APP and Alzheimer disease: For example, acetic acid, the top microglia-associated microbial metabolite, is involved in 446 microglia–microbial metabolite–gene–pathway–phenotype interactions in AD, including microglia-acetic acid-APP-inflammasomes-tau protein deposits, microglia-acetic acid-NOS3-calcium signaling-abnormal long-term potentiation, microglia-acetic acid-VEGFA-cytokine-cytokine interaction-astrocytosis, among others.