Results from a recent study provide more evidence that Alzheimer’s disease and dementia could be the result of an infectious bacteria. Researchers took brain tissue samples from deceased Alzheimer’s patients and found the exact same bacteria that has been linked to chronic gum disease: Porphyromonas gingivalis (P. gingivalis). During clinical testing, mice were exposed to this same bacteria. Brain tissue samples were measured and not only found to have been infected with P. gingivalis, but also contained some of the same biomarkers and proteins that are associated with Alzheimer’s disease.

​Furthermore, P. gingivalis was found in human brain tissue of patients who were not diagnosed with Alzheimer’s, providing more evidence that the gum disease, specifically P. gingivalis, could potentially contribute to these cognitive diseases. In the people aged 65 and older, 10% of the population suffers from Alzheimer’s and 70% suffer from advanced gum disease. Most people believe that dementia is the cause for improper oral hygiene in older adults. However, given the strong evidence, it’s possible that gum disease from improper oral hygiene increases chances of developing Alzheimer’s disease and/or dementia. Therefore, maintaining good habits throughout the life cycle may prevent the onset of cognitive decline observed in aging adults.

Dominy, S. S., Lynch, C., Ermini, F., Benedyk, M., Marczyk, A., Konradi, A., … & Holsinger, L. J. (2019). Porphyromonas gingivalis in Alzheimer’s disease brains: Evidence for disease causation and treatment with small-molecule inhibitors. Science advances5(1), eaau3333.