For example, ligature-induced chronic periodontitis and repeated oral exposure to P. gingivalis produce gut microbiota shifts, intestinal barrier impairment, increased circulating LPSs and pro-inflammatory cytokines, and activation of innate pathways (i.e., NLRP3), culminating in BBB disruption, microglial activation, increased Aβ/tau pathology, and cognitive deficits in mice [128,129]. The gene discussed is MAPT; the disease is periodontitis.