Is this what causes Alzheimer’s? And is a vaccine in sight?

Porphyromonas Gingivalis is the key bacteria that leads to chronic gum disease. This can cause your gums to bleed so if yours bleed when you brush your teeth you may want to get them looked at. Doctors have long believed that brain infection is at the root of Alzheimer’s disease (AD) and decided to look at the dental link.

As a result, a drug that blocks the main toxins of P. gingivalis is entering clinical trials this year as recent research shows it may stop and even reverse Alzheimer’s disease, and possibly give rise to a vaccine. 

In this recent study, researchers from the US, Europe, New Zealand and Australia looked for Porphyromonas gingivalis and toxins released by it in brain samples from people who had died with Alzheimer’s. 

They found the toxins in nearly all (up to 99%) of the brain samples, with the highest concentrations in samples that had the most beta-amyloid plaques and tau tangles, classic hallmarks of Alzheimer’s.

AD is a medical mystery. As our populations age and grow so does dementia, which is now the 5th biggest cause of death around the globe. AD constitutes to some 70% of these deaths, yet what causes it is not fully understood. 

Porphyromonas Gingivalis has been found to invade and inflame brain regions affected by AD; gum infections worsen symptoms in AD model mice; and it causes AD-like brain inflammation, neuronal damage, and amyloid plaques in healthy mice. 

Those who had experienced worse cognitive decline were found to have had the bacteria and its enzymes in higher levels. The bacteria was also found in the spinal fluid of those living with the disease, suggesting that the technique may provide a method of diagnosis. 

An oral drug that Cortexyme, the San Francisco–based biotech company that sponsored the research developed specifically for the study not only blocked the gingipain* toxins—it also halted the brain degeneration. The drug specifically inhibits the different types of gingipains enzymes secreted by P. gingivalis by irreversibly binding to the active catalytic site of the gingipains enzymes, permanently inhibiting their activity.

Phase 2 clinical trials to test the drug on people with mild to moderate Alzheimer’s are planned for later this year.

*Gingipain is a protease secreted by Porphyromonas gingivalis. Among other functions, they work to degrade cytokines, thereby downregulating the host response in the form of reduced inflammation.