When people hear “microbiome” they usually think of the gut -- that’s where the majority of the 100 trillion or so bacteria in our bodies reside. What’s less appreciated are the other bacterial populations that make sure the body stays up and running, for instance, on the skin and in the genital regions. One of the most intriguing, and most important, bacterial ecosystems is the oral microbiome which really isn’t a single microbiome at all but rather a collection of neighboring bacterial populations, approximately 700 strains in all, that have colonized our gums, tongue, the mucous lining of our cheeks and the surface of our teeth. This is some of the most densely populated bacterial real estate in the body with its primary function being to maintain our oral health – think cavity-free teeth and pink gums resistant to infection and recession. But, as the first stop in the GI tract, it also influences what’s happening further down the line, whether we’re talking cardiovascular and metabolic health or even protection against cancer. Which makes sense -- every time we swallow, we send millions of bacteria from the mouth into the gut. So, here’s what you need to know about your oral microbiome, what is does and how best to take care of it, so it can take care of you for years to come:

What your mouth (and your oral microbiome) is trying to tell you. 

When your mouth isn’t happy, it lets you know. You’re prone to cavities, that is, opportunistic bacteria, feasting on sugars in your mouth, producing acid that eats away at the enamel of your teeth. Or the bacteria can infect the gums that house your teeth, making themselves known in the form of oral ills like periodontal disease, resulting in swelling, bleeding, the loss of gum tissue, and, ultimately, the loss of teeth. Another sign that unfriendly bacteria are creating an unhealthy, acidic environment in your mouth – too much dental plaque, that is, the slimy film that builds up around the teeth and can turn into hard tartar which only your dentist can remove. Want more bacterial troubles? Bad breath, or halitosis. 

Oral bacteria isn’t bad, except when it’s out-of-balance.

For decades, the traditional thinking was that bacteria was behind all these mouth troubles so let’s just get rid of them. That gave rise to harsh detergent-based toothpastes and alcohol-based antiseptic mouthwash, kind of like carpet-bombing the mouth, indiscriminately taking out the good with the bad. Now we appreciate that our job is to maintain a healthy balance between bacterial strains, not letting the opportunistic bugs, often anaerobic strains that don’t require oxygen, overwhelm the protective ones. A lot comes down to good oral hygiene habits – regular brushing and flossing, and regular visits to the dentist for a professional cleaning. I recommend a toothpaste with gentler, more natural ingredients (Tom’s of Maine is a popular brand) and as for conventional mouthwashes, ditch ‘em. Some readers may also want to explore approaches that go beyond the mainstream, for instance, oral probiotics  (typically in drink, lozenge or chewable form) that contain bacterial strains commonly found in the mouth, or tongue flossing, a practice emphasized in the Indian ayurveda healing tradition. 

What starts in the mouth doesn’t necessarily stay in the mouth.

We know that oral bacteria interact with the body below the neck, even if the cause and effect isn’t as pinned down as, let’s say, cavities. But that’s not to say that the effects of oral bacteria running amok doesn’t have far-reaching tentacles because they very much do, and few people realize just what a big deal it can be. In fact, probably the most suggestive evidence concerns heart disease. Turns out, some of the same potentially harmful bacteria show up in both the mouth and the coronary arteries. And it’s reasonable to assume that the inflammation that characterizes periodontal disease may contribute to a similar inflammatory process in the coronary arteries which allows LDL cholesterol to grow into artery-clogging cholesterol plaque. In a number of studies, poor mouth health correlates with poor cardiovascular health. Plaque in the teeth, plaque in the arteries, it’s a bad build-up anyway you look at it. And the oral microbiome connection doesn’t stop at the heart. There’s a correlation between bacteria-driven periodontal disease and diabetes, a two-way connection in fact – each condition makes the other one worse. Other research points to a link between poor oral health and poor pregnancy outcomes while preliminary studies suggest the possibility of correlations between oral health and everything from cognitive health to obesity. A 2020 review examined the links between poor oral health and four types of cancer: pancreatic, colorectal, lung and oral. 

Defend and protect your oral microbiome. 

I should hardly have to say this but smoking is a non-negotiable. Yes, it can kill you by destroying your lungs and triggering countless other life-robbing diseases, but smoking also does a number on the oral microbiome, promoting the growth of nasty bugs at the expense of helpful ones. Need another oral health enemy? Alcohol is another big one, a double whammy in fact, which increases the acidity of the mouth and literally pours in plenty of the extra sugar that those nasty bugs love to feed on. In short, drinking and smoking are the horrible health gifts that keep on giving, so give both a hard pass, always.

Feeding your oral microbiome 

This won’t surprise my regular readers but one of the best ways to safeguard the oral microbiome is through diet -- what you put in your mouth and what you don’t. Low fiber sugary processed foods are what you want to avoid, as we’ve already mentioned. And while you might think that candy, sugar in super-concentrated form, is the worst thing you can consume, believe it or not, crackers are even worse. The sugar content is lower but the cracker remnants stubbornly lodge between your teeth, providing an all-you-can-eat bacterial buffet (gross, but true). Dried fruit isn’t any better. On the plus side of the ledger, non-starchy veggies like the leafy greens are the oral microbiome all-stars. They’re packed with minerals which help your teeth “re-mineralize.” Over time, the bacteria in your mouth eat away at your teeth’s protective enamel coating. And your saliva takes calcium and phosphate from the veggies to build it back up, an ongoing dynamic process. Another bonus, the veggies high in nitrates are great for tamping down acidity of the oral environment, which is good for you – and bad for the bad bugs. As well, foods high in either omega 3 fatty acids (think small, oily fish) or polyphenols (think tea, coffee or cacao nibs) have a powerful antioxidant effect which help counter the inflammatory damage wreaked by gum disease, so dig in and do your oral microbiome a solid on the regular.

Don’t stress your mouth. 

What happens when we’re feeling stressed? Well, a lot of noxious things and one of them is that your mouth produces less saliva. So that built-in delivery system to get those necessary minerals to your teeth works less and less well. One more reason to not let stress get the better of you or heaven forbid, go un-busted. I encourage everyone to get into stress-taming techniques, like daily meditation, frequent yoga sessions, walks in nature, enjoying regular sauna time or a hot bath or shower at the end of a long day. Or, all of the above to make sure you take the edge off as often as you can every day so you can better handle daily stresses and keep your mouth healthier to boot.

A deeper microbiome dive – if you dig data.

So, just what’s up with your mouth? There are ways to learn more. For example, Bristle Health offers a home kit designed for people who want a specific read-out on what’s going on in there. All you need to do is send a saliva sample to the company, and they send you back an analysis of your oral microbiome with an action plan to keep it in great shape – in between dental visits and cleaning and well beyond.