P. gingivalis infection can lead to systemic and brain inflammation. This inflammation activates microglia and astrocytes, increasing the production and deposition of Aβ.The infection triggers the release of pro-inflammatory cytokines, exacerbating neuroinflammation and promoting Aβ accumulation.P. gingivalis produces enzymes called gingipains, which can degrade neural proteins and disrupt normal brain function. These enzymes can also interact with APP, increasing Aβ production.The frontal cortex and hippocamous are mainly affected by P. gingivalis-induced inflammation and Aβ deposition. Here, APP is linked to brain inflammatory disease.