, the gut-liver axis is crucial in the progression of alcohol-induced liver diseases, including steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Despite several factors associated with alcoholic liver diseases, the complexity of the gut microflora and its great interaction with the liver have become a fascinating area for researchers due to the high exposure of the liver to free radicals, bacterial endotoxins, lipopolysaccharides, inflammatory markers, etc. Undoubtedly, alcohol-induced gut microbiota imbalance stimulates dysbiosis, disrupts the intestinal barrier function, and trigger immune as well as inflammatory responses which further aggravate hepatic injury. Since currently available drugs to mitigate liver disorders have significant side effects, hence, probiotics have been widely researched to alleviate alcohol-associated liver diseases and to improve liver health. A broad range of probiotic bacteria like Lactobacillus, Bifidobacteria, Escherichia coli, Sacchromyces, and Lactococcus are used to reduce or halt the progression of alcohol-associated liver diseases. Several underlying mechanisms, including alteration of the gut microbiome, modulation of intestinal barrier function and immune response, reduction in the level of endotoxins, and bacterial translocation, have been implicated through which probiotics can effectively suppress the occurrence of alcohol-induced liver disorders. This review addresses the therapeutic applications of probiotics in the treatment of alcohol-associated liver diseases. Novel insights into the mechanisms by which probiotics prevent alcohol-associated liver diseases have also been elaborated.

Drinking and laboratory biomarkers, and nutritional status characterize the clinical presentation of early-stage alcohol-associated liver disease

Chronic and heavy alcohol consumption is commonly observed in alcohol use disorder (AUD). AUD often leads to alcohol-associated organ injury, including alcohol-associated liver disease (ALD). Approximately 10-20% of patients with AUD progress to ALD. Progression of ALD from the development phase to more advanced states involve the interplay of several pathways, including nutritional alterations. Multiple pathologic processes have been identified in the progression and severity of ALD. However, there are major gaps in the characterization and understanding of the clinical presentation of early-stage ALD as assessed by clinical markers and laboratory measures. Several Institutions and Universities, including the University of Louisville, in collaboration with the National Institutes of Health, have published a series of manuscripts describing early-stage ALD over the past decade. Here, we comprehensively describe early-stage ALD using the liver injury and drinking history markers, and the laboratory biomarkers (with a focus on nutrition status) that are uniquely involved in the development and progression of early-stage ALD.

Effects of Probiotic and Selenium Co-supplementation on Lipid Profile and Glycemia Indices: A Systematic Review and Meta-analysis of Randomized Clinical Trials

PURPOSE OF REVIEW

The current systematic review and meta-analysis was done to evaluate the effects of selenium and probiotic co-supplementation on lipid profile and glycemia indices of the adult population using randomized controlled clinical trials (RCTs).

RECENT FINDINGS

Five studies involving 282 participants with a sample size ranging from 38 to 79 were eligible to be enrolled in the current study. Co-supplementation with probiotic and selenium reduced fasting plasma glucose (WMD =  -4.02 mg/dL; 95% CI: -5.87 to -2.18; P < 0.001), insulin (WMD =  -2.50 mIU/mL; 95% CI: -3.11 to -1.90; P < 0.001), homeostatic model assessment for insulin resistance (WMD =  -0.59; 95% CI: -0.74 to -0.43; P < 0.001), quantitative insulin sensitivity check index (WMD = 0.01; 95% CI: 0.01 to 0.02; P < 0.001), total cholesterol (WMD =  -12.75 mg/dL; 95% CI: -19.44 to -6.07; P < 0.001), low-density lipoprotein cholesterol (WMD =  -7.09 mg/dL; 95% CI: -13.45 to -0.73; P = 0.029), and triglyceride (WMD =  -14.38 mg/dL; 95% CI: -23.13 to -5.62; P = 0.001). The findings of the current systematic review and meta-analysis suggested that co-supplementation with probiotics and selenium may benefit adults in terms of glycemia indices and lipid profile. However, due to the small number of included studies, further trials are needed to confirm our findings.

Emerging Pharmacotherapies in Alcohol-Associated Hepatitis

The incidence of alcoholic-associated hepatitis (AH) is increasing. The treatment options for severe AH (sAH) are scarce and limited to corticosteroid therapy which showed limited mortality benefit in short-term use only. Therefore, there is a dire need for developing safe and effective therapies for patients with sAH and to improve their high mortality rates.This review article focuses on the current novel therapeutics targeting various mechanisms in the pathogenesis of alcohol-related hepatitis. Anti-inflammatory agents such as IL-1 inhibitor, Pan-caspase inhibitor, Apoptosis signal-regulating kinase-1, and CCL2 inhibitors are under investigation. Other group of agents include gut-liver axis modulators, hepatic regeneration, antioxidants, and Epigenic modulators. We describe the ongoing clinical trials of some of the new agents for alcohol-related hepatitis.

CONCLUSION

A combination of therapies was investigated, possibly providing a synergistic effect of drugs with different mechanisms. Multiple clinical trials of novel therapies in AH remain ongoing. Their result could potentially make a difference in the clinical course of the disease. DUR-928 and granulocyte colony-stimulating factor had promising results and further trials are ongoing to evaluate their efficacy in the large patient sample.

Therapeutic targets in alcohol-associated liver disease: progress and challenges

Alcohol-associated liver disease (ALD) is a complex disease with rapidly increasing prevalence. Although there are promising therapeutic targets on the horizon, none of the newer targets is currently close to an Food and Drug Administration approval. Strategies are needed to overcome challenges in study designs and conducting clinical trials and provide impetus to the field of drug development in the landscape of ALD and alcoholic hepatitis. Management of ALD is complex and should include therapies to achieve and maintain alcohol abstinence, preferably delivered by a multidisciplinary team. Although associated with clear mortality benefit in select patients, the use of early liver transplantation still requires refinement to create uniformity in selection protocols across transplant centers. There is also a need for reliable noninvasive biomarkers for prognostication. Last but not the least, strategies are urgently needed to implement integrated multidisciplinary care models for treating the dual pathology of alcohol use disorder and of liver disease for improving the long-term outcomes of patients with ALD.

Microbial treatment of alcoholic liver disease: A systematic review and meta-analysis

Background and aims

Alcoholic liver disease (ALD) is characterized by impaired liver function due to chronic alcohol consumption, even fatal in severe cases. We performed a meta-analysis to determine whether microbial agents have therapeutic potential for ALD and elucidate the underlying mechanisms.

Methods and results

Forty-one studies were eligible for this meta-analysis after searching the PubMed, Cochrane, and Embase databases. The combined analysis showed that microbial therapy significantly decreased hepatic enzymatic parameters, including alanine transaminase [standardized mean difference (SMD): -2.70, 95% confidence interval (CI): -3.33 to -2.07], aspartate aminotransferase (SMD: -3.37, 95% CI: -4.25 to -2.49), γ-glutamyl transpeptidase (SMD: -2.07, 95% CI: -3.01 to -1.12), and alkaline phosphatase (SMD: -2.12, 95% CI: -3.32 to -0.92). Microbial agents endotoxin to enter the portal circulation and increasing reduced total cholesterol (SMD = -2.75, 95%CI -4.03 to -1.46) and triglycerides (SMD = -2.64, 95% CI: -3.22 to -2.06). Microbial agents increased amounts of the beneficial flora Lactobacillus (SMD: 4.40, 95% CI: 0.97-7.84) and Bifidobacteria (SMD: 3.84, 95% CI: 0.22-7.45), Bacteroidetes (SMD: 2.51, 95% CI: 0.29-4.72) and decreased harmful Proteobacteria (SMD: -4.18, 95% CI: -6.60 to -1.77), protecting the integrity of the intestinal epithelium and relieving endotoxin (SMD: -2.70, 95% CI: -3.52 to -2.17) into the portal vein, thereby reducing the production of inflammatory factors such as tumor necrosis factor-α (SMD: -3.35, 95% CI: -4.31 to -2.38), interleukin-6 (SMD: -4.28, 95% CI: -6.13 to -2.43), and interleukin-1β (SMD: -4.28, 95% CI: -6.37 to -2.19). Oxidative stress was also relieved, as evidenced by decreased malondialdehyde levels (SMD: -4.70, 95% CI: -6.21 to -3.20). Superoxide dismutase (SMD: 2.65, 95% CI: 2.16-3.15) and glutathione levels (SMD: 3.80, 95% CI: 0.95-6.66) were elevated.

Conclusion

Microbial agents can reverse dysbiosis in ALD, thus significantly interfering with lipid metabolism, relieving inflammatory response and inhibiting oxidative stress to improve liver function.

Pathogenesis of Alcohol-Associated Liver Disease

Excessive alcohol consumption is a global healthcare problem with enormous social, economic, and clinical consequences. While chronic, heavy alcohol consumption causes structural damage and/or disrupts normal organ function in virtually every tissue of the body, the liver sustains the greatest damage. This is primarily because the liver is the first to see alcohol absorbed from the gastrointestinal tract via the portal circulation and second, because the liver is the principal site of ethanol metabolism. Alcohol-induced damage remains one of the most prevalent disorders of the liver and a leading cause of death or transplantation from liver disease. Despite extensive research on the pathophysiology of this disease, there are still no targeted therapies available. Given the multifactorial mechanisms for alcohol-associated liver disease pathogenesis, it is conceivable that a multitherapeutic regimen is needed to treat different stages in the spectrum of this disease.

Probiotic potential and immunomodulatory properties in Enterococcus faecium GMB24 and Enterococcus hirae SMB16 isolated from goat and sheep milk

Probiotic attributes of lactic acid bacteria isolated from goat and sheep milk samples were analysed by culturing them on an MRS agar medium. The most potential isolates, GMB24 and SMB16, were identified by biochemical tests which had ability to tolerate different concentrations of acid and bile and phenol resistance. They were further identified as Enterococcus faecium GMB24 and Enterococcus hirae SMB16 by 16S rRNA gene sequencing approach. The probiotic potential of the isolates GMB24 and SMB16 were recorded including antimicrobial activity against pathogenic bacteria viz., Escherichia coli (MTCC118), Staphylococcus aureus (MTCC7443), Pseudomonas aeruginosa (MTCC424), Listeria monocytogens (MTCC657) and Salmonella typhimurium (MTCC733), and antibiotic susceptibility test. The isolates SMB16 and GMB24 exhibited a higher zone of inhibition against P. aeruginosa (19.00 ± 0.57 mm) and S. aureus (25.66 ± 0.88 mm), respectively. The data from these experiments were used for the principal component analysis (PCA) to assess the survivability of the isolates under different factors. The heatmap generated in this study clustered the bacterial isolates based on their phenotype properties. Further, immunomodulating activities of these probiotic bacteria were tested on neutrophil adhesion test, haemagglutinating antibody titer and delayed-type hypersensitivity. Probiotic E. faecium GMB24 and E. hirae SMB16, at 10⁹ cells/mL doses per day, increased the neutrophil adhesion, haemagglutinating antibody titer and DTH in comparison to the untreated control group. The isolates showed negative test for haemolytic and gelatinase activities and hence were considered safe. E. faecium GMB24 and E. hirae SMB16 were shown to have high probiotic potential and immune-stimulant action.

The effect of Lactobacillus rhamnosus B10 on alcoholic liver injury and intestinal microbiota in alcohol-induced mice model

Lactobacillus rhamnosus B10 (L. rhamnosus B10) isolated from the baby feces was given to an alcohol mice model, aiming to investigate the effects of L. rhamnosus B10 on alcoholic liver injury by regulating intestinal microbiota. C57BL/6N mice were fed with liquid diet Lieber-DeCarli with or without 5% (v/v) ethanol for 8 weeks, and treated with L. rhamnosus B10 at the last 2 weeks. The results showed that L. rhamnosus B10 decreased the serum total cholesterol (1.48 mmol/L), triglycerides (0.97 mmol/L), alanine aminotransferase (26.4 U/L), aspartate aminotransferase (14.2 U/L), lipopolysaccharide (0.23 EU/mL), and tumor necrosis factor-α (138 pg/mL). In addition, L. rhamnosus B10 also reduced the liver triglycerides (1.02 mmol/g prot), alanine aminotransferase (17.8 mmol/g prot) and aspartate aminotransferase (12.5 mmol/g prot) in alcohol mice, thereby ameliorating alcohol-induced liver injury. The changes of intestinal microbiota composition on class, family and genus level in cecum were analyzed. The intestinal symbiotic abundance of Firmicutes was elevated while gram-negative bacteria Proteobacteria and Deferribacteres was decreased in alcohol mice treated with L. rhamnosus B10 for 2 weeks. In summary, this study provided evidence for the therapeutic effects of probiotics on alcoholic liver injury by regulating intestinal flora.

Gut microbiota-modulating agents in alcoholic liver disease: Links between host metabolism and gut microbiota

Alcoholic liver disease (ALD) involves a wide spectrum of diseases, including asymptomatic hepatic steatosis, alcoholic hepatitis, hepatic fibrosis, and cirrhosis, which leads to morbidity and mortality and is responsible for 0.9% of global deaths. Alcohol consumption induces bacterial translocation and alteration of the gut microbiota composition. These changes in gut microbiota aggravate hepatic inflammation and fibrosis. Alteration of the gut microbiota leads to a weakened gut barrier and changes host immunity and metabolic function, especially related to bile acid metabolism. Modulation and treatment for the gut microbiota in ALD has been studied using probiotics, prebiotics, synbiotics, and fecal microbial transplantation with meaningful results. In this review, we focused on the interaction between alcohol and gut dysbiosis in ALD. Additionally, treatment approaches for gut dysbiosis, such as abstinence, diet, pro-, pre-, and synbiotics, antibiotics, and fecal microbial transplantation, are covered here under ALD. However, further research through human clinical trials is warranted to evaluate the appropriate gut microbiota-modulating agents for each condition related to ALD.

Amelioration of Non-Alcoholic Steatohepatitis by Atractylodes macrocephala Polysaccharide, Chlorogenic Acid, and Geniposide Combination Is Associated With Reducing Endotoxin Gut Leakage

Gut-derived lipopolysaccharide (LPS) leaking through the dysfunctional intestinal barrier contributes to the onset of non-alcoholic steatohepatitis (NASH) by triggering inflammation in the liver. In the present study, a combination consisting of Atractylodes macrocephala polysaccharide (A), chlorogenic acid (C), and geniposide (G) (together, ACG), was shown to ameliorate NASH in mice and reduce hepatic LPS signaling and endotoxemia without decreasing the abundance of identified Gram-negative bacteria through restoring the intestinal tight junctions. Our data indicated that inhibition of LPS gut leakage by the ACG combination contributed to its amelioration of NASH.

Role of gut bacterial and non-bacterial microbiota in alcohol-associated liver disease: Molecular mechanisms, biomarkers, and therapeutic prospective

Alcohol-associated liver disease (ALD) comprises a spectrum of liver diseases that include: steatosis to alcohol-associated hepatitis, cirrhosis, and ultimately hepatocellular carcinoma. The pathophysiology and potential underlying mechanisms for alcohol-associated liver disease are unclear. Moreover, the treatment of ALD remains a challenge. Intestinal microbiota include bacteria, fungi, and viruses, that are now known to be important in the development of ALD. Alcohol consumption can change the gut microbiota and function leading to liver disease. Given the importance of interactions between intestinal microbiota, alcohol, and liver injury, the gut microbiota has emerged as a potential biomarker and therapeutic target. This review focuses on the potential mechanisms by which the gut microbiota may be involved in the pathogenesis of ALD and explains how this can be translated into clinical management. We discuss the potential of utilizing the gut microbiota signature as a biomarker in ALD patients. Additionally, we present an overview of the prospect of modulating the intestinal microbiota for the management of ALD.

Principles of diagnosis and treatment of alcohol-induced liver fibrosis

Alcohol-related liver diseases are one of the leading causes of death worldwide, primarily due to complications of liver cirrhosis (LC). Early detection of alcohol-induced liver fibrosis (LF) is a difficult task, since often  alcoholic liver disease (ALD) is clinically manifested only at late stages. Given that not all alcoholic suffer from ALD, the widespread use of liver biopsy to verify the diagnosis is not advisable. Despite the variety of proposed non-invasive methods for assessing the severity of LF in patients with ALD, none of them has sufficient validation and therefore cannot be recommended for widespread use in clinical practice. The most well-studied transient elastography, due to its suboptimal specificity, can be effectively used only to exclude clinically significant LF or LC. The only proven approach to treat ALD is persistent and total alcohol abstinence. While the therapeutic options for patients with severe forms of acute hepatitis remain unchanged since the 70s of the last century and are based mainly on the use of corticosteroids, currently, there are no approaches to antifibrotic therapy of ALD approved by the guidelines. At the same time, modern achievements in understanding the pathophysiological mechanisms  of this disease  have served  as an impetus  for  the development  of ways to solve  the problem. In particular, providing intestinal eubiosis may be an important goal for the prevention and treatment of alcohol-induced LF. Randomized controlled multicenter trials involving a large number of patients are needed to confirm this and other hypotheses related to antifibrotic therapy of ALD and to accept them as a standard of medical care.

Gut Microbiota Targeted Approach in the Management of Chronic Liver Diseases

The liver is directly connected to the intestines through the portal vein, which enables the gut microbiota and gut-derived products to influence liver health. There is accumulating evidence of decreased gut flora diversity and alcohol sensitivity in patients with various chronic liver diseases, including non-alcoholic/alcoholic liver disease, chronic hepatitis virus infection, primary sclerosing cholangitis and liver cirrhosis. Increased intestinal mucosal permeability and decline in barrier function were also found in these patients. Followed by bacteria translocation and endotoxin uptake, these will lead to systemic inflammation. Specific microbiota and microbiota-derived metabolites are altered in various chronic liver diseases studies, but the complex interaction between the gut microbiota and liver is missing. This review article discussed the bidirectional relationship between the gut and the liver, and explained the mechanisms of how the gut microbiota ecosystem alteration affects the pathogenesis of chronic liver diseases. We presented gut-microbiota targeted interventions that could be the new promising method to manage chronic liver diseases.

Gut Microbiome Dysbiosis in Alcoholism: Consequences for Health and Recovery

Since the mid 1980's, the impact of gastrointestinal (GI) microbiome changes during alcohol use disorder has been an area of significant interest. This work has resulted in the identification of specific changes in the abundance of certain members of the GI microbiome and the role these changes play in a variety of alcohol related disorders (i.e. alcoholic liver disease). Interestingly, some findings suggest a possible role for the GI microbiome in alcohol addiction or withdrawal. Unfortunately, there is a significant gap in knowledge in this area. Here we describe differences in the GI microbiome of alcoholic and non-alcoholic individuals and discuss the possible impact of microbes on the gut-brain axis, which could impact alcohol related behaviors (i.e. addiction). Understanding the role of the GI microbiome in alcohol related disorders will potentially lead to the development of successful microbiome-targeted therapeutics to help mitigate these disorders.