Type 2 diabetes mellitus is becoming increasingly prevalent worldwide, and has become one of the greatest threats to global health.
Bariatric surgery was initially designed to achieve
weight loss, and subsequently was noted to induce improvements or remission of
type 2 diabetes. Currently, these bariatric operations, such as
Roux-en-Y gastric bypass and sleeve
gastrectomy, are the most effective procedures for the treatment of
obesity and
type 2 diabetes mellitus worldwide. However, the specific mechanism mediating the beneficial effects of
metabolic surgery has remained largely unknown. Those mechanical explanations, such as restriction and malabsorption, are challenged by accumulating evidence from human and animal models of these procedures, which points to the weight-independent factors, such as
hormones,
bile acids, gut microbiota, nervous system and other potential underlying mechanisms. A growing body of evidence suggests that gut microbiota are associated with the development of several metabolic disorders, and
bile acids and FXR signaling are important for the metabolic benefits of
bariatric surgery. Given the close relationship between bacteria and
bile acids, it is reasonable to propose that microbiota-
bile acid interactions play a role in the mechanisms underlying the effects of
metabolic surgery.