Do changes in gut hormones following bariatric surgery effect weight outcomes: systematic review

Abstract

Abstract Obesity has become a global public health problem and is associated with some serious major health problems like diabetes, cardiovascular diseases, and even cancer. Bariatric surgery has been considered the most effective intervention in reducing body weight among the obese population. Gut hormones are crucial in modulating satiety, energy disbursement in human body, and hunger, therefore, changes in gut hormones followed by bariatric surgery may have a crucial impact on weight outcomes. This study reviews the effect of different types of bariatric surgery, such as adjustable gastric banding, sleeve gastrectomy, and Roux en Y gastric bypass, on the gastrointestinal mechanism and reduction in gut hormones, such as PYY, ghrelin, pancreatic polypeptide, cholecystokinin, and glucagon-like polypeptide-1. Furthermore, this review will investigate the effects of these changes in gut hormones on weight outcomes. An electronic database search was performed using PubMed, Web of science, MEDLINE, and Google scholar using key words identified via a PICO search strategy. Randomised controlled trials (RCTs), observational studies, cross-sectional studies which were available in English language were selected for the systematic review. Also, the selected studies must have measured weight and gut hormones before and after surgery. In total, five studies were reviewed to understand the effect of changes in gut hormone induced weight loss due to bariatric surgery. In response to different bariatric surgeries, changes in gut hormones, such as glucagon-like peptide-1, PYY, ghrelin and other hormones, were found to be associated with the induction and reduction of weight reduction among the patients following bariatric surgery. Gut hormones play a significant role in weight loss following bariatric surgery, which goes beyond malabsorption of nutrients and caloric reduction by affecting appetite signalling. However, the long-term effect of gut hormone induced weight loss is not clear, which calls for further research to confirm the effect of bariatric surgery on gut hormones and its association with weight loss.