5 Surprising Ways the Health of Your Mouth Impacts Your Body

1) Heart Health

Numerous studies highlight an association between oral bacteria and cardiovascular diseases. A study from the American Heart Association, published in 2021, found that people with gum disease have higher levels of LDL (“bad”) cholesterol in their blood than those with healthy gums.

Another recent study, in Postgraduate Medical Journal, shows exactly how oral dysbiosis damages arterial health. Researchers found that chemicals produced by high-risk oral bacteria can make the walls of the artery more permeable and vulnerable to the invasion of LDL cholesterol. These bacteria also produce substances that make the inner lining of the arterial wall stickier, so it’s more likely to trap bad cholesterol and generate plaque deposits.

Malterud often partners with a cardiovascular specialist who sends him heart patients with oral dysbiosis. “[My colleague’s] biggest thing is reducing oral inflammation and problems like chronic infections following root canals that fail to heal, because he’s concerned about how oral inflammation can set up cardiovascular disease, coronary artery disease, and cerebral vascular disease,” he says.

Studies indicate that tracking oral health can be especially important for anyone whose genetic predisposition puts them at greater risk for cardiovascular events.

2) Metabolic Health

Research indicates a bidirectional relationship between periodontal disease and diabetes. Oral inflammation caused by dysbiosis can worsen insulin resistance, and both types 1 and 2 diabetes can exacerbate periodontal disease, creating a vicious cycle.

“Bacteria love sugar, and they love unregulated sugar in the blood,” Thompson says.

A Cochrane Review published in 2022 found ­moderate-certainty evidence that periodontal treatment improves glycemic control “by a clinically significant amount” in people with both periodontitis and diabetes. 

3) Cognitive Health

Anything that damages the cardiovascular system is bad news for the brain, so it’s not surprising that the risks posed by oral dysbiosis extend to cognitive health. An increasing body of evidence points to chronic inflammation and microbial dysbiosis as risk factors for Alzheimer’s. Studies typically connect oral inflammation to the systemic inflammation involved in neurodegeneration and dementia.

Malterud points to new research suggesting a possible connection between oral pathogens and Parkinson’s disease. In a small study, researchers found that early- to mid-stage Parkinson’s patients had higher levels of oral inflammation than healthy controls, even though the groups had similar amounts of plaque.

A few microbes, includ­ing S. mutans, were more abundant in the mouths of Parkinson’s patients. S. ­mutans is linked to the formation of amyloid plaques, which can contribute to cerebral inflammation. 

4) Immune Function

The oral microbiome plays a crucial role in regulating the immune system. Healthy oral bacteria help maintain immune homeostasis; dysbiosis can lead to chronic inflammation and immune dysregulation. This can increase the body’s susceptibility to infections and other immune-related conditions, including autoimmunity.

Research has also indicated that disruptions in the oral microbiome can contribute to the development of allergic reactions, including asthma and peanut allergies.

Studies have shown that certain oral pathogens associated with joint inflammation are more prevalent in patients with rheumatoid arthritis. Other research suggests periodontal disease may increase the odds of a longer, more severe ­COVID-19 infection, mainly by promoting viral adherence and persistence in the mouth.

Research has also indicated that disruptions in the oral microbiome can contribute to the development of allergic reactions, including asthma and peanut allergies.

5) Cancer Resistance

Oral dysbiosis has been correlated with a range of gastrointestinal (GI) cancers, including those of the mouth, esophagus, stomach, colon, and pancreas.

In a study published in ­Nature in 2024, researchers examined F. nucleatum, one of the bacteria implicated in gum disease. The mouth normally contains small amounts of this bacterium, but in an imbalanced oral microbiome it can overgrow and trigger inflammation. The study noted that F. nucleatum is rarely found in the guts of healthy people, but it has been identified in some colorectal cancer tumors, suggesting it may travel from the mouth through the digestive tract and contribute to tumor formation.

F. nucleatum is rarely found in the guts of healthy people, but it has been identified in some colorectal cancer tumors, suggesting it may travel from the mouth through the digestive tract and contribute to tumor formation.

Barnett notes the oral pathogen P. gingivalis can survive the highly acidic environment of the stomach and migrate to the colon, causing a variety of digestive disorders. It has also been linked to GI cancers.

Because chronic inflammation is a risk factor for all cancers, oral inflammation may increase the risk of non-GI cancers as well. Studies have indicated associations between periodontal disease and an increased risk of lung cancer. A research team at Imperial College of London found that a history of gum disease increased the risk of kidney cancer by 49 percent and blood cancers, such as leukemia, by 30 percent in male subjects.

The burden oral dysbiosis puts on the immune system means oral health is particularly important for those undergoing cancer treatment, Malterud says. “When someone is going through cancer therapy, one of the best things they can do is stay on top of their oral health.” (The health of the body’s internal ecosystem can determine how well the body resists cancer, both before and after a diagnosis. Learn more at “What Is the Terrain Theory of Cancer?“)