Periodontal Disease May Spur Alzheimer's

A study published in PLOS One suggests periodontal disease could trigger Alzheimer's in humans based upon inflammation and degeneration of brain neurons in mice, reports United Press International . University of Illinois at Chicago Professor Keiko Watanabe acknowledges that other studies found a close linkage between periodontitis and cognitive impairment, "but this is the first study to show that exposure to the periodontal bacteria results in the formation of senile plaques that accelerate the development of neuropathology found in Alzheimer's subjects." The scientists established chronic periodontitis, marked by soft tissue damage and bone loss in the oral cavity, in 10 mice, while 10 mice served as controls. Following 22 weeks of repeated oral application of the bacteria, brain tissue analysis revealed that mice chronically exposed had significantly higher amounts of accumulated amyloid beta and greater brain inflammation and fewer intact neurons due to degeneration. Furthermore, amyloid beta protein and RNA analyses exhibited greater expression of genes associated with inflammation and degeneration in the study group. Moreover, DNA from the periodontal bacteria was identified in the brain tissue of mice and a bacterial protein was discovered inside their neurons in the study cohort. "Our data not only demonstrate the movement of bacteria from the mouth to the brain, but also that chronic infection leads to neural effects similar to Alzheimer's," Watanabe notes.