- Research has found a link between Alzheimer’s disease and a type of bacteria known to cause gum disease.
- Alzheimer’s disease is a type of dementia that leads to the loss of the ability to think and remember.
- Scientists think this bacteria may make Alzheimer’s symptoms worse by increasing inflammation.
- Gum disease treatment and prevention might help slow the progression of Alzheimer’s disease.
- Good oral hygiene may also help prevent several other diseases linked to this bacteria.
Fusobacterium nucleatum (F. nucleatum) is a common bacteria associated with oral conditions like gum disease, bad breath, tooth abscess, and mouth cancer. In addition, it has been linked to a variety of diseases elsewhere in the body, including cancers, infections, and inflammatory conditions.
Most recently, a study published in Frontiers in Aging Neuroscience has found that it may also be linked to Alzheimer’s disease.
The Alzheimer’s Association describes Alzheimer’s disease as being the most common cause of dementia, making up about 60-80% of all cases. It is a progressive condition with no cure.
People with Alzheimer’s disease experience, a gradual loss of memory and cognition, eventually becoming severe enough to interfere with their daily functioning. It is believed to be caused by a buildup of beta-amyloid and tau proteins in the brain that damages and kills nerve cells.
Lead author Jake Jinkun Chen, DMD, MDS, and PhD, Professor of Periodontology and Director of the Division of Oral Biology at Tufts University School of Dental Medicine, said his team’s work, which was done using mice, showed that F. nucleatum might worsen Alzheimer’s disease, either by creating inflammation or by taking up residence in the brain and secreting pathological molecules.
“Our studies show that F. nucleatum can reduce the memory and thinking skills in mice through certain signal pathways,” said Chen. “This is a warning sign to researchers and clinicians alike.”
While it might seem odd that bacteria found in the mouth could have such far-reaching effects, Chen said, “Your mouth truly is the gateway to your body.”
Chen further explained that F. nucleatum causes abnormal growth of microglial cells. Microglial cells are immune cells in the brain that normally remove damaged nerve cells and infections. This excessive growth of microglial cells creates an increased inflammatory response.
“Chronic inflammation or infection is believed to be a key determinant in the cognitive decline that occurs as Alzheimer’s disease progresses,” said Chen.
Chen noted that while his research does not prove that periodontal disease can cause Alzheimer’s disease, it does suggest that if you don’t adequately treat gum disease, you might make Alzheimer’s disease symptoms worse.
Additionally, treating gum disease in the early stages of Alzheimer’s could potentially slow its progression.
Chen believes that testing for bacterial load and degree of symptoms could one day become a way to measure the effects of F. nucleatum and monitor the course of the disease.
He feels this work is significant because most adults have periodontal disease, and many will develop Alzheimer’s disease later on. Understanding how this type of bacteria affects Alzheimer’s would help dentists and neurologists better understand the interplay between these two conditions.
He adds that the next step in his research will be to use a particular microRNA to target the major causes of Alzheimer’s, including the formation of amyloid plaques, the deposition of tau protein, and brain inflammation.
He said his goal is to find “a robust and effective ‘in-one-go’ approach leading to the discovery of effective, safe, and efficient treatment strategies for Alzheimer’s disease.”
Chen noted that gum disease affects 47 percent of Americans over the age of 30, while Alzheimer’s currently affects about 6.5 million people
“Given the growing body of work — including this study — examining the connections between the two, we hope that people will take seriously the importance of maintaining good oral hygiene to maintain cognitive and overall health.”
Ana Karina Mascarenhas, BDS, MPH, DrPH, FDS RCPS (Glasg), Professor and Associate Dean of Research and Community Health at Woody L. Hunt School of Dental Medicine, Texas Tech University Health Sciences Center El Paso, said it’s essential to have a “structured and diligent” oral hygiene routine, consisting of the following:
- Brush your teeth twice daily, preferably after meals. “This would mean after breakfast and last thing before going to bed. Brushing after lunch would help too,” she said.
- Use fluoride toothpaste. This helps prevent cavities, according to the American Dental Association (ADA).
- Avoid tobacco products and vaping. These can increase the risk of inflammation and gum disease, Mascarenhas explained.
- Visit a dentist at least once a year for a checkup. The ADA says regular checkups help detect problems early when they are easier and less expensive to treat.
- Follow your dentist’s advice diligently. This includes using a mouth rinse or other recommended oral hygiene aids, said Mascarenhas.
- Get regular cleanings by a dental hygienist. Your dentist can recommend how often to do this, based on your personal needs, she said.
Mascarenhas further advised that even if you don’t have Alzheimer’s disease, there are many other compelling reasons to take care of your gums and teeth.
In addition to F. nucleatum‘s emerging link to Alzheimer’s, gum disease has been associated with several other diseases, with that list continuing to grow.
Certain cancers, pre-term births, stroke, cardiovascular diseases, and diabetes have been linked to poor oral hygiene, she said.
With diabetes, in particular, she said there is good evidence that those with untreated gum disease are more likely to be unable to control the condition. “The consequences of uncontrolled diabetes are debilitating, including loss of limbs,” she said.