A. mucinipila is an important gram‐negative anaerobic bacterium, and it can degrade mucin in gut.[52] This bacterium is positively correlated with colonic tumor burden.[53] Our results showed that A. mucinipila was enriched both in male ApcMin/+ mice and pseudo germ‐free mice receiving male ApcMin/+ feces. The gene discussed is MUC5AC; the disease is colonic neoplasm.