The abundances of Mogibacteriaceae and Proteobacteria were positively correlated with the ratio of Aβ42 to Aβ40 in individuals with mild cognitive impairment, and the abundance of Enterobacteriaceae was positively correlated with p‐tau and the ratio of p‐tau to Aβ42 levels [19]. The gene discussed is MAPT; the disease is Cognitive impairment.