Periodontitis, a chronic oral inflammatory disease-causing tissue damage, bone deterioration and tooth loss, has been linked to Alzheimer’s disease. Porphyromonas gingivalis, a key bacterium causing periodontitis, has been found in the brain of Alzheimer’s disease patients, and it is believed to contribute to brain pathology. However, there is a lack of direct evidence connecting periodontitis with Alzheimer’s disease. This study will investigate how infection by Porphyromonas gingivalis contributes to Alzheimer’s disease. Using animal modeling, the researcher will determine how Porphyromonas gingivalis reaches the brain. The investigation will include looking at how Porphyromonas gingivalis disrupts brain cells to trigger inflammation and brain changes often seen in Alzheimer’s disease. Reducing Porphyromonas gingivalis in the mouth or lowering its propagation to the nervous system may reduce the risk of Alzheimer’s disease and/or diminish the severity of brain damage seen in the late stages of this disease.