Lipopolysaccharide and lipopolysaccharide-binding protein levels and their relationship to early metabolic improvement after bariatric surgery

Abstract

Background: Bariatric surgery usually results in metabolic improvements within a few days from intervention, but the underlying mechanism is not completely understood and may vary depending on the bariatric procedure. Lipopolysaccharides (LPS) from gut microbiota have been proposed as a triggering factor for the inflammatory state in obesity. Roux-en-Y Gastric Bypass (RYGB) leads to a LPS decrease in the medium-term. Objective: To analyze LPS and LPS-binding protein (LBP) in normoglycemic (NG) and diabetic morbidly obese patients in the short-term after 2 different bariatric surgery procedures. Setting: University Hospital, Spain. Methods: Fifty morbidly obese patients underwent bariatric surgery: 24 with sleeve gastrectomy (SG) and 26 with biliopancreatic diversion (BPD). Patients were classified according to their glycemic status as NG or prediabetic/diabetic. LPS and LBP levels and biochemical and anthropometric variables were determined before and at days 15 and 90 after surgery Results: A significant LPS reduction was seen only in the prediabetic/diabetic patients at 90 days after SG. LBP levels rose at 15 days after BPD but at 90 days returned to baseline in both NG and prediabetic/diabetic patients. At 90 days after SG, LBP levels significantly decreased compared to baseline in NG and prediabetic/diabetic patients. After multivariate analysis only the change in BMI was independently associated with the change in LBP levels at 90 days. None of the changes in biochemical or anthropometrical variables were significantly associated with the changes in LPS levels at 15 days or 90 days Conclusion: This is the first study showing that the short-term LPS decrease after bariatric surgery depends on the surgical procedure used as well as on the previous glycemic status of the patient, with SG having the greatest short-term effect on LPS and LBP levels. LBP is closely related to anthropometric variables and may be an inflammatory marker in bariatric surgery patients