FMT in Obesity: RYGB vs. LEAN vs. Autologous FMT

This double-blinded proof-of-concept study is proposed to explore the effects of fecal microbiota transfer (FMT) in human subjects. Here we perform FMTs into obese recipients using stool from lean unoperated donors and from previously obese patients after successfull treatment with bariatric Roux-en-Y Gastric Bypass (RYGB) surgery. Obese patients treated with their own material (autologous FMT) serve as controls. After FMT treatment the functional impact of post-surgery microbiome changes on host energy consumption and regulation of blood glucose levels will be analysed. Additionally the variations on the microbiota and metabolite composition will be profiled using extensive sequencing analyses. The major aim of the study is to explore the scientific rationale for targeted gut microbiota modulation in management of obesity and related metabolic diseases.We estimate the transfer of microbiota from RYGB donors is superior to the transfer of lean microbiota at inducing reduced adiposity and improving high blood glucose levels in obese recipients. Each is better than a sham procedure (autologous FMT), which itself can also induce considerable short-term effects.