Probiotics and Liver Disease: Where Are We Now and Where Are We Going?

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.

The dysfunction in intestinal microorganisms and enzyme activity as significant contributors to diarrhea with kidney-yang deficiency syndrome

Object

To investigate the pathogenesis of diarrhea with kidney-yang deficiency syndrome by examining characteristic changes in intestinal microorganisms, enzyme activities, oxidative stress, and metabolism indices.

Methods

Twenty mice were randomly and equally divided into control group (NC) and model group (NM). Mice in NM group received adenine suspension at a dosage of 50 mg/(kg⋅day) by gavage, 0.4 mL/time, once a day for 14 days, and Folium sennae decoction at a dosage of 10 g/(kg⋅day) by gavage, 0.4 mL/time, once a day for 7 days, starting on 8th day. Mice in NC group were administered an equivalent amount of sterile water by gavage once a day for 7 days, and twice a day from the 8th day. After modeling, assessments encompassed microbial culture, organ index calculation, microbial and enzyme activity detection, malondialdehyde (MDA) content determination, superoxide dismutase (SOD) activity, blood biochemical tests, and observation of kidney tissue pathological changes.

Results

The results showed that in NM group, a reduction in the number of Lactobacillus and Bifidobacteria was noted, accompanied by an increase in the number of bacteria and E. coli. Xylanase activity in the intestinal contents and mucosa, protease activity in the intestinal mucosa, and intestinal mucosa microbial activity were diminished. Conversely, the activities of amylase, sucrase, and lactase increased in intestinal mucosa. Additionally, there was an elevation in the level of MDA. Renal tubular dilatation and inflammatory cell infiltration were observed in the renal interstitium.

Conclusion

These dysfunctions in intestinal microorganisms and enzyme activities suggest potential involvement in diarrhea with kidney-yang deficiency syndrome.

Association between probiotic therapy and the risk of hepatocellular carcinoma in patients with hepatitis B-related cirrhosis

Objective

Probiotics may offer cancer-prevention benefits, based on experimental investigation results. This study aimed to determine the potential association between probiotics and hepatocellular carcinoma (HCC) in patients with hepatitis B-related cirrhosis (HBC) receiving antiviral therapy.

Design

This retrospective study included 1267 patients with HBC treated with entecavir or tenofovir between January 2013 and December 2017. The risk of developing HCC was compared between two cohorts of 449 probiotic users (taking a cumulative defined daily doses [cDDD] of ≥ 28) and 818 non-probiotic users (< 28 cDDD). To eliminate the bias caused by confounding factors, propensity score matching (PSM) was used.

Results

On multivariate regression analysis, probiotic consumption was an independent protective factor for HCC occurrence. After PSM, the incidence of HCC was significantly lower in the probiotic users than that in the nonusers (adjusted hazard ratio [aHR]: 0.70, 95% confidence interval: 0.59-0.83, P < 0.001). The aHRs for probiotics with 28-89, 90-180, and >180 cDDD were 0.58, 0.28, and 0.12, respectively, indicating a dose-response pattern. In 28-89, 90-180, and >180 cDDD, the 3-year cumulative incidence of HCC was 8.7%, 4.7%, and 3.0%, respectively. A multivariate stratified analysis confirmed that the administration of probiotics could help patients.

Conclusion

Adjuvant probiotic therapy may reduce the risk of HCC in patients receiving antiviral medication for HBC. However, further clinical research is required to confirm these findings.

Effect of a Diet Supplemented with Sphingomyelin and Probiotics on Colon Cancer Development in Mice

Previous studies have reported that dietary sphingomyelin could inhibit early stages of colon cancer. Lactic acid-producing bacteria have also been associated with an amelioration of cancer symptoms. However, little is known about the potential beneficial effects of the combined administration of both sphingomyelin and lactic acid-producing bacteria. This article analyzes the effect of a diet supplemented with a combination of the probiotics Lacticaseibacillus casei and Bifidobacterium bifidum (10⁸ CFU/ml) and sphingomyelin (0.05%) on mice with 1,2-dimethylhydrazine (DMH)-induced colon cancer. Thirty-six BALB/c mice were divided into 3 groups: one healthy group (group C) and two groups with DMH-induced cancer, one fed a standard diet (group D) and the other fed a diet supplemented with sphingomyelin and probiotics (DS). The number of aberrant crypt foci, marker of colon cancer development, was lower in the DS. The dietary supplementation with the synbiotic reversed the cancer-induced impairment of galactose uptake in enterocyte brush-border-membrane vesicles. These results confirm the beneficial effects of the synbiotic on the intestinal physiology of colon cancer mice and contribute to the understanding of the possible mechanisms involved.

Alteration of Gut Microbiota and Its Impact on Immune Response in Patients with Chronic HBV Infection: A Review

Chronic hepatitis B virus infection is a source of substantial global health problems, particularly in economically underdeveloped and/or developing countries. It is the primary cause of severe liver disorders such as liver fibrosis, cirrhosis, and hepatocellular carcinoma. The liver is connected by the bile duct to the small intestine that carries bile produced in the liver to the intestine. The liver is the initial organ exposed to materials originating from the gut including dietary compounds, bacteria, and their products. Human intestines harbor a wide diversity of the community of microbes which are collectively termed as gut microbiota. In chronic infection with the hepatitis B virus, microbial alteration of the gut is a source of systemic immune activation. Besides, gut permeability is altered in hepatitis B virus-infected patients with an increased bacterial translocation and endotoxin load in the portal vein that caused toll-like receptor activation in the liver, which facilitates immune-mediated liver injury. Toll-like receptors further triggered the host-wide inflammatory response by inducing signaling cascades such as nuclear factor-kappa B-linked pathways and by accelerating cytokine secretion like tumor necrosis factor-alpha, which evokes chronic inflammation and leads to liver lesion formation, fibrosis progression, and cirrhosis and hepatocellular carcinoma development. In conclusion, changes in intestinal flora play an important role in encouraging the production of chronic infection with the hepatitis B virus. Therefore, careful attention should be given to the maintenance of intestinal microecology of patients which can provide a sound foundation for the treatment of chronic infection with the hepatitis B virus.

Contributing Roles of CYP2E1 and Other Cytochrome P450 Isoforms in Alcohol-Related Tissue Injury and Carcinogenesis

The purpose of this review is to briefly summarize the roles of alcohol (ethanol) and related compounds in promoting cancer and inflammatory injury in many tissues. Long-term chronic heavy alcohol exposure is known to increase the chances of inflammation, oxidative DNA damage, and cancer development in many organs. The rates of alcohol-mediated organ damage and cancer risks are significantly elevated in the presence of co-morbidity factors such as poor nutrition, unhealthy diets, smoking, infection with bacteria or viruses, and exposure to pro-carcinogens. Chronic ingestion of alcohol and its metabolite acetaldehyde may initiate and/or promote the development of cancer in the liver, oral cavity, esophagus, stomach, gastrointestinal tract, pancreas, prostate, and female breast. In this chapter, we summarize the important roles of ethanol/acetaldehyde in promoting inflammatory injury and carcinogenesis in several tissues. We also review the updated roles of the ethanol-inducible cytochrome P450-2E1 (CYP2E1) and other cytochrome P450 isozymes in the metabolism of various potentially toxic substrates, and consequent toxicities, including carcinogenesis in different tissues. We also briefly describe the potential implications of endogenous ethanol produced by gut bacteria, as frequently observed in the experimental models and patients of nonalcoholic fatty liver disease, in promoting DNA mutation and cancer development in the liver and other tissues, including the gastrointestinal tract.

The good bugs: the use of probiotics in pediatrics

PURPOSE OF REVIEW

There is growing evidence encouraging the use of probiotics in many conditions in children. However, given the wide number of probiotics available and contradictory data in the literature, the health-care provider is often faced with uncertainness about whether or not to use probiotics and which one(s) to choose. We here review current hypotheses regarding the efficacy and safety of probiotics and evaluate the available data on the use of probiotics in most common diseases in children. Considering that probiotics have strain-specific effects, we will focus on individual probiotic strains rather than on probiotics in general.

RECENT FINDINGS

Strain-specific efficacy was clearly demonstrated with Lactobacillus rhamnosus GG and Saccharomyces boulardii I-745 in the treatment of acute infectious diarrhea, Lactobacillus reuteri DSM 17938 in infantile colics, Lactobacillus rhamnosus GG, and VSL#3 in irritable bowel syndrome. In addition, encouraging results are seen for use of probiotics in necrotizing enterocolitis, food allergy, and nonalcoholic fatty liver disease. However, the data available for constipation are to be considered somewhat equivocal.

SUMMARY

The clinical relevance of these findings indicates that healthcare providers need to take strain-specificity and disease specificity of probiotics into consideration when recommending probiotic for their patients.

Targeting gut microbiota in hepatocellular carcinoma: probiotics as a novel therapy

Hepatocellular carcinoma (HCC), the most common primary liver cancer, is one of the dreaded complications of chronic liver disease. Recent experimental and clinical studies have revealed that the alteration of gut-liver axis plays a pivotal role in the onset of chronic liver diseases, including HCC. Altered gut microbiota and endotoxemia are increasingly recognized as critical components in promoting the progression of chronic liver diseases to HCC. Probiotics have been suggested as a novel, safe and cost-effective approach to prevent or treat HCC. Mechanisms by which probiotics exerts their anti-cancer effects include their ability to bind carcinogens, modulation of gut microbiota, improvement of intestinal barrier function, and immunomodulation. This review summarizes the literature findings of the changes in gut microbiota linked to HCC, and discusses the possible therapeutic implications of probiotics for HCC.

Probiotics and gastrointestinal conditions: An overview of evidence from the Cochrane Collaboration

Alterations in the composition of the gut microbiota are associated with a number of gastrointestinal (GI) conditions, including diarrhea, inflammatory bowel diseases (IBD), and liver diseases. Probiotics, live microorganisms that may confer a health benefit to the host when consumed, are commonly used as a therapy for treating these GI conditions by means of modifying the composition or activity of the microbiota. The purpose of this review was to summarize the evidence on probiotics and GI conditions available from Cochrane, a nonprofit organization that produces rigorous and high-quality systematic reviews of health interventions. Findings from this review will help provide more precise guidance for clinical use of probiotics and to identify gaps in probiotic research related to GI conditions.

Anti-Salmonella activity and probiotic trends of Kluyveromyces marxianus S-2-05 and Kluyveromyces lactis S-3-05 isolated from a French cheese, Tomme d'Orchies

Kluyveromyces marxianus S-2-05 and Kluyveromyces lactis S-3-05 were recently isolated from a traditional French cheese, Tomme d'Orchies, and characterized here for their advantages using a different application perspective. First, we established their anti-Salmonella activity and downregulation of the virulence sopD gene of Salmonella enterica subsp. enterica serovar Typhimurium, mainly in the presence of K. marxianus S-2-05. In addition to their antagonism, these non-Saccharomyces yeasts were able to survive under conditions mimicking the gastrointestinal environment and to form biofilms on an abiotic device such as polystyrene. These strains also displayed highly hydrophilic cell wall surfaces properties and capacity for adhesion to intestinal Caco-2 cells, thus enhancing their potential as probiotic strains.

Is it enough to eliminate hepatitis C virus to reverse the damage caused by the infection?

Hepatitis C virus (HCV) infection represents one of the major causes of chronic liver disease, hepatocellular carcinoma and morbidity/mortality worldwide. It is also a major burden to the healthcare systems. A complete elimination of the HCV from the body through treatment is now possible. However, HCV not only alters the hepatic function. Several extra-hepatic manifestations are present in HCV-infected patients, which increase the mortality rate. Liver and gut are closely associated in what is called the “gut-liver axis”. A disrupted gut barrier leads to an increase in bacterial translocation and an activation of the mucosal immune system and secretion of inflammatory mediators that plays a key role in the progression of liver disease towards decompensated cirrhosis in HCV-infected patients. In addition, both qualitative and quantitative changes in the composition of the gut microbiota (GM) and states of chronic inflammation have been observed in patients with cirrhosis. Thus, a successful treatment of HCV infection should be also accompanied by a complete restoration of GM composition in order to avoid activation of the mucosal immune system, persistent inflammation and the development of long-term complications. Evaluation of GM composition after treatment could be of interest as a reliable indicator of the total or partial cure of these patients. However, studies focused on microbiota composition after HCV eradication from the body are lacking, which opens unique opportunities to deeply explore and investigate this exciting field.