Mind Your Mouth: Impact of Oral Bacteria on Alzheimer's Disease

Abstract

Background: Emerging evidence suggests a compelling nexus between periodontitis, a chronic inflammatory disease associated with an oral infection, and the development of Alzheimer's disease. Porphyromonas gingivalis, a keystone periodontal pathogen, has been detected in Alzheimer's disease-affected brain tissue and implicated in triggering neuroinflammation and promoting hallmark pathologies, including amyloid-beta accumulation and tau hyperphosphorylation, through virulence factors such as gingipains. With Alzheimer's disease posing a mounting global health challenge and periodontitis affecting a significant portion of the population, recognizing this link is both timely and critical. Methods: This editorial explores the biological and epidemiological evidence linking periodontal health to cognitive decline, evaluating studies on pathogen presence, inflammatory mechanisms, and associations between oral infection and neurodegeneration. Results: Evidence indicates that oral infections, particularly periodontitis, may play a more central role in neurodegeneration than previously acknowledged. Detection of periodontal pathogens in brain tissue, along with mechanistic studies demonstrating promotion of hallmark Alzheimer’s pathologies, highlights the potential impact of chronic oral inflammation on cognitive decline. Conclusion: An integrated healthcare approach uniting dentistry, neurology, and public health is needed to prioritize oral health as a modifiable risk factor for dementia. Early diagnosis and treatment of periodontitis may represent a promising and underutilized strategy to reduce systemic inflammation and mitigate the risk of Alzheimer's disease.