Published online Feb 14, 2015. doi: 10.3748/wjg.v21.i6.1691
Peer-review started: November 26, 2014
First decision: December 26, 2014
Revised: January 8, 2015
Accepted: January 21, 2015
Article in press: January 21, 2015
Published online: February 14, 2015
Several studies revealed that gut microbiota are associated with various human diseases, e.g., metabolic diseases, allergies, gastroenterological diseases, and liver diseases. The liver can be greatly affected by changes in gut microbiota due to the entry of gut bacteria or their metabolites into the liver through the portal vein, and the liver-gut axis is important to understand the pathophysiology of several liver diseases, especially non-alcoholic fatty liver disease and hepatic encephalopathy. Moreover, gut microbiota play a significant role in the development of alcoholic liver disease and hepatocarcinogenesis. Based on these previous findings, trials using probiotics have been performed for the prevention or treatment of liver diseases. In this review, we summarize the current understanding of the changes in gut microbiota associated with various liver diseases, and we describe the therapeutic trials of probiotics for those diseases.
Core tip: Gut microbiota are associated with various human diseases (e.g., metabolic, gastroenterological and liver diseases, and allergies). Genomic analyses of gut microbiota have enabled the comprehensive identification of the population of gut bacteria and revealed that changes in these populations are involved in various diseases’ pathophysiology. The liver is affected by changes in the intestinal milieu due to the entry of gut bacteria or their metabolites into the liver through the portal vein. Here we summarize the current understanding of changes in gut microbiota associated with various liver diseases. We also summarize the recent therapeutic trials of probiotics in liver diseases.