Our findings reveal several novel insights: (1) all participants with subjective constipation predominantly belonged to the Lachnospiraceae enterotype (ET-L) compared with individuals without subjective symptoms of constipation; (2) the increased abundance of mucin-degrading bacteria, particularly in those with CAG3 and CAG9, was positively associated with delayed transit time; and (3) specific dietary components showed significant positive correlations with mucin-degrading bacteria abundance and transit time. The gene discussed is MUC5AC; the disease is constipation disorder.