| Abstract: | Several gastrointestinal operations of bariatric surgery, originally designed to achieve and maintain weight loss, can also induce long-term remission of type 2 diabetes mellitus as well as improve other metabolic conditions including hypertension and dyslipidaemia. Moreover, bariatric surgery is increasingly being explored for the treatment of diabetes in moderately obese and non-obese diabetic patients, with positive results. The differences observed amongst the types of bariatric surgery in better control (i.e. sleeve gastrectomy) versus full remission (i.e. Roux-en-Y gastric bypass) of diabetes postoperatively constitute a significant field of study. How surgical gastrointestinal interventions achieve these changes is of a great interest to research, and is evolving rapidly. Several studies have provided evidence that surgical procedures bypassing parts of the small intestine improve glucose homeostasis through mechanisms beyond reduced food intake and body weight. The two major hypotheses put forth to explain these mechanisms are the ‘foregut’ and the ‘hindgut’ hypothesis, focusing on the changes of the secretion pattern of gastrointestinal hormones and neuroendocrine signals observed after surgical manipulation of the gastrointestinal tract. Research to elucidate such weight-independent anti-diabetes mechanisms should facilitate the design of novel anti-diabetic gastrointestinal manipulations, devices and pharmacotherapeutics for obese and non-obese diabetic patients. |
