The Effects of Gastrointestinal Surgery on Gut Microbiota: Potential Contribution to Improved Insulin Sensitivity

Bariatric surgery induces weight loss and major improvement in insulin-resistance through many mechanisms some of which are weight independent. It is now well acknowledged that gut microbiota is involved in the development of obesity and its related metabolic diseases, at least in mice. However, its causal role in human obesity progression remains to be demonstrated. Few studies now pointed at changes in microbiota composition after bariatric surgery, suggesting links between gut microbiota switch and metabolic improvement observed after surgery. As such new potential mechanisms of actions have been proposed. The aim of this review is to describe microbiota modifications observed after bariatric surgery and its potential relationships with improved insulin resistance. We here list some hypotheses, which will need further demonstration.