IL10 and colitis: Accordingly, FMT has recently been shown to have an immunosuppressive effect in animal colitis models, where intestinal inflammation could be controlled via the induction of interleukin 10 and transforming growth factor beta, cytokines that are critical for the intestinal accumulation of T-regs.20,21 These findings in animal models are supported by our findings in the four treatment-refractory GI-GvHD patients who responded to FMT and showed intestinal microbiota shifts toward butyrate-producing bacterial species, which have been proven to induce T-reg activity in mice.15,30