Figure 2.

TGR5 deficiency in MMs causes loss of M2 phenotype and delayed intestinal transit. (A) MMs from tgr5-ko mice showed statistically significantly decreased surface expression of M2 markers CD206 compared with tgr5-wt based on the mean fluorescence intensity (MFI) normalized to isotype controls. (B) Bone marrow chimeras were generated by injecting bone marrow from tgr5-ko or tgr5-wt mice into lethally irradiated tgr5-wt mice. Data are combined from 2 independent experiments. (C) Mice transplanted with bone marrow from tgr5-ko mice (KO→WT) showed statistically significantly delayed intestinal transit compared with those transplanted with wild-type bone marrow (WT→WT). Data are representative of 2 independent whole-gut transit time experiments. (D) Proposed model by which age-dependent changes in microbiota cause a shift from conjugated to deconjugated BAs, resulting in a loss of M2 phenotype in MMs and delayed intestinal transit. n ≥ 9 for each group. *P < .05 by t test.