The Link Between Gum Disease and Alzheimer’s Disease: Fusobacterium Nucleatum

Common bacteria that can cause gum disease, Fusobacterium nucleatum, may explain the link between periodontitis and Alzheimer’s disease. Researchers suspect that preventing or treating gum disease could prevent periodontitis as well as Alzheimer’s disease.

man with alzheimer's

Fusobacterium nucleatum has been found to cause brain inflammation seen in Alzheimer's disease.

©kupicoo | Getty Images

According to the Cleveland Clinic, periodontitis is a later stage of gum disease caused by bacteria that infect your gums and the spaces around your teeth. Periodontitis may increase your risk for tooth loss. It has also been linked to a higher risk of Alzheimer’s disease, but the reason has been a mystery.

What is Fusobacterium nucleatum

A new study from Tufts University School of Dental Medicine suggests that bacteria commonly found in the mouth called  Fusobacterium nucleatum may be the culprit. Most of the time these bacteria live in your mouth without causing any problem, but if you have poor oral hygiene or other risk factors for gum disease like smoking or diabetes, these bacteria can enter the tissue inside your gums, multiply, and cause infected gums. Early gum infection is called gingivitis. If gingivitis goes untreated, the infection can become more advanced, called periodontitis.

F nucleatum is what researchers call an emerging pathogen, which means it is showing up in unexpected places. It should not be found anywhere outside the mouth, but when it causes gum infection it has the ability to travel to other areas of the body. These bacteria have a high risk of causing disease in the body because they are adhesive, invasive, and inflammatory. That means they can linger and mix with other bacteria, they can invade cells and tissues, and they cause a lot of swelling and irritation.

When F nucleatum infects the gums, it has been linked to diseases that include poor pregnancy outcomes, colon cancer, inflammatory bowel disease, appendicitis, atherosclerosis, diabetes, lung infections, and brain aneurysm. The new study has found the bacteria could cross from the blood and into the brains of mice causing a type of brain inflammation seen in Alzheimer’s disease.

Gingivitis and Periodontitis

Gingivitis is swelling of your gums. It starts when you don’t brush or floss your teeth regularly and bacteria combine with secretions in your mouth to form a film over your teeth called plaque. Because F nucleatum are adhesive bacteria, they are often involved in plaque buildup. A buildup of too much plague is called tartar. Untreated gingivitis progresses to periodontitis causing red swollen and bleeding gums. Deep inside your gums pockets of bacteria can form between your teeth and gums, eventually causing loosening of your teeth and tooth loss. Studies show that F nucleatum bacteria thrive in these deep infections.

As your gums pull away from your teeth (receding gums), it makes your teeth look longer.  Other signs of gum infection are gums that are red, swollen, and tender. Infected gums bleed easily, so you may see blood when you brush or floss. Gum disease may cause painful chewing and bad breath.

How to Prevent Periodontitis and the Spread of F nucleatum

Periodontitis is surprisingly common. It may occur in almost half of adults over age 30 and up to 70 percent in people over age 65. The good news is that it can be prevented with good oral hygiene and dental care.

Start by brushing your teeth morning and night, flossing every day, and not smoking. If you have diabetes, work with your doctor to get your blood sugar under the best control. See your dentist for regular cleaning and removal of plaque or tartar. In most cases, this will prevent or greatly reduce your risk of periodontitis.

Treatment of periodontitis may require deep cleaning procedures called tooth scaling and planing. Periodontal surgery may be needed to open deep pockets of disease near your tooth roots, called flap or pocket reduction surgery. You may also need to use an antibacterial mouthwash or gum gel.

Making the commitment to good oral hygiene and dental care is about more than keeping your teeth. Research continues to show that what happens in your mouth does not stay in your mouth. Avoiding gum disease may also prevent invasion of F nucleatum and a host of other conditions you don’t want, including Alzheimer’s disease.

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Chris Iliades, MD

Dr. Chris Iliades is board-certified in Ear, Nose and Throat and Head and Neck Surgery from the American Board of Otolaryngology and Head and Neck Surgery. He holds a medical … Read More

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