The Metabolic Effects of Pre-probiotic Supplementation After Roux-en-Y Gastric Bypass (RYGB) Surgery: a Prospective, Randomized Controlled Study

Following Roux-en-Y gastric bypass (RYGB), positive alterations are observed in gut microbiota and intestinal peptides. Previous studies demonstrated similar alterations observed in cases when pre-probiotics are used without surgery. The aim of this trial was to evaluate the effectiveness of early use of pre-probiotics after RYGB. The operation and follow-up of the patients were performed at Istanbul University Medical Faculty. Thirty-two patients who had undergone RYGB were randomized to pre-probiotic group (PreProBG, n = 16; 200 g/day yogurt plus 10 g/day inulin+oligofructose) and probiotic group (ProBG, n = 16; 200 g/day yogurt only) for 6 months. Blood samples (glucose, insulin, A1c, GLP-1, PYY), anthropometric measurements, and appetite ratings have been evaluated at baseline and 3 (m3) and 6 (m6) months after RYGB. Initial anthropometric measurements and appetite ratings decreased significantly after surgery and there were no significant differences between the groups. The decrease of area under the curve(insulin) was less and has a positive correlation with the changes in anthropometric measurements in PreProBG. GLP-1 and PYY which increased dramatically after surgery in all patients were higher in PreProBG. But this increase had a negative correlation with the changes in anthropometric measurements during the study. Increased insulin, GLP-1, and PYY secretion was more enhanced by pre-probiotic use in early postoperative period. But this increase not only in anthropometric measurements but also in appetite ratings affects negatively, contrary to expectations. In summary, it should be investigated with new studies that use of pre-probiotics in the late postoperative period may be more effective in patients with weak insulin and incretin response and therefore insufficient weight loss. Trial Registration clinicaltrials.gov Identifier: NCT03517345.