Ménage-à-trois of bariatric surgery, bile acids and the gut microbiome

Core Tip

Core tip: The report of Ryan et al, raises a number of questions with regard to the prevailing notion that mechanical restriction of the stomach and weight loss are the sole mechanisms that mediate the therapeutic effects of bariatric surgery. The authors showed that both lowering of body mass index and improved glucose tolerance after vertical sleeve gastrectomy (VSG) surgery were mechanistically linked to an altered composition of circulating bile acids and their ability to modulate farnesoid-X receptor (FXR) mediated signaling mechanisms. Additionally, it was observed that the wild type and FXR knockout mice, after receiving VSG surgery, were significantly different with respect to the make up of their gut microbiomes. Finally, the experiments revealed that the composition of gut microbiota in wild type VSG and FXR^-/- VSG mice were highly correlated with their differential abilities to lose weight and acquire glucose tolerance.