NR1H4 and Hepatic steatosis: Although Gly-MCA administration did not affect FXR signaling in the liver (Supplementary Figure S10a), it clearly diminished the beneficial effects of RYGB microbiota transfer on hepatic steatosis (Fig. 7g–h and Supplementary Figure S10b), without inherently affecting liver morphology (Supplementary Figure S9e, f).