In this issue of EMBO Molecular Medicine, Jalil et al (Jalil et al, 2025) report that increased production of secondary BAs upon administration of the human bacterium Clostridium scindens (C. scindens) improves colonic health in mice with chemically-induced colitis via activation of the membrane bound BA receptor TGR5. The gene discussed is GPBAR1; the disease is colitis.