Alzheimer’s is a devastating disease that often requires early diagnosis in order to be effectively treated, but there is still no cure for the disease and very little evidence as to its cause. Now, a new research effort is pointing to a link between Alzheimer’s and something you might not expect: gum disease.

The study, which was published in Science Advances, investigated the potential link between a type of bacteria associated with gum disease and the affects of Alzheimer’s on the brain. Lab tests using mice demonstrated the potential of the bacteria Porphyromonas gingivalis to travel from the mouth of a subject to its brain, resulting in the destruction of neurons.

The bacteria assaults the brain cells with a hostile protein while also promoting the formation of plagues in brain tissue that are found in Alzheimer’s patients. This would seem to be a pretty cut-and-dry investigation with some pretty dramatic results, but other scientists in the field aren’t completely sold on the findings.

As BBC reports, there are some serious questions left to be answered. Most notable is whether or not the bacteria promotes Alzheimer’s or if it’s simply a byproduct of the brain disease. Alzheimer’s patients may be less capable of fighting off brain infections, meaning that it’s possible that the disease is opening the gateway for the bacteria to invade the brain, rather than the other way around.

This is just one of several potential breakthroughs in Alzheimer’s research coming in January. Earlier this week, researchers from Washington State University announced the development of a new kind of blood test that seems to be able to predict onside of the disease as long as 16 years before symptoms actually emerge.