For example, A. muciniphila remodeled the structure of bile acids by regulating the intestinal FXR-recombinant fibroblast growth factor 15 (FGF15) axis, reduced secondary bile acids (e.g., deoxycholic acid and lithocholic acid) in the cecum and liver, and ameliorated metabolism-associated steatohepatopathies in high-fat diet-induced obesity mouse models (Wu et al., 2023). The gene discussed is NR1H4; the disease is obesity due to melanocortin 4 receptor deficiency.