For example, decreased gut microbiota metabolism of tryptophan leads to less aryl hydrocarbon receptor activation and intestinal inflammation exacerbation, Eggerthella lenta worsens colitis through metabolizing steroidal glycosides and driving Th17-dependent autoimmunity (Lamas et al., 2016; Alexander et al., 2022). The gene discussed is AHR; the disease is Autoimmunity.