WNT3 and neoplasm: This is also in line with the observation that intestines of these conventional mice displayed increased expression of Wnt3, which promotes stem cell proliferation, survival and tumor development, while Wnt3 expression was not elevated upon conventional FMT (Figures 2(b) and 4(f)).34 To obtain a broader reconstitution of the intestinal phenotypes observed in conventional mice, it would be highly relevant to perform FMT experiments with microbiota derived from pet shop mice, as the microbiota composition of these mice is most comparable to that of conventional mice (Figure S1(d)).