Can a Dysbiotic Mouth Contribute to Transmission of Noncommunicable Diseases?

Written by: Sara Treffert


Healf Journal

Wait, isn’t noncommunicable also non transmissible? Whilst noncommunicable diseases (NCDs) are often considered chronic and non transmissible, a favourite topics, gut health and more specifically oral health, may just challenge this theory.

What is a Noncommunicable Disease?

An NCD is described by the World Health Organization , as a chronic disease that cannot be transferred between people or other organisms. NCDs include conditions such as cardiovascular disease (CVD), cancers, rheumatoid arthritis (RA), dementia, Alzheimer’s, irritable bowel syndrome (IBS), and type 2 diabetes. Interestingly enough tooth decay is the #1 disease worldwide and is also considered an NCD…

But what if these conditions mentioned often have an oral dysbiosis link? Can dysbiotic oral microbes hitch a ride to other parts of the body wreaking chronic havoc on our systems and ultimately be a potential contributing cause of so-called noncommunicable disease? Science says yes .

A Bidirectional Relationship Between Oral Health and Chronic Diseases 

Chronic disease connection to oral infections may seem like a new scientific discovery, but it was documented in 1891 in The Lancet by the first oral microbiologist. Given this is still not widely recognized in the conventional medicine space, it is no surprise that this novel theory was not welcomed at the time.

Fast forward to modern day, research is clear that oral dysbiosis, which includes conditions like periodontal disease (PD), gingivitis (bleeding inflamed gums), halitosis (bad breath), decay (carries or cavities) etc., can all be associated with, and may, in some cases even be an independent risk factor for certain NCDs. 

Could Your Oral Health Status be a Driving Factor in Your Chronic Disease? 

  • Cardiovascular Disease : A 27-year, 755 subject study at the University of Helsinki concluded that “oral infections were an independent risk factor for subclinical atherosclerosis.” A 2017 study found that periodontal disease is a “contributory cause of atherosclerosis.”

  • Alzheimer’s : Recent studies show a 70% increased risk in population age 65+ when PD was present.

  • Metabolic Dysfunction/Type 2 Diabetes : Those with type 2 diabetes have a 3x greater risk of developing periodontitis . This alarming connection is also bidirectional!

  • Liver Cirrhosis : 54% of the problematic bacterial species in liver cirrhosis originate in the mouth.

  • Irritable Bowel Disease : Multiple studies have found that the oral flora of IBD patients are significantly different [with dysbiotic levels] from that of healthy people.

These are just to demonstrate a few examples of extremely common NCDs that have a clear pathophysiology connection when oral dysbiosis is present. Dr. Burhenne from Ask the Dentist recently shared on MindbodyGreen’s podcast that it is estimated ~70% of chronic diseases have some involvement with an oral bug.

What Bugs Our Mouth and Body?

Most organisms in the mouth are healthy…until they are not. Meaning when opportunistic oral inhabitants such as P. intermedia, S. mutans, F. nucleatum, P. gingivalis, candida (albicans), and aspergillosis, become out of balance, they all have the ability to contribute to the aforementioned chronic NCDs. For a visual illustration of the connections, this is a great figure . While oral health is imperative for overall health, always keep in mind that chronic disease, more often than not, is multifactorial.

Bad Bugs AND Poor Oral Hygiene Set the Environment for Oral Infection

Unfortunately, with dental decay being the #1 disease worldwide and a clear connection between oral dysbiosis and systemic diseases, we also have to take into consideration those we interact most with, including housemates, pets, colleagues, etc.

Often, the most interaction is between partners where an intimate kiss of 10 seconds transfers approximately 80 million  bacteria. Sorry to say, you don’t get to decide which microbes transfer! There is also a direct correlation between poor oral health status of primary caregivers and childhood carries incidences as there is frequent close contact, sharing of drinks, utensils, etc. Your oral health doesn’t just affect you. 

Before this sends anyone into a tailspin and refuses affection from their loving mum or nan (which I absolutely do not advocate for!) because she has tooth decay and/or a chronic disease, there are many points to consider. To be clear, a dysbiotic mouth does not mean transmission of disease to others. And mainly, that if you are a healthy host with a healthy mouth, chronic disease is extremely rare. How is that for empowering?

Additionally, as we progress into adolescent years and beyond, our oral microbiome tend to stabilize. The oral microbiome makes up 22% of our bodies’ total microbes, the second most populated area behind the gut. It also one of the most diverse and stable microbiotas in the body with more than 750+ strains identified .

Building Resilience: Our Daily Homework

Research demonstrates we have at least 10x more microbes in us than human cells; we need microbes to survive. But we have to provide a desirable environment for health-supportive ones to thrive appropriately. So when these populations are negatively disrupted, it is no surprise that it can lead to various health issues. The good news is we can take significant control of our chronic disease susceptibility just by keeping our friendly microbes in our mouths and throughout our bodies happy. It’s about the context and building immune resiliency:

  • Remove what harms our good microbes; especially chemically laden ultra-processed foods.

  • Eat seasonally and increase variety/diversity of whole foods. This should include fermented and pre-pro-and-postbiotic rich foods. You can also supplement if and when needed.

  • Switch to non-toxic personal & oral care products . No more regular use of antibacterial mouthwash and hand sanitizer (except in necessary situations). We wouldn’t take antibiotics every day, so why pose a constant assault on our body’s first line of defense—the mouth and skin?

  • Proper oral hygiene routine: tongue scrape, floss, and brush daily, especially at night (this is a great podcast from Dr. Huberman).

  • Have regular dental cleanings and evaluation.

  • PSA: Close the toilet lid before flushing! These organisms can be propelled 1.5+ meters and into the HVAC (ventilation) system. This is not where you want to be ‘sharing’ or ‘accumulating’ organisms from. Modern waste sanitation has drastically improved human health for a reason.

Takeaway: Embracing Microbes for Health

More than ever, it’s important to focus on what you CAN control, not what you can’t. Whether you like it or not, someone else’s hygiene is their choice, let’s just hope they make good ones! We all get one home called our bodies; treat it with respect, ultimately your health is your responsibility. Most importantly, we build long-term resilience by interacting daily with those we enjoy being around and being in nature. Community, including our microbes, matter most!


This article is for informational purposes only, even if and regardless of whether it features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice. The views expressed in this article are the views of the expert and do not necessarily represent the views of Healf