Contribution of gut microbiota to nonalcoholic fatty liver disease: Pathways of mechanisms

Background & aims Non-alcoholic fatty liver disease (NAFLD) is a common, multifactorial liver disease with rapidly increasing prevalence. During the past decade, several lines of evidence have suggested that gut microbiota dysbiosis represents a major factor contributing to NAFLD occurrence and its progression. Method We have performed a review of the published data on the relationship between gut microbiota and risk factors for NAFLD and the role that gut–liver axis plays in the pathogenesis of NAFLD. Results Accumulated evidence has indicated that dysfunction of the gut–liver axis, including increased intestinal permeability, small intestinal bacterial overgrowth, microbiota-derived mediators, and intestinal dysbiosis contribute to the progression and development of NAFLD. Conclusions The findings of this review suggest that lifestyle modification and manipulation of gut microbiota can be considered as a therapeutic target for NAFLD management. However, important documents supporting the role of gut microbiota in NAFLD come from animal studies; therefore, information from studies on humans could lead to novel therapeutics for this highly common disorder.