The Oral microbiome

your mouth is a window to your overall health.

So, what’s the connection between oral health and general, overall health? Many people are unaware that regardless of how well or often you brush your teeth, your mouth still teems with bacteria — fortunately, most of which is harmless, and maintaining those harmless, even beneficial populations of oral bacteria is key to keeping the more pathogenic variety in check.

Whilst hosting around 700 species of microbiota, the mouth acts as the entry point to your digestive and respiratory tracts, meaning both benign and pathogenic species have the ability to translocate to the gut, the lungs, the sinuses, and even get absorbed into the systemic circulation, impacting the cardiovascular system, a host of other organs, even the brain. Research is showing when pathogenic species move into other niches of the body, they can both cause and increase risk of disease.

Normally our natural immune defences and good oral health care, keep bacteria under control. However, use of certain medications can upset the balance of this ecosystem, (decongestants, antihistamines, painkillers, diuretics and antidepressants). One of the ways imbalance occurs is through reducing saliva flow. Saliva plays a key role neutralising the acids produced by bacteria in the mouth. It also helps to flush away microbes that might otherwise multiply and lead to disease. Another downstream imbalance can occur where metabolic diseases, such as diabetes, lower the body’s resistance to infection, making the consequences of oral health problems more severe.

So, your oral health is probably more important than you realise, your mouth is literally a window to your overall health.

Saliva testing the oral microbiome

Recent advances in qPCR techniques have made it possible to identify and quantify the composition of the human microbiota, in its various niche habitats. Stool testing to assess gut health is now fairly common practice, but few are aware that the oral microbiome can also be assessed. ‘Oral EcologiX‘ by Invivo Healthcare is an easy, do at home saliva test, to assess your oral microbiome, see link below. The mouth alone comprises several distinct bacterial habitats: the tongue, the tonsils, the hard and soft palette, the cheeks and the gums, particularly the gum/teeth margins.

So why might you want to know more detail?

Of the myriad species residing in the mouth, some are useful, bestowing health, whereas other more pathogenic ones have been strongly associated with common, chronic inflammatory diseases. Most people have heard of Periodontal disease in the mouth, but research now shows stroke; cardiovascular and arterial disease; endocarditis (an infection of the inner lining of the heart chambers or valves); certain oral, oesophageal & colon cancers; diabetes; Rheumatoid arthritis; pneumonia; Alzheimer’s; liver disease; even pre-term delivery and low birth weight, have all shown a connection to oral bacteria.

Recent studies have shown that certain pathogenic strains of oral bacteria that colonise the tissue just beyond the throat, increase risk of oesophageal cancer. Such pathogenic strains that translocate even further – to the gut – can lead to IBS, activation of the intestinal immune system and produce chronic inflammation.  P.gingivalis is an oral bacterium that causes periodontal disease and if chronically elevated in the gut can increase risk of colon cancer, inflammatory bowel disease and diabetes.

The bi-directional relationship between diabetes and periodontitis is well established. Oral investigations in diabetic patients have shown they also have significantly increased levels of Capnocytophaga and Tannerellla forsythia, in addition to P.gingivalis. (All three bacteria are tested for in Oral EcologiX – see below). The answer to re-establishing a healthy oral microbiome is most definitely not commercial, antibacterial mouthwash.  These in fact disrupt the balance of a healthy microbiota, indiscriminately killing off the favourable, commensal species, whilst often allowing hardier pathogens to flourish, with less competition around them.

There is a relationship between the routine use of mouthwash and risk of type 2 diabetes.

The now well established relationship between periodontal disease and diabetes has prompted scientists to take a closer look at oral bacteria and cardiovascular disease, because Stroke and heart disease are the main causes of death in diabetic patients. Evidence of translocation into systemic circulation has been confirmed with oral bacteria being identified in the blood clots of stroke victims.  It should be emphasised at this juncture that the presence of these bacteria flags up ‘increased risk of’ these conditions, not necessarily the presence of overt pathology.

However, identifying said risk, enables the holder of the information to embark on preventative protocols.

Twelve relevant species can be identified using a simple PCR saliva test from INVIVO Healthcare (cost: £149.00)

https://invivohealthcare.com/products/testing/oral-ecologix/ 

I decided to write this piece following a client’s experience, who generously shared their ‘Oral EcologiX‘ results, and did so in part because their oral hygiene practices – deemed exemplary by their dentist – had none-the-less failed to prevent significant colonisation of four pathogenic species (and four others reported as slightly elevated), which after researching both the literature and Invivo’s interpretative guide, in summary suggested an elevated risk for: aggressive periodontal disease; potential infections beyond the oral cavity (endocarditis, urinary tract, spondylodiscitis); atherosclerotic plaques; oesophageal cancer; with a milder risk for pre-term labour; and pelvic inflammatory disease.

Again, it’s worth reiterating that the presence of these species pointed to an elevated risk for, not necessarily the existence of overt pathology, however my client was relieved that ‘P. gingivalis’ was not one of the strains identified in their result, as a growing body of evidence now links this bacteria, found in Amyloid plaques, to Alzheimer’s, which runs in their family.

Armed with this information it motivates one to consider in more detail how one might improve oral hygiene, and how one might embark on a restorative program to nudge the mouth’s ecology back towards a more healthy, balanced one, where commensal species flourish and keep opportunistic pathogens at bay.

Step ONE: remove from your bathroom those commercial, antibacterial mouthwashes. We need to protect and encourage the presence of the good microbes to out-compete the presence of the bad ones.

Step TWO: Book in to my clinic to organise your own Oral Ecologix saliva test, with the goal of using the results to kick-start a restorative protocol, to nudge your oral microbiome towards a healthier homeostasis.

Take responsibility, with

 Preventative Functional Medicine

NB: This blog article does not constitute medical advice, it is for information purposes only, do NOT discontinue the use of medications prescribed by your doctor, without further consultation.  

References:

Olli Patrakka et al., (2019) Oral Bacterial Signatures in Cerebral Thrombi of Patients With Acute Ischemic Stroke Treated With Thrombectomy. J of the American Heart Assoc., 8:e012330

Muszynski D et al., (2022) REVIEW article: Esophageal cancer and bacterial part of gut microbiota – A multidisciplinary point of view. Front. Cell. Infect. Microbiol., Vol 12

Maoyang Lu st al., (2018) Oral microbiota: A new view of body health. Food Science & Human Wellness Vol 8(1): 8-15