Emerging evidence from in vitro and animal experiments, using either wild-type rodents or mouse AD models exposed to P. gingivalis or its LPSs, indicates that upon entry into the CNS, LPSs induce or exacerbate cognitive impairment and AD-like pathologies, including microglia-mediated neuroinflammation, gliosis, Aβ accumulation, the formation of hyperphosphorylated tau and NFTs, and neurodegeneration [23,24,25,83,89,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,178,179,180,181,182,183,184,185,186,187]. This evidence concerns the gene MAPT and Alzheimer disease.