C URRENT OPINION Bile acids as metabolic regulators

Purpose of reviewThis review focuses on the latest understanding of the molecular mechanisms underlying the complexinteractions between intestine and liver bile acid signaling, gut microbiota, and their impact on whole-bodylipid, glucose and energy metabolism.Recent findingsHepatic bile acid synthesis is tightly regulated by the bile acid negative feedback mechanisms. Modulatingthe enterohepatic bile acid signaling greatly impacts the whole-body metabolic homeostasis. Recently, apositive feedback mechanism through intestine farnesoid X receptor (FXR) antagonism has been proposedto link gut microbiota to the regulation of bile acid composition and pool size. Two studies identifiedintestine Diet1 and hepatic SHP-2 as novel regulators of CYP7A1 and bile acid synthesis through the gut–liver FXR–fibroblast growth factor 15/19–FGF receptor four signaling axis. New evidence suggests thatenhancing bile acid signaling in the distal ileum and colon contributes to the metabolic benefits of bile acidsequestrants and bariatric surgery.Summary