Links between gum disease and Alzheimer's

Did you know there's a link between periodontal infection and Alzheimer's? The link is primarily mediated through systemic inflammation and the actions of specific periodontal pathogens. Chronic periodontitis can lead to systemic inflammation, which has been implicated in the pathogenesis of Alzheimer's disease (AD).

Several studies have highlighted the role of pro-inflammatory cytokines such as IL-1β and TNF-α in this process. These cytokines, upregulated during periodontal infections, can promote a pro-inflammatory environment in the brain, contributing to AD-like pathology and cognitive dysfunctions.[1]

Porphyromonas gingivalis, a key pathogen in periodontitis, has been shown to induce systemic inflammation, amyloid β protein deposition, and tau protein hyperphosphorylation, leading to AD-like lesions. This pathogen can alter gut microbiota and disrupt the gut-brain axis, further exacerbating AD pathology.[2] Additionally, bacterial membrane vesicles from P. gingivalis can cross the blood-brain barrier, initiating physiological changes associated with AD.[3]

Moreover, chronic systemic exposure to P. gingivalis lipopolysaccharide (PgLPS) has been shown to promote neuroinflammation and tau hyperphosphorylation in animal models, leading to cognitive deficits.[4] The presence of periodontal pathogens in the brain, such as P. gingivalis, has been detected in autopsy specimens from individuals with AD, suggesting a direct microbial involvement in AD pathogenesis.[5]

In summary, the link between gum disease and Alzheimer's disease is supported by evidence of systemic inflammation, direct microbial invasion, and the resultant neuroinflammatory and neurodegenerative processes.

1. IL-1β and TNF-α Play an Important Role in Modulating the Risk of Periodontitis and Alzheimer's Disease.

Wang RP, et al. J. Neuroinflammation. 2023;20(1):71. doi:10.1186/s12974-023-02747-4.

2. Porphyromonas Gingivalis Induces Disturbance of Kynurenine Metabolism Through the Gut-Brain Axis: Implications for Alzheimer's Disease.

Zhu H, et al. J. Dental Research. 2025;:220345241303141. doi:10.1177/00220345241303141.

3. Bacterial Membrane Vesicles: The Missing Link Between Bacterial Infection and Alzheimer Disease. Butler CA, et al.

The Journal of Infectious Diseases. 2024;230(Supplement_2):S87-S94. doi:10.1093/infdis/jiae228.

4. GSK3β Is Involved in Promoting Alzheimer's Disease Pathologies Following Chronic Systemic Exposure to Porphyromonas Gingivalis Lipopolysaccharide in Amyloid Precursor Protein Knock-in Mice. Jiang M, et al.

Brain, Behavior, and Immunity. 2021;98:1-12. doi:10.1016/j.bbi.2021.08.213. 

5.Porphyromonas Gingivalis and Alzheimer Disease: Recent Findings and Potential Therapies.

Ryder MI. Journal of Periodontology. 2020;91 Suppl 1:S45-S49. doi:10.1002/JPER.20-0104