Potential Molecular Mechanism of Probiotics in Alcoholic Liver Disease

Alcohol consumption and its abuse are significant prevalent cause for liver diseases and death worldwide. Increased bacterial endotoxin in the portal circulation, the plasma ratio of liver enzymes like alanine aminotransferase (ALT), aspartate aminotransferase (AST) and triglyceride implies the symbiotic relation between the gut and liver plays a key function in alcoholic liver disease (ALD). Consumption of alcohol leads to gut dysbiosis and informalities of the intestinal barrier, hyper gut permeability, oxidative stress, inflammation and adversely affect adipose tissue metabolism, and those are mainly recognized as major factors for progression of alcoholic liver disease. Alteration of gut microbiota is referred to as bacterial overgrowth which leads to the release of bacterial products to change in commercial/pathogenic microbiota equilibrium. Lipopolysaccharide (LPS) derived inflammatory signal renders inflammation in alcoholic liver disease. Increase in concentration of lipopolysaccharide leads to activation of toll-like receptor 4 (TLR4) and alteration in micro RNA (miRNA) expression at the transcription level. Activation of myeloid differentiation factor 88 (MyD88) pathways eventually produces pro inflammatory cytokine activation that is an important mediator of alcoholic liver disease. However, there is no effectual Food and Drug Administration (FDA) approved treatment for any stage of alcoholic liver disease. Thus, the potential therapeutic approach for alcoholic liver disease is restoration and alteration of gut microbiota. With the increasing importance of gut microbiota in the onset and occurrence of a variety of diseases, the potential use of probiotics in ALD is receiving more exploration and clinical attention. Probiotic administration is nontoxic, inexpensive and noninvasive strategy with minimal side effects compared to antibiotic therapy and surgery. Yet, there is no substantial evidence on the efficient molecular mechanism regarding mode of action of probiotics on ALD as therapeutics. This review summarizes the research done on gut liver-axis and potential mechanism of probiotic in alcoholic liver disease.