February 5, 2019
Porphyromonas gingivalis in Alzheimer’s disease brains: Evidence for disease causation and treatment with small-molecule inhibitors (Stephen S. Dominy et.al.) Science Advances 23 Jan 2019: Vol. 5, no. 1
New evidence from respected multicenter hospitals and clinics (including UCSF and Forsyth) demonstrate a clear link between a bacterial species involved in periodontal disease and the creation of beta-amyloid plaque and tau “tangles” that are characteristic of Alzheimer’s Disease.
It is hypothesized that the bacteria and bacterial products, which are found in the brains, and cerebrospinal fluid sampled with a lumbar needle, travel from the oral cavity to the brain through the blood vessels or more directly, through the cranial nerves that supply the teeth and oral tissues.
These bacteria are one of the most common periodontal pathogens causing periodontal diseases. They are tissue invasive and can live within a host cell, escaping the immune system and exposure to antibiotics. They elaborate “virulence” factors known as gingipains, which either kills neurons directly, or indirectly via cutting proteins in the brain. Some of these proteins are tau and beta amyloid, which in their intact form are thought to be protective against bacteria. The broken fragments form clumps or tangles that are found in Alzheimer’s Disease.
This is new information and may result in new guidelines concerning periodontal diseases and Alzheimer's Disease. Consistent with what is known before, we can not separate oral health from overall systemic health. Awareness of periodontal pocketing and appropriate treatment may offer other benefits as well (cardiovascular, etc.). Detection of disease may lead to increased surveillance and treatment.
This new study offers an improved mode of therapy, beyond antibiotics, to medicines that may target these bacteria. Only after years of testing will there be a marketed therapy aimed at inactivating the virulence factors that the bacteria rely on, thus slowing Alzheimer’s disease. Until then, appropriate dental care and at home hygiene will be essential.
If you have any questions or concerns about periodontal disease and its affect on pregnancy, please ask your dentist.