Targeting Islets: Metabolic Surgery Is More than a Bariatric Surgery

Metabolic surgery is an effective therapy for diabetic patients with obesity. The main mechanisms underlying the effects of metabolic surgery include food intake restriction and the accompanying reduced daily caloric intake and changes in gut hormones and bile acid. Insulin resistance and impaired beta-cell function contribute to the development of type 2 diabetes. An increasing number of studies have focused on the central role of islet function in type 2 diabetes. In this article, we review the related high-quality literature and summarize the following mechanisms and principles underlying metabolic surgery in the context of islet function protection: (1) reduced glucotoxicity and chronic inflammation help facilitate better beta-cell function and the preservation of beta-cell mass following metabolic surgery; (2) based on the increased levels of GLP-1 and PYY after metabolic surgery, gut hormones appear to play a significant role in improving beta-cell function through the GLP-1R signaling pathways; (3) the bile acid signaling pathway could affect beta-cell function; and (4) the GLP-1R and bile acid signaling pathways could also cause other endocrine cells to contribute to islet function.