The link between oral bacteria and the brain: what you need to know

Alzheimer's disease and dementia are two of the most common neurodegenerative disorders, affecting millions of people worldwide. Although their exact causes are still unknown, scientists have been researching potential risk factors for decades. One such factor that has gained increasing attention in recent years is the role of oral bacteria in the development of these conditions.

The human mouth is home to trillions of bacteria, which play a crucial role in maintaining oral health. However, some of these bacteria can also cause infections and inflammation, leading to gum disease and tooth decay. The same bacteria that cause these oral health problems can also enter the bloodstream and travel to other parts of the body, including the brain.

Studies have found that certain types of oral bacteria, such as Porphyromonas gingivalis, can produce enzymes that break down the amyloid beta protein found in the brains of Alzheimer's patients. This breakdown can cause the protein to form clumps or plaques, which are a hallmark of the disease. In addition, these bacteria can also trigger an immune response that leads to inflammation, which is another potential risk factor for Alzheimer's disease.

One study published in the Journal Science Advances found that mice infected with P. gingivalis showed increased levels of amyloid beta and inflammation in their brains. These mice also performed worse on cognitive tests compared to healthy mice. The researchers also found evidence of the bacteria in the brains of deceased Alzheimer's patients, suggesting a possible link between oral bacteria and the development of the disease.

Another study published in the Journal of Alzheimer's Disease found that individuals with periodontitis, a severe form of gum disease, had a higher risk of developing dementia compared to those without the condition. The researchers hypothesized that the inflammation caused by the bacteria in the mouth may contribute to brain inflammation and cognitive decline.

Although these studies provide intriguing evidence for the link between oral bacteria and Alzheimer's disease and dementia, more research is needed to establish a causal relationship. However, they do suggest that maintaining good oral hygiene may be an important factor in reducing the risk of these conditions.

In conclusion, the connection between oral bacteria and Alzheimer's disease and dementia is an area of ongoing research. While the exact mechanism by which these bacteria contribute to the development of these conditions is not yet fully understood, studies suggest that reducing inflammation caused by oral bacteria may be an important factor in reducing the risk of Alzheimer's disease and dementia. Therefore, maintaining good oral hygiene practices, such as regular brushing and flossing, may be beneficial for both oral health and overall brain health.

Measuring the bacteria in your mouth through saliva testing, such as the peri oral health test, can provide valuable insights into your potential risk for other health issues. Testing can serve as an invaluable tool to monitor the effectiveness of your oral health practices and interventions. It allows you and your healthcare providers to track improvements, make necessary adjustments, and ensure your mouth is not putting you at risk for systemic diseases.


Dominy, S. S., et al. (2019). Porphyromonas gingivalis in Alzheimer's disease brains: Evidence for disease causation and treatment with small-molecule inhibitors. Science Advances, 5(1), eaau3333.

Kamer, A. R., et al. (2015). Periodontal disease associates with higher brain amyloid load in normal elderly. Neurobiology of Aging, 36(2), 627-633.

About Dr. Kantor

Alexandra Kantor is a prominent dentist and entrepreneur, known for her contributions to the dental industry. With over 10 years experience as a practicing dentist, she has gained a deep understanding of her patient's oral health and overall well-being. In 2022, Dr. Kantor founded peri, an at-home saliva test that specializes in analyzing key bacteria within the mouth. Dr. Kantor holds a Doctor of Dental Surgery degree from the Indiana School of Dentistry and is dedicated to promoting oral health through advanced technology.