IMPACT OF BARIATRIC SURGERY ON THE GUT MICROBIOTA OF CHILEAN PATIENTS

Obesity is a serious health problem worldwide, including Chile. Bariatric surgery (BS) is a highly effective treatment for severe obesity, characterized by a marked and sustained weight loss. In addition to reduced caloric intake, certain studies have identified the intestinal microbiota as a contributing factor in weight loss in BS. An increase in Bacteroidetes and Proteobacteria has been observed in patients after BS. Here we compared the effects of three obesity treatments on the metabolic profiles and gut microbiota in Chilean patients. Patients undergoing gastric bypass (GB,N=5), sleeve gastrectomy (SG,N=5) and medical treatment (MT,N=6) were included in this study. Anthropometric parameters and plasma markers were determined at 0 and 6 months, and major phyla of the gut microbiota were quantified by qPCR. GB and SG were more effective in weight loss compared to MT, also improving glucose and lipid metabolism. Bacteroidetes, but not Enterobacteriaceae were increased in patients who underwent GB. The Firmicutes/Bacteroides ratio was increased in SG patients, but decreased in SG. Finally a negative correlation was found between Firmicutes levels and body weight. This study indicates that BS is more effective in weight loss, but GB and SG change the gut microbiota differently.