MAPT and tauopathy: In terms of AD pathology research, both the amyloid deposition theory and the tau pathology theory are widely recognized theories of AD pathogenesis, and gut microbiota plays a key role in amyloid production and pathogenesis in AD, affecting tauopathy in mouse models (Pistollato et al., 2016; Harach et al., 2017; Sun et al., 2019).