Amelioration of colitis through restored gut ecology using Christensenella intestinihominis AF73-05CM02 as a probiotic in mice.

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is closely linked to gut microbial imbalance marked by loss of beneficial microbes and overgrowth of pathogens. Christensenella intestinihominis, a bacterium that associated with intestinal homeostasis, is depleted in patients with ulcerative colitis (UC), yet its therapeutic potential against this disease remains to be elucidated. Here we demonstrate that C. intestinihominis AF73-05CM02, a strain isolated from Chinese individual, alleviates colitis. In healthy human gut, C. intestinihominis co-occurs with beneficial microbes in strongly connected networks, while these interactions are disrupted in UC. We employ the dextran sulfate sodium (DSS)-induced murine colitis model, a widely recognized preclinical model for investigating intestinal inflammation. In this model, oral gavage with AF73-05CM02 mitigates weight loss, ameliorates colonic injury, improves intestinal health markers, and reverses colon damage. It exerts these effects by reducing harmful bacteria such as Helicobacter species and increasing beneficial taxa like Akkermansia, while enhancing the intestinal epithelial barrier integrity and regulating immune responses. These findings indicate AF73-05CM02 may aid in the treatment of inflammatory bowel disease by restoring a healthy gut microbial community.