The Relationship between Porphyromonas gingivalis and Alzheimer’s Disease
Stephen S. Dominy et. al., January 23, 2019. ScienceAdvances
Summarized by: Joe Masselli
Recently, an important oral-systemic relationship has been established between the presence of P. gingivalis in periodontitis lesions and the occurrence of Alzheimer’s Disease. It has been shown that gingipain proteases (virulence factors specific to P. gingivalis), correlate with tau protein dysfunction (via cleavage) leading to the production of amyloid beta plaques, which interfere with neuronal signaling. It has been hypothesized that polymorphisms in immune genes can lead to defective clearance of P. gingivalis from the CNS, indicating why some individuals are more susceptible to Alzheimer’s-associated neuroinflammation than others. Not only were gingipains isolated and shown to lead to tau hypophosphorylation and dysfunction, but when P. gingivalis itself was isolated and introduced into the oral cavity of mice, the bacteria was shown to invade the brain of all of the mice used. Interestingly, an orally administered inhibitor of gingipain protease (COR271) in combination with moxifloxacin was shown to significantly reduce CNS bacterial load, pointing to a potential treatment to be examined in larger studies in the future.