Gut microbiota: novel therapeutic target for nonalcoholic fatty liver disease

Introduction: Nonalcoholic fatty liver disease (NAFLD) is one of the most common and increasing liver diseases worldwide with a prevalence of 20-33%. NAFLD may progress to fibrosis, compensated cirrhosis, advanced cirrhosis, or hepatocellular carcinoma. Despite the increasing prevalence of NAFLD, definitive medical treatment has not been established, with the exception of lifestyle modification with exercise. Because of the direct connection via portal vein between the intestines and the liver (gut-gut microbiota-liver axis), gut microbiota and associated dysbiosis have been known as regulators in the pathophysiology of NAFLD. Area covered: New therapeutic approaches for modulation of gut microbiota have been proposed and the effectiveness of new therapies including probiotics, prebiotics, synbiotics, bile acid regulation, absorbent, and fecal microbiota transplantation have been demonstrated in recent several studies. This review focuses on the available evidences for new therapies modulating gut microbiota in the management and the prevention of NAFLD. Expert commentary: Gut-gut microbiota-liver axis may play an important role in the etiology of many liver diseases, including NAFLD. It is logical to seek the manipulation of this axis, and further studies are required to understand the underlying precise mechanisms of microbiota-modulation on NAFLD.