By A.J. Hostetler 

Brushing and flossing aren’t just about keeping the teeth white and breath fresh. Poor oral health may also harm the liver.  

There’s a surprising connection between gum disease and chronic liver conditions, such as cirrhosis and fatty liver disease. Research suggests that something as simple as good dental care of the gums can help protect the liver from disease. 

“The evidence so far suggests that keeping gums healthy could benefit the liver. Doctors and dentists agree that good oral health is essential for the liver as well as the gums and teeth,” said Juan Pablo Arab, M.D., the director of alcohol studies at Virginia Commonwealth University’s Stravitz-Sanyal Institute for Liver Disease and Metabolic Health. “If you brush, floss, and get regular dental checkups – you’ll boost your liver health too.”  

Arab recently published a review of research on this topic in the journal eGastroenterology. He spoke with VCU Health News about the role of oral care in liver health.  

How are gum disease and liver disease connected?   

Chronic liver diseases affect millions of people worldwide. Excessive alcohol consumption, obesity and viral infections like hepatitis are well-documented risk factors. Now, studies point to another, less obvious factor — gum disease.   

Gum, or periodontal, disease is a bacterial infection that causes gum inflammation that, if untreated, can lead to tooth loss. It has already been linked to heart disease and diabetes. Researchers are now exploring its role in liver damage. Studies show that up to 68% of people with cirrhosis have gum disease, a significantly higher percentage than in the general population. 

What causes people with liver disease to develop gum disease too?  

One reason may be that individuals with liver disease often struggle with oral hygiene due to fatigue, medication side effects, or lack of access to dental care. Additionally, liver disease weakens the immune system, making it harder to fight infections, including those in the gums.   

But it’s not just about poor hygiene. It’s also about inflammation. Gum disease triggers chronic inflammation in the body, and scientists believe this ongoing immune response may worsen liver disease by increasing inflammation and scarring in the liver.   

How can bacteria in the mouth affect the liver?  

There are vast amounts of bacteria in our bodies, particularly in the mouth and gut, where they help with digestion and immune function. Scientists think that when oral bacteria from gum disease enter the bloodstream, the bacteria may alter the balance of gut bacteria.   

This imbalance can lead to liver inflammation, which is especially problematic for people with conditions like metabolic dysfunction-associated steatotic liver disease (MASH) or cirrhosis. In both human and animal studies, researchers studying liver tissue have found the bacterium Porphyromonas gingivalis, which is key in gum disease. In some cases, it appears to accelerate liver damage.  

What can happen if you have liver disease and develop gum disease?  

Several studies reinforce the link between poor oral health and worse liver disease outcomes. In a Danish study, nearly half of people with cirrhosis had severe gum disease, compared to only 10-15% of the general population. Other research links severe gum disease to higher infection rates and even increased mortality among cirrhosis patients.   

Another study found that 72% of patients awaiting liver transplants had periodontitis. The more advanced the patients’ liver disease, the worse their oral health. That bodes poorly for their chances for organ transplant.  

Unfortunately, many patients with chronic liver disease do not receive regular dental care, potentially worsening their condition.  

What’s the role of oral care in liver health?   

Given the growing evidence, experts urge people with liver disease to prioritize oral health. Routine dental checkups can help catch gum disease early, preventing it from developing into a more severe infection. Professional cleanings remove plaque and tartar buildup that brushing alone cannot.   

Daily oral hygiene is also crucial. Brushing twice a day with fluoride toothpaste and flossing regularly help control harmful bacteria. Some dentists recommend antibacterial mouthwash for extra protection against plaque and inflammation. Avoiding smoking and limiting alcohol consumption further reduce risks to both oral and liver health.   

Diet also plays a role. A balanced diet rich in vitamins, particularly vitamin C and D, strengthens gums and supports the immune system. Since liver disease weakens the body’s defenses, maintaining good oral hygiene may help reduce complications.   

What else are VCU researchers doing to draw connections between liver and gum disease?   

Researchers are still working to fully understand the connection. Here at VCU, gastroenterologist Jasmohan Bajaj, M.D., has examined the issue for about a decade. He is teaming with periodontists, dentists who specialize in treating bones and tissues around teeth, at the VCU School of Dentistry to study, in part, the barriers for people with cirrhosis to get dental care. Socioeconomic factors, such as education, marital status, income and health literacy, as well as diet and drinking, are known to be correlated with the development of gum disease. 

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