We thank Cui et al for their comments regarding our randomized controlled trial of fecal microbiota transplantation (FMT) for patients with ulcerative colitis (NCT01650038).1 The authors are concerned by the in their view unexpectedly high placebo response rate of 25% in our trial as opposed to the 5% response rate in the trial by Moayyedi et al,2 which was published in the same issue of Gastroenterology. They suggest that this difference is owing to the choice of placebo (autologous feces vs water enemas), and suspect that the median lag time between production and reinfusion of feces of 6 hours with exposure to aerobic conditions might have influenced the function or viability of certain kinds of microbiota.