Overview

An international team of researchers led by Cortexyme detail the role of a common bacterium, Porphyromonas gingivalis, in driving Alzheimer’s disease pathology.

The science and other stuff to know

About 47 percent of over 30-year-old and 70 percent of 65-year-old adults in the US have gum disease, according to the Centers for Disease Control and Prevention (CDC). Also called Periodontitis, the condition occurs through a bacterial infection within the mouth’s soft tissues. It has been linked to numerous diseases, such as diabetes, cardiovascular issues, and kidney disease.

A recent study also claims a correlation between gum disease and Alzheimer’s. In a paper published in Science Advances, an international team of researchers led by Cortexyme reported the discovery of Porphyromonas gingivalis (the bacteria behind gum disease) in the brains of deceased Alzheimer’s patients.

“Infectious agents have been implicated in the development and progression of Alzheimer’s disease before. But the evidence of causation hasn’t been convincing,” lead author of the study Stephen Dominysaid said in a press statement. “Now, for the first time, we have solid evidence connecting the intracellular, Gram-negative pathogen, P. gingivalis, and Alzheimer’s pathogenesis.”

By experimenting on mice, the study team found that oral infection with the pathogen led to brain colonization by the bacteria. It also led to increased production of amyloid beta (Aβ), the sticky proteins commonly associated with Alzheimer’s.

So what?

While the researchers don’t claim they have found definitive evidence of Alzheimer’s cause, they suggest that their findings add to the growing evidence that microbes and viruses may play a role in this form of dementia.

“The Science Advances publication sheds light on an unexpected driver of Alzheimer’s pathology, the bacterium commonly associated with chronic periodontal disease,” Casey Lynch, co-author of the paper, said. “It also details the promising therapeutic approach Cortexyme is taking to address the pathology with COR388.”

Dr. Percy Griffin, Director of Scientific Engagement of the Alzheimer’s Association and who wasn’t involved in the study, says:

“Previous studies examining the relationship between periodontal disease and Alzheimer’s in humans haven’t demonstrated causation. More research is needed.”

“We don’t know at this time whether things like brushing your teeth will ultimately reduce your risk for Alzheimer’s. What we can say is good oral hygiene is important for overall health and healthy aging. There are a number of other modifiable lifestyle risk factors — like exercise and diet — that have considerable scientific evidence to show they can reduce your risk for cognitive decline.”

What’s next?

Another new, ground-breaking study by researchers at Tufts University affirms the link between Alzheimer’s and gum disease through a bacterial called Fusobacterium nucleatum (F. nucleatum). We’ll have to wait and see what future studies will uncover about this correlation and treatment options.