MAPT and Alzheimer disease: MGBA drives the onset and progression of AD through core pathological processes such as gut barrier function damage induced by gut microbiota dysbiosis, peripheral inflammatory mediators (such as LPS and SCFAs) entering the bloodstream, increased blood-brain barrier permeability, activation of neuroinflammation, and Aβ deposition and Tau protein phosphorylation (Harach et al., 2017; Gao et al., 2019; Liu et al., 2019; Chandra et al., 2023).