MAPT and Alzheimer disease: However, intestinal dysbiosis abnormally activates glial cells, potentially propagating Aβ toxicity, increasing Aβ accumulation, or releasing proinflammatory cytokines and reactive oxygen species, all of which are harmful to neurons, facilitate tau pathology, and further exacerbate inflammation, leading to neuronal damage and the progression of AD pathology (Yang and David, 2018; Ashley et al., 2022).