MAPT and Alzheimer disease: A growing body of clinical and experimental evidence suggests that the composition of the GM may also influence aging and influence brain disorders, such as Alzheimer’s disease (AD) (Cattaneo et al., 2017; Verhaar et al., 2022), a characteristic of which is the accumulation of amyloid plaques containing the amyloid-β (Aβ) peptide and fibrillary tangles composed of hyperphosphorylated tau.