A new study from researchers in Japan has found a possible link between gum disease and multiple sclerosis (MS), a condition that affects the brain and spinal cord.
The research focused on a common mouth bacterium called Fusobacterium nucleatum, which may make MS symptoms worse. These findings could open up new ways to manage MS by improving oral health.
Multiple sclerosis is a disease where the immune system attacks the protective covering of nerve cells, called the myelin sheath. This leads to communication problems between the brain and the body.
People with MS can suffer from muscle weakness, balance problems, and vision issues. While the exact cause of MS is unknown, scientists believe it may be triggered by infections, vitamin deficiencies, smoking, or genetic factors.
In Japan, MS has become more common since the 1980s. This rise could be due to environmental changes. Many studies have looked at gut bacteria and how they might be involved in MS. But this new research turned attention to the bacteria in the mouth—especially those involved in gum disease.
Gum disease, or periodontitis, is a long-term infection that causes inflammation in the gums. It affects nearly half of the global population and can lead to tooth loss. It is also known to raise the risk of other diseases like heart disease, diabetes, and arthritis.
In this study, scientists collected tongue coating samples from people with MS and two other similar diseases: neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). They wanted to see if the levels of certain oral bacteria were connected to how severe the diseases were.
They found that MS patients with high levels of Fusobacterium nucleatum in their mouth had more severe disability, as measured by the Expanded Disability Status Scale (EDSS).
These patients were also more likely to have other harmful bacteria in their mouth. Interestingly, this link was not found in patients with NMOSD or MOGAD. This suggests that gum bacteria may have a unique effect in MS.
To define “high levels,” the researchers looked at the top 25% of patients with the most Fusobacterium nucleatum. Nearly 62% of these patients had moderate to severe disability (EDSS score of 4 or more), while only 19% of patients with lower levels of the bacteria had such disability.
Even when the researchers took into account other factors like age, MS type, and how long a person had been sick, the link between the bacteria and MS severity remained strong.
The scientists believe that Fusobacterium nucleatum might act as a “bridge bacterium”—connecting other bacteria in the mouth and possibly linking mouth inflammation to brain inflammation.
The team now hopes to do larger studies to confirm these findings. They also plan to explore how exactly the bacteria might influence the immune system in MS. One goal is to see if dental treatments or better oral hygiene could help reduce symptoms or slow the progression of the disease.
This new research points to the possibility that taking care of your mouth may not only protect your teeth but also your brain. If proven, this could lead to new ways to treat MS by focusing on oral health.
If you care about tooth health, please read studies about an important causes of tooth decay and gum disease, and common tooth disease that may increase risks of dementia.
For more health information, please see recent studies about mouthwash that may increase your tooth damage, and results showing this diet could help treat gum disease.
The study is published in Scientific Reports.
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