This One Habit Can Significantly Improve Your Gut Health—and It Has Nothing to Do with Diet
This is a powerful reminder that our body really is one connected system!
Reviewed by Dietitian Jessica Ball, M.S., RD
Thanks to a rapidly growing body of research and louder collective conversation, more and more Americans are discovering that what happens in the gut doesn't just stay in the gut.
Science suggests that gut health can impact everything from our immune system and chronic inflammation to our mental health and sleep quality. The relationship goes both ways, too; poor sleep, stress and anxiety, excess inflammation and an infection can do a number on our microbiome (the community of good bacteria that call our guts home), too.
And, thanks to one of our go-to gut-health experts, Will Bulsiewicz, M.D., a Charleston, South Carolina-based gastroenterologist and the author of The Fiber Fueled Cookbook, we now know about a whole other body system that's directly connected to gut health (and it has absolutely nothing to do with fiber or fermented foods): our dirty mouths.
Nope, we're not talking about cursing like a reality TV star in the middle of a fight; we're talking about oral hygiene. Ahead, learn more about why gut health and dental health are so connected. Then brush up on the best practices to take care of your teeth, gums and gut all at once.
How Oral Health Impacts Gut Health
William W. Li, M.D., a Boston-based internal medicine physician and author of Eat to Beat Disease: The New Science of How Your Body Can Heal Itself, sets the scene: "Our gut begins in our mouth. Healthy bacteria also live in our oral cavity, in our gums and on our tongue. This is known as our 'oral microbiome.' That means that a healthy gut begins with good oral health, and how we manage our dental health can influence our overall body health."
This plays out in small and large ways. The microbes that live in our mouths are possibly connected to our risk for developing colon cancer, Bulsiewicz explained in the caption for an Instagram video he shared in January 2023:
"There's a specific bacteria called fusobacterium that has shown up consistently in both colon polyps and colon tumors. Fusobacterium doesn't originate in the gut; it originates in the mouth," Bulsiewicz added, noting that scientists and doctors believe that poor oral health might increase your risk for diseases within the gastrointestinal tract.
Other medical professionals and fans chimed in via the comments to agree: "I have been a dentist for over 20 years and it's NOT that surprising that mouth health is connected with overall body health. In fact the mouth and the colon are both parts of the digestive tract." Another says, "As my osteopath always says 'it's all one tube, everything's connected.'"
One example of how connections occur within that tube: When bad bacteria become overgrown inside the mouth, they can produce harmful byproducts, such as hydrogen sulfide, which can damage the lining of the gut. These bacteria and related byproducts can then enter the bloodstream, potentially impacting distant organs, increasing inflammation and contributing to the progression of certain diseases.
"With gum disease, also known as periodontitis or gingivitis, people experience inflammation and an infection in our gums," explains Whitney DiFoggio, RDH, a Chicago-based registered dental hygienist and the co-founder of Teeth Talk Girl. "This gum-disease bacteria can travel to our gut and affect the balance of bacteria there."
Research backs this up: Bacteria in our mouths have been proven to have the potential to travel to our stomach and intestines, per a study published in March 2019 in the Journal of Oral Microbiology.
"Inflammation can lead to bloating, gas and diarrhea," says Kenneth Brown, M.D., a gastroenterologist in Plano, Texas, and the host of the Gut Check Project podcast. "Poor dental health can lead to tooth decay and gum disease. These conditions can cause chronic inflammation in the mouth, leading to inflammation throughout the body."
Dental health not only correlates with gut health and risk for certain GI cancers. DiFoggio reminds us that research has also shown links between dental health and:
Related: The #1 Tool to Improve Gum and Heart Health, According to Dentists
One common factor among all of those health conditions? You guessed it: inflammation.
How Gut Health Impacts Oral Health
This relationship is bidirectional, according to DiFoggio. The trillions of bacteria in our digestive tract can also impact oral health. If harmful bacteria are able to thrive in what Brown describes as a "disturbed gut environment," an individual may be more likely to build up dental plaque, experience tooth decay and be diagnosed with gum disease.
The inflammation we've been discussing can also start due to an imbalance within the microbiome, and travel up to the mouth and eventually turn into gum disease. If left untreated, this gingivitis can progress into more serious periodontal disease, Brown says.
A healthy gut is also critical for optimal nutrient absorption. Key nutrients, such as calcium and vitamin D—for tooth enamel and bone health—and vitamin A—which aids in saliva production and oral tissue health—are absorbed more efficiently in a healthy gut. If your gut health is compromised, it can lead to malabsorption of these nutrients, impacting your dental health.
Lastly, certain GI diseases can increase risk for some oral health issues.
"Gastroesophageal reflux disease (GERD) can cause stomach acid to enter the mouth, damaging tooth enamel. Inflammatory bowel disease (IBD) has been linked with several oral conditions, including mouth ulcers and infections," Brown adds.
Related: 4 Ways Beyond Brushing to Keep Your Teeth Healthy
9 of the Best Ways to Improve Gut Health and Dental Health at the Same Time
"It's all connected! So maintaining a healthy gut through proper nutrition and gut-friendly practices can contribute to better oral health," DiFoggio says.
A healthy lifestyle that includes a balanced diet, proper oral hygiene and enough quality sleep is the best way to support both your gut and oral health, the experts we spoke to agree. To maintain a healthy gut, gums, teeth and tongue simultaneously, follow these pro tips.
Brush and floss. Brush at least twice per day and floss at least once each day to help remove plaque and food particles and prevent gum disease, which will reduce your chances of oral issues that can affect gut health. "Always confirm with your dental provider that you are in fact brushing correctly," DiFoggio says, and in the meantime, check out her popular how-to video on YouTube. Not so fond of flossing? Try interdental brushes, water flossers or floss picks instead.
Try a tongue scraper. Bacteria can accumulate on your tongue and contribute to oral health issues. Ask your dentist to help teach you how to use a tongue scraper daily to gently remove the bacteria and debris from the surface of your tongue, DiFoggio suggests: "This can promote better oral hygiene and fresher breath!"
Schedule regular checkups. Regular dental checkups and cleanings remove tartar buildup, which cannot be eliminated with regular brushing and flossing alone. Your dental provider can also identify and address any potential issues before they worsen. Shoot for every six months or so for routine maintenance.
Don't be afraid or ashamed to ask for oral health help. If any issues arise between those checkups (such as a chipped tooth or painful, swollen gums), send out an SOS to your dental care team. "It's important to address gum disease promptly through professional treatment. This can help prevent the spread of harmful bacteria and minimize the impact on gut health," DiFoggio says.
Fuel up with a diverse diet. This one will sound familiar if you've been hanging out with us at EatingWell for a bit. "Consuming a diet rich in fruits, vegetables, whole grains, lean proteins and healthy fats provides essential nutrients for both gut and dental health," DiFoggio explains. "A balanced diet helps support a diverse gut microbiota and provides the necessary nutrients for strong teeth and healthy gums." Fruits and veggies earn top marks for the fiber and polyphenols they provide, Brown continues, which can be used by your microbiome to produce anti-inflammatory metabolites for your gut and mouth. Get started with these gut-healthy dinners that can be yours in three steps or less.
Wash wisely. Some prescription mouthwashes contain chemicals that can kill your healthy oral microbiome, which is important for dental health, Li warns. You should be A-OK with most over-the-counter kinds, however: "For the most part, the mouthwash you get at the drugstore is fine and does not harm healthy oral bacteria."
Stay hydrated. Drinking enough water (here's how to estimate your daily ounces) benefits your body in many ways, including supporting gut and oral health. "Water supports digestion, nutrient absorption and bowel function. It also helps to neutralize the acid produced by bacteria that erode tooth enamel and promotes saliva production, which is crucial for oral health," Brown says.
And get some rest. Adequate sleep supports overall health, including your immune function. Brown reminds us that "chronic sleep deprivation upsets your gut microbiome balance, which may lead to oral health problems."
Before bed, try a probiotic. After brushing his teeth before bed, Li takes a chewable probiotic containing Lactobacillus reuteri. Studies have shown that this beneficial bacterium is important for oral health and may even kill some of the harmful bacteria that cause cavities.
The Bottom Line
The health of your mouth and gut are closely linked, Brown says, so taking care of your teeth and gums can help keep your gut healthy—and vice versa. Luckily, many of the best ways to promote oral health and gut health are exactly the same. Aim to eat a well-balanced diet, drink enough H2O, set yourself up for sleep success, schedule regular checkups, and brush, floss and/or tongue scrape as recommended by your dentist.
Once you've finished your pre-bedtime tooth-brushing and popped that probiotic, study up on the 12 foods to improve your gut health overnight so you can plan ahead for a healthier tomorrow.
