AHR and colitis: In a mouse model of colitis, Amuc_1100 exerted beneficial effects by reducing infiltrating macrophages and CD8+ cytotoxic T lymphocytes in the colon, and by enhancing indoleacetic acid (IAA) and indoleacrylic acid (IA) levels in the microbial tryptophan (Trp) metabolic pathway to activate aryl hydrocarbon receptor (AhR) signaling (Wang et al., 2020).