Researchers from Tuft’s University School of Dental Medicine have found that a common bacterium promotes the progression of both periodontal disease and Alzheimer’s disease. Jake Jinkun Chen, a professor of periodontology and director of the Division of Oral Biology at Tufts University School of Dental Medicine and his colleagues believe that controlling the pathogen called Fusobacterium nucleatum (F. nucleatum) will slow the progression of these diseases.

According to Brain Tomorrow, researchers have previously linked F. nucleatum to a range of conditions such as premature birth and colorectal cancer. In periodontal disease, bacteria affects the gum and jaw, causing loose teeth and loss of teeth. It can also exacerbate inflammation, which has been shown in previous studies to lead to cardiovascular disease and type 2 diabetes.

In Chen’s latest research, published in the journal Frontiers in Aging Neuroscience, the scientists found that F. nucleatum triggers abnormal growth of microglial cells in mice. These are the immune cells within the brain that remove damaged neurons and maintain the health of the central nervous system, says Brain Tomorrow. The abnormal growth of the microglial cells causes inflammation, which is considered significant in determining the neurodegeneration progression in Alzheimer’s patients.

“Our studies show that F. nucleatum can reduced the memory and thinking skills in mice through certain signal pathways,” said Chen. “This is a warning sign to researchers and clinicians alike.

“In this study, our lab is the first to find that F. nucleatum can generate systemic inflammation and even infiltrate nervous system tissues and exacerbate the signs and symptoms of Alzheimer’s disease,” Chen said in a statement from Tufts University.

Chen and his colleagues believe that by targeting F. nucleatum, they can slow the spread and progression of at least two epidemics — periodontal disease, which affects 47% of U.S. adults over the age of 30, and Alzheimer’s disease, which affects 6.5 million Americans currently, and is expected to rise to more than 14 million by 2060.

Possible links between periodontal disease and Alzheimer’s have been suggested by researchers in the past. This latest study doesn’t show that F. nucleatum-related periodontal disease leads directly to Alzheimer’s disease, but rather implies that if left untreated, it could make symptoms of Alzheimer’s disease worse. On the other hand, treating periodontal disease effectively could potentially slow Alzheimer’s progression.

“Testing for bacterial load and degree of symptoms could one day become a way to measure the effects of F. nucleatum and manage treatment to slow progression of both periodontal disease and Alzheimer’s,” said Chen. “Your mouth truly is the gateway to your body.”