ORAL MICROBIOME AND BLOOD-BRAIN BARRIER. “We propose for a subset of AD patients, aging favors the overgrowth of oral anaerobes established earlier in life provoking a pro-inflammatory innate response that weakens the BBB allowing bacteria to spread and quietly influence the pathogenesis of AD.”
http://www.researchgate.net/profile/Deborah_Shoemark/publication/264794791_The_Microbiome_and_Disease_Reviewing_the_Links_between_the_Oral_Microbiome_Aging_and_Alzheimer’s_Disease/links/53fd9d340cf22f21c2f816ab.pdf