INS and metabolic syndrome: Similarly, FMT from humans following RYGB also produced improved metabolic outcome compared with METS.12 We thus repeated this study in humans and investigated short-term effects of allogenic FMT using post-RYGB donors (RYGB-D) or metabolic syndrome donors (METS-D) on insulin sensitivity and lipolysis in METS recipients (RYGB-R and METS-R, respectively; figure 1A), and correlated these effects with changes in gut microbiota composition.