2017-P: Gut Microbes after Bariatric Surgery in Humans Improve Glucose Control in Mice without Fat Loss

Bariatric surgery (BS) is the most efficacious treatment against severe obesity and T2D. Among bariatric procedures, biliopancreatic diversion with duodenal switch (BPD-DS) can produce superior metabolic benefits compared with other surgical options. The mechanisms by which BPD-DS improve metabolic health are not well-understood, but there is evidence implicating the gut microbiota (GM) as contributor to changes in adiposity and consequently blood glucose control. We aimed to determine how the GM before and after BPD-DS alter host metabolism. Fecal samples from female patients subjected to BPD-DS were collected before (pre-surgery) and 12 months after surgery (post-surgery) and used to colonize female C57BL6NTac mice housed either in germ-free (GF) or SPF conditions. Oral glucose tolerance (OGT) was assessed in mice 3 and 7 weeks post-colonization. Three weeks after fecal microbiota transplantation (FMT), glucose tolerance was similar in GF mice receiving pre- and post-surgery fecal slurries. However, GF mice had lower glucose during OGT test 7 weeks after FMT derived from BPD-DS post-surgery compared to GF mice receiving pre-surgery fecal slurry. No changes in fat mass accretion were seen between pre- and post-surgery mice. SPF mice colonized with the fecal microbiota pre- and post-surgery showed no difference in glucose tolerance after 3 and 7 weeks of FMT. These data suggest that the GM after BPD-DS is an independent and transmissible contributor to improved host glucose control. Furthermore, while our data show that the mouse model (e.g., SPF vs. GF) dictates the glycemic response to FMT, exposure time (e.g., at least 7 weeks) is a key factor in microbe transmissible changes in glycemia. Disclosure F. Forato Anhê: None. K.P. Foley: None. N.G. Barra: None. B.M. Duggan: None. J.F. Cavallari: None. B.D. Henriksbo: None. P.D. Cani: Board Member; Self; A-Mansia Biotech. Consultant; Self; Biocodex, Pilèje, Valbiotis. Research Support; Self; Tate & Lyle. Stock/Shareholder; Self; A-Mansia Biotech, Enterosys. L. Biertho: None. A. Tchernof: Research Support; Self; Johnson & Johnson Medical Devices Companies, Medtronic, Pfizer Inc. A. Marette: Advisory Panel; Self; Plexus, Valbiotis. Consultant; Self; Danone Nutricia Research. J.D. Schertzer: None. Funding Canadian Institutes of Health Research; Diabetes Canada