The Oral Microbiome: Why Your Mouth Matters for Whole-Body Health

How oral bacteria influence localised and systemic health

Photo by Cedric Fauntleroy

Did you know that the oral cavity houses the second largest and most diverse microbiome in the human body, second only to the gut?

A healthy oral microbiome relies on the formation of healthy bacterial, fungal, and viral colonies. And just as our gut microbiome can become ‘dysbiotic’ – or imbalanced – so can the ecosystem in our oral cavity. When these microorganisms become embedded within a sticky biofilm on the surface of the teeth, or above or below the gum line, they form into what we know as plaque, which can be caused by poor oral hygiene.

The accumulation of plaque encourages the growth of less favourable and disease-associated bacteria, that can cause damage locally to our gums and may lead to oral diseases such as gingivitis, periodontitis and tooth decay.

Research is showing us that oral dysbiosis and inflammation may also be a driver for systemic diseases such as dementia, cardiovascular disease (1), arthritis, and autoimmunity, via the translocation to the gut or through the bloodstream.

Porphyromonas gingivalis is a keystone pathogen of the mouth, and if found, even in low numbers, has the ability to manipulate the entire oral microbiome. Studies have shown that it can evade the immune system and release toxic enzymes that degrade the collagen in gums, leading to pocket formation and bone loss (2). Furthermore, P. gingivalis is stomach acid-resistant, so it can easily the colonise the gut microbiome, causing increased intestinal permeability (or “leaky gut”) and systemic inflammation throughout the body (3).

Streptococcus mutans is another key pathogenic species associated with dental caries and known to form biofilms. Some studies have looked at the use of Lactobacillus spp. and Bifidobacterium spp. for the prevention of dental caries (4).

Localised inflammation

An imbalanced oral microbiome can lead to localised oral diseases such as gingivitis, periodontal disease, halitosis, tooth decay and cavities. It is important to protect the dentin of the teeth (a calcified tissue that forms the main part of the teeth), to prevent further decay and damage, and help prevent translocation of pathogens into the bloodstream.

Systemic impacts of oral dysbiosis

As mentioned, oral dysbiosis can be a driver for systemic diseases such as dementia and Alzheimer’s, cardiovascular disease, metabolic disease, arthritis, and rheumatoid arthritis, when the bacteria translocate to the gut or through the bloodstream. It’s even been associated with pregnancy outcomes such as premature birth, pre-eclampsia, and miscarriage.

What can we do?

Good dental hygiene is imperative, especially keeping on track with your dentist appointments, dental hygienist, and a thorough daily oral care routine.

Physical removal of dental plaque biofilms is an effective treatment, and why routine dental visits are essential.

Other recommendations include:

🌿 Maintaining a healthy balanced diet – include a wide diversity of plant foods - prebiotic fibres, polyphenols, healthy fats, fat-soluble vitamins such as A, D, E and K, minerals such as calcium and magnesium, and reduce or avoid processed carbohydrates, trans fats and sugar.

🌿 Avoid snacking, ultra-processed foods, sugar and refined carbohydrates. Snacking can lead to worsening decay and bacterial dysbiosis. If snacks are needed, opt for fresh fruit and nuts or other whole foods.

🌿Ensuring adequate dietary calcium is crucial for maintaining tooth enamel. Good sources of calcium include beans and lentils, leafy green vegetables, nuts and seeds (especially sesame seeds and tahini), organic tofu, seafood (especially sardines) and organic full fat dairy.

🌿 Include fermented foods such as kimchi, sauerkraut, yoghurt, miso, and kefir.

🌿Practice good dental hygiene - brushing your teeth twice a day and using floss and/or interdental brushes.

🌿 Oil pulling (5), or probiotic mouthwashes can be helpful.

🌿 Avoid smoking as it severely disrupts homeostasis of the oral microbiome; it is best avoided. It can also be a causative agent of oral cancer (6). 

Several human trials have shown that a combination of specific strains of probiotics such as Lactobacillus helveticus Rosell-52, Lactobacillus rhamnosus Rosell-11, Bifidobacterium longum Rosell-175 (Trademarked by Activated Probiotics), with Saccharomyces boulardii (CNCM I-1079) have been found to reduce the accumulation of dental plaque and gum inflammation, thereby inhibiting dysbiosis, halitosis, and oral thrush. Furthermore, they have been shown to reduce periodontitis outcomes.

*It is important to note that probiotics are not suitable for everyone and are contraindicated in certain medical conditions, including for patients who are immunocompromised; or with pancreatitis; short bowel syndrome; with open wounds after major surgery; in intensive care units, or with malaena (dark blood in stools).

If you are concerned about your oral health, you might want to consider oral microbiome testing. It is recommended to discuss the options with your practitioner.

Need Personalised Support?

As a Registered Nutritional Therapist, specialising in gut health, I help clients identify the root causes of digestive issues, hormone imbalances, autoimmune diseases, and other chronic health issues, and create tailored nutrition plans that help to restore balance.

Book a free 15-minute discovery call to explore how I can support your journey to better gut health.

Or download my Free Healthy Gut resources to get started today.

Order your copy of The Simple Gut Reset Cookbook  for more gut-supporting recipes.

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