Furthermore, according to a recent study by Wang et al., Enterobacter ludwigii isolated from metronidazole-treated mouse feces could enhance DCs and promote Tregs differentiation through its metabolite choline and its receptor α7 nicotinic acetylcholine receptor (α7nAChR)-mediated upregulation of retinoic acid (RA) and TGF-β, thereby increasing the CD103+ DC/Treg-dependent tolerance response and ultimately reducing the susceptibility of mice to DSS-induced colitis. Here, CHRNA7 is linked to colitis.