A recent study published in PLOS ONE suggests that periodontal (gum) disease may initiate Alzheimer’s Disease. Long-term exposure to periodontal disease bacteria causes inflammation and degeneration of brain neurons in mice that is like the effects of Alzheimer’s disease in humans, according to this study from researchers at the University of Illinois at Chicago (UIC).
Although other studies have demonstrated a close association between periodontitis and cognitive impairment, 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 patients.
To study the impact of the bacteria on brain health, UIC established chronic periodontitis in 10 wild-type mice. Another 10 mice served as the control group. After 22 weeks of repeated oral application of the bacteria to the study group, the researchers studied the brain tissue of the mice and compared brain health.
The researchers found that the mice chronically exposed to the bacteria had significantly higher amounts of accumulated amyloid beta — a senile plaque found in the brain tissue of Alzheimer’s patients. The study group also had more brain inflammation and fewer intact neurons due to degeneration.
These findings were further supported by amyloid beta protein analysis, and RNA analysis that showed greater expression of genes associated with inflammation and degeneration in the study group. DNA from the periodontal bacteria was also found in the brain tissue of mice in the study group, and a bacterial protein was observed inside their neurons.
This data, according to the researchers, not only demonstrates the movement of bacteria from the mouth to the brain, but also that chronic infection leads to neural effects like Alzheimer’s.
The researchers say these findings are powerful in part because they used a wild-type mouse model; most model systems used to study Alzheimer’s rely on transgenic mice, which have been genetically altered to more strongly express genes associated with the senile plaque and enable Alzheimer’s development.
In conclusion, since gum disease is a risk factor for the development of Alzheimer’s, it is critical that you see your dentist regularly and observe good oral hygiene practices.