Ah, the dreaded dentist visit. We all know we have to go every six months, and at the end we all get the same friendly advice, “Make sure to floss!” And while I’ve always been a pretty consistent flosser, I didn’t know how important it was until I started researching the second most diverse microbiome in the body: the oral microbiome. And as a medical doctor who helps my patients tend to their gut microbiomes almost daily, I was fascinated by the huge role the oral microbiome (and flossing!) plays in our overall health.
When you really think about it, it makes sense that our oral cavity houses a very special ecosystem. Our mouths are, after all, where digestion actually begins—not to mention, they are the primary entrance to the rest of our body, where we do a lot of interacting with the outside world. Scientists have been turning their attention to this special community of mouth organisms for decades. In fact, a book published in 1890, The Micro-organisms of the Human Mouth, promoted our current habits of brushing and flossing.
So what’s so special about our oral microbiota? The bugs in our mouth form biofilms, which is a fancy word used to describe complex groups of microorganisms. You may have heard of plaque, which is essentially a multi-organism biofilm layer on the surface of the teeth. If these growing plaques are not detached, it can lead to dysbiosis, allowing disease-promoting bugs to take hold and cause issues like cavities, gingivitis, and periodontitis (the most severe form of gum disease that eats away at both the gums and teeth). Even more importantly, oral dysbiosis has a reach far beyond the mouth. These oral microbes do make their way to the rest of the digestive tract—and actually, there is a 45 percent overlap in species seen in the oral and fecal microbiota.
Aside from the gut, these oral bad bugs can gain access to the rest of the body by going through our mouth membranes and periodontal pockets (separations between the gums and the teeth) and entering the bloodstream. When this occurs, the immune response can be altered, inflammatory pathways can be activated, and disease can occur at a site far, far away from the mouth. Periodontal disease has actually been linked to both diabetes and cardiovascular disease. How in the world does that happen? The bacteria of periodontal disease produce lipopolysaccharide (LPS), which changes the body’s control of sugar levels and contributes to atherothrombogenesis (a big term to describe an accumulation of plaque and clotting factors in the heart arteries). Periodontal bacteria’s DNA has even been found in the coronary artery plaques of those who suffered a heart attack.
