Recent advances in the mechanisms underlying the beneficial effects of bariatric and metabolic surgery

Abstract Bariatric and metabolic surgery (BMS) is the most effective treatment for obesity, type 2 diabetes (T2D) and comorbidities, including nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). The beneficial effects of BMS are beyond the primary goal of gastric restriction and nutrients malabsorption. Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) are the two most commonly performed procedures of BMS. Both surgeries lead to physiological changes in gastrointestinal tract; subsequently alter bile acids pool and composition, gut microbial activities, gut hormones and circulating exosome; and ultimately contribute to the improved glycemic control, insulin sensitivity, lipid metabolism, energy expenditure, as well as weight loss. The mechanisms underlying the benefits of BMS likely involve the bile acids signaling pathway mediated mainly by nuclear farnesoid X receptor (FXR) and the membrane Takeda G protein-coupled receptor (TGR5), bile acids-gut microbiota interaction, and exosomes. In this review, we focus on recent advances in potential mechanisms and aim to learn novel insights into the molecular mechanisms underlying metabolic disorders.