After FMT, the GM composition and SFCAs of Tg mice was improved. At the phylum level, Bacteroidetes increased, Proteobacteria and Verrucomicrobia decreased. Cognitive impairment was improved, Tau phosphorylation and Aβ40/42 were decreased, COX-2 and CD11b levels were decreased, and synaptic plasticity (PSD, synaptophysin I) was increased. Here, MAPT is linked to Cognitive impairment.