The Crosstalk between Gut Microbiota and Bile Acids Promotes the Development of Non-Alcoholic Fatty Liver Disease

Recently the roles of gut microbiota are highly regarded in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). The intestinal bacteria regulate the metabolism of bile acids depending on bile salt hydrolase (BSH), 7-dehydroxylation, hydroxysteroid dehydrogenase (HSDH), or amide conjugation reaction, thus exerting effects on NAFLD development through bile acid receptors such as farnesoid X receptor (FXR), Takeda G-protein-coupled bile acid protein 5 (TGR5), and vitamin D receptor (VDR), which modulate nutrient metabolism and insulin sensitivity via interacting with downstream molecules. Reversely, the composition of gut microbiota is also affected by the level of bile acids in turn. We summarize the mutual regulation between the specific bacteria and bile acids in NAFLD and the latest clinical research based on microbiota and bile acids, which facilitate the development of novel treatment modalities in NAFLD.

Automated summary

In recent years, the role of gut microbiota in the pathogenesis of NAFLD has been increasingly recognized. Intestinal bacteria regulate bile acid metabolism through various reactions, affecting NAFLD development via bile acid receptors such as FXR, TGR5, and VDR. Conversely, the composition of gut microbiota is also influenced by bile acid levels. This review summarizes the mutual regulation between specific bacteria and bile acids in NAFLD, and the latest clinical research based on microbiota and bile acids, which may lead to novel treatment strategies in NAFLD.