Environmental and Ecological Oral Health


Environmental Oral Hygiene – A Sustainable Approach to Whole Dental Health – Introduction and Intention

It is Monday, 6th April here in New Zealand, and the world has changed and is now a different place. The roads are quieter, the streets are empty, less the occasional dog walker and jogger, and the lockdown is solidly in place. A peculiar sense of calm is reinforced by the bird song outside, the environment and habitat seemingly swelling to fill the void of lost modernity. The natural world appears to be benefitting from the lack of human activity too, far fewer cars and planes travelling the streets and airlanes, fewer emissions and, thankfully, less pollution also. The deadly epicentres of the COVID 19 impact, Italy, Spain, Wuhan and New York are experiencing significant improvements of air quality and, strangely too, wild animals, in some places, are seen visiting empty neighbours, once teeming with people.

This novel  COVID 19 experience, from my own particular professional perspective, has created an eerily ideal learning opportunity.  It has presented the opportunity and time to complete a project I began over a year ago finally presents itself. In turn, I will reflect upon it and consider my options and choices regarding whether the economic and financial fallout post-COVID 19 allows me to return to my clinical normality, perhaps.

The project, called Whole Dental Health, began as an idea to implement professional development as part of a nine-week career break between jobs and places. The journey, I called it an odyssey, some might have classed it as a sabbatical, took me to France, the UK and the States. It was a moment in time to test previous learning, undertaken in an action research model of new knowledge creation. It allowed me the space to open up the subject matter, a follow on from the odyssey, where I felt the need to fill knowledge gaps in my present clinical headspace. I had reams of paper, stapled into studies, gathering dust over the months since they were printed, awaiting this moment. I had no excuse and every cause to venture into them. How would I approach the creation of meaning from all of this information? What would be my approach? The action research model would remain, but I also wanted not to feel too restricted by an overtly academic model. I wanted it to feel real, to me, to be an honest and authentic record of the journey.

The choice of a storytelling approach to the project is anathematic of authentic learning and action research. It is particularly indicated with explaining a process or a journey reflectively, where you guide your own learning based upon where you feel you have a need to improve or create new knowledge in particular subjects or matters within your workplace. You become the self-directed learner, you empower your quest for it through a guided process, it being authentic and genuine as it is explicitly applicable to you. Your research, critically appraises, creates and designs ways in which you can test its validity, reflect upon those outcomes, change, implement or reset the parameters or if unsuccessful, try again in a different way. Creating new knowledge, in an open-ended and critical way maybe seem by others in written words, like this, published and disseminated through social media platforms or presented to a professional audience of some kind. Both are a form of peer review and can be, by our colleagues, challenged, adopted or adapted for their own practice to the benefit of their clients.

Ironically, in this time of great global upheaval and change, comes to the New Zealand Dental Healthcare profession change as well. This brave new learning world has the potential to seriously test and challenge the will, intentions and adaptability of all concerned. Traditional continuing professional development (CPD) regulated, via The New Zealand Dental Council (NZDC), in verifiable and non-verifiable formats were expressly set numbers of hours had to be completed, demonstrated through a portfolio of evidence if required by the council as part of an audit. These audits, conducted on about ten per cent of the re-registering dental body every CPD cycle, I feel, made the need to meet the expected numbers higher than achieve appropriate learning, essentially detracting from the real need for authentic, individual education. So I was to my great surprise and delight that several weeks ago the NZDC announced the intention to restructure its current CPD cycle. In will come, as from next March, the new paradigm incorporating the creation of a Professional Learning Plan (PDP), designed Professional Learning Activities (PDA) and a formal personal peer relationship with some you can nominate yourself. The most exciting part of the new direction, however, was the need to undertake written reflection on the learning outcomes from PDA’s you have proposed and made through you PDP, and this in turn, discussed with your peer reviewer and validated as such via an online portal.

The thought that hundreds of dental healthcare professionals undertaking work-related, personally guided and relevant learning with the intent to write it up and it be reviewed may sound quite revolutionary to some, complicated and unnecessary to others. However, it needs to be borne in mind this process is already done by many, especially clinical nurses, midwives and other allied healthcare workers. What this does demonstrate, in my humble opinion, however, is that the New Zealand dental profession is finally catching up with allied healthcare professionals too and that the good old days of mathematical calculations for gaining re-registration has gone. There is no need for the numbers game anymore, just, I hope, the intention to gain quality self-directed education. It is now time for it to be appropriate to one’s workplace and associated practise, to authentically apply it into practice. Additional reflection, a new skill to learn for some, upon its process, perhaps modify or adapt this new knowledge creation, guided with peer support and review. The need for the dental trade industry to get its grubby pores into it will hopefully diminish and, if continued, be more relevant to the clinical spaces of practices and not for cynical influence and gain.

So, finally, over the next few weeks expect posts related to authentic learning and action research, future professional development, oral health, related to systemic and metabolic health, diet and nutrition-related to dental caries and periodontal diseases, the oral microbiome, fluoridation, saliva and pH, alternative antimicrobials ( in particular honey ), sustainability and the creation of a philosophy related to those.


Joellen Coates – University of Wyoming – Honours Thesis – “Got Teeth? How the Oral Microbiome and Diet Affects our Oral Health and the Future of Dentistry.” Aligned with Whole Dental Health? A Reflection.

“The roots of education are bitter, but the fruit is sweet”. Aristotle

When I began the initial research phase for part 2, I pondered the possibility that the subject matter about the aims and goals of Whole Dental Health and the principles I want to pursue professionally here in Nelson had already been published! I came up this nugget of theological gold courtesy of Joellen Coates, a thirty-plus page of her Honours Capstone Project. This is undertaken in the final year of tertiary learning by some educational establishments. It is a unique and very personal and self-directed process by which the individual learner can develop a thesis, develop and establish new knowledge, test it and formulate a learning premise that ultimately goes towards the final grade and graduation. 1, 2 Her thesis looks closely at the human oral microbiome, its constituent parts, it’s history, present and potential future in regards to unlocking its potential to impact the direction of oral health in the future by understanding its very nature better.

She sets the historical context, beginning with hunter-gatherers, then progressing into the Neolithic Period when Palaeolithic man moved from a seasonal and mobile dietary life into an agricultural. This was when the Neolithic people stayed landlocked within the confines of the cereal sown and cattle raised, nearly starting about ten thousand years ago. With this change in dietary lifestyle comes a shift in dietary, behavioural changes. This brings on oral microbial changes leading to dysbiotic changes to oral flora.  This is demonstrated by increasing archaeological evidence of increasing dental diseases, namely caries and periodontitis.

“For the first half of geological time, our ancestors were bacteria”. Richard Dawkins

The several hundred or so bacterial species of our oral microbiome combine with other microorganisms such as fungi, viruses, archaea and protozoa to construct our complex and diverse ecological communities. They have done so from days in memorial. In healthy subjects, they display great diversity and health benefits. It begins before birth with some early pioneering bacterial species culturing the unborn mouth via the umbilical cord, amniotic fluid onward into the developing foetus. During delivery, more significant seeding is initiated by contacting the mother’s vaginal microbiome and contact with their skin, being further reinforced through breastfeeding and so on and so forth throughout life. The development of a functional and balanced oral microbiome has begun. How this community of diverse microorganisms can afford dental and general health benefits is the subject of modern research and, more so, how its disturbance can lead to a host of dental diseases is the subject of my interest.

“The important thing is not to stop questioning. Curiosity has its own reason for existence”. Albert Einstein

Within ancient dental calculus holds the clues and answers within highly preserved bacterial types, their cellular components and DNA. Careful analysis reveals that Neolithic farmers saw a significant increase in the consumption of fermentable carbohydrates as opposed to their cave-dwelling ancestors, in this case, the higher consumption of cereals, such as we do today.  Studies demonstrate that modern microbiomes are “less diverse compared to ancient samples and could be composed of more opportunistic cariogenic bacteria”. Conversely Pre – Neolithic populations were rarely affected by dental diseases. 3

Baumgartner and co-workers in 2009 designed a simple study that took Swiss students from a modern Swiss diet.  For a month, subjects ate a Stone Age type diet to determine the effects of a lack of modern oral hygiene on the oral microbiome and the presence of gingivitis. The results indicated a change and growth in the oral microbiome.  Less pathogenic bacteria were present, and a significant decrease in the signs and symptoms of gingivitis was observed. This simple and less rigorous research brings up many further questions as well as a need for more detail regarding its process. The next paragraph will look a little deeper into it.

The sample size was small, ten subjects, in one group and the study length was just four weeks. Microbiological samples were collected at the mesiobuccal aspects of all teeth and from the dorsum of the tongue. All ten subjects had no periodontitis. The results from samples gathered after four weeks demonstrated mean bleeding on probing decreased from 34.8% to 12.6%, plaque scores increased from 0.68 to 1.47. Periodontal depths also showed changes which decreased at sites of sampling by 0.2mm. All three measured a P-value of <0.001, indicating that the results have less than one in a thousand chance of being wrong. The bacterial profiles had a higher growth count for 24 of 74 species despite the reduction of pathogenicity.

The elimination of refined sugars decreased the risk of gingivitis in the absence of traditional oral hygiene methods, despite the increase in plaque levels. This demonstrates that beneficial and symbiotic bacteria thrived in the oral microbiome in the subjects tested over four weeks without the benefit of oral hygiene or the consumption of a modern style Swiss diet. 4

The oral microbiome is continuously exposed to the elements and pressures of the external environment and needs to treated, in the same way, as a precious ecosystem. The oral microbiome utilises nutrition supplied from the hosts’ diet, their saliva flow, enzymes and minerals. It is ecological disruption, and dysbiosis can stem from reduced saliva flow rates, quantity and quality, illness, stress, poor diets and even genetics.

“Is your diet really nutrient-dense”? Dr Weston A. Price

Importantly, dietary changes since hunter-gatherers have dramatically changed. The simple food staples they once gathered have become processed, starting in Neolithic through to the modern, Industrial Periods. These have fundamentally altered seven crucial nutritional characteristics of our old ancestral dietary habits. These include glycaemic load, fatty acid composition, macronutrient composition and micronutrient density, acid balance, sodium-potassium ratio and fibre content. Glycaemic loading, fatty acids (Omega 3’s), acid balance and macro and micronutrient contents will, in particular, prove crucial regarding the oral-systemic interface of dental health and development. The controversial works and research of Weston A Price will need further examination in a quest for higher knowledge and connection to modern-day alternative lifestyle and medical cultural ideology and practice. 5

The future of dentistry concerning the oral microbiome, let along with everything that appears to be happening in the world right now, is ripe for discovery. The benefits of a balanced, beneficial and healthy oral microbiome and, in turn, how we decide to directly or indirectly affect and influence it to our dental and general health benefit requires our attention. Poor nutritionally based diets, with emphasis on the consumption of processed rich foods, in particular fermentable carbohydrates, promote less diversity and imbalance of our oral ecology. This must become an innate message to our clients who suffer from dental diseases, no matter how mild or severe they present.

“Natural ecosystems regulate themselves through diversity.” Big Little Farm

Finally, what we think, or are led to believe, helps us control and manage oral health issues may actually be more in the way we chose to live and eat and less that comes out of a tube or bottle. The stresses and pressures in our everyday lives, the foods we chose to consume and the ability to manage not only our daily oral hygiene habits effectively but how we sustain and maintain the diversity and symbiosis of our oral microbiome as a whole is vital.


  1. Coates J, 2017. Got Teeth? How the Oral Microbiome and Diet Affects Our Oral Health and the Future of Dentistry.
  2. Capstone Project. https://youtu.be/CWxwwLP2THU
  3. Alder CJ et al., 2013. Sequencing ancient calcified dental plaque shows changes in oral microbiota with dietary shifts of the Neolithic and Industrial revolutions.
  4. Baumgartner S et al., 2009. The impact of the Stone Age diet on gingival conditions in the absence of oral hygiene. https://www.ncbi.nlm.nih.gov/pubmed/19405829
  5. Cordain, L et al., 2005. Origins and evolution of the Western Diet: health implications for the 21st Century. https://www.ncbi.nlm.nih.gov/pubmed/15699220

The Oral, Systemic and Metabolic links to Whole Dental Health. A Personal Journey and Overview

When I first qualified as a Dental Hygienist in 1988 the thing that gave me to most clinical trepidation was treating Periodontal Disease (PD), despite my training. I can recall my very first case as a green “rookie” hygienist they were young, a heavy smoker with established disease which was active and unstable. I did my best instrumently, following my training, and when I reviewed them, a few weeks later the resolution and repair I witnessed was astonishing. I felt quite proud of my efforts but was crestfallen to learn they had had a prescription for antibiotics for a separate health condition in the meantime. My dentist gently alluded me to the fact that my treatment alone probably wasn’t entirely responsible for the startling outcome. It became very apparent to me that the systemic benefits of medicine had enhanced the patients host response and had significantly aided his dental disease recovery. This systemic “assistance” made me reflect at quite an early stage of my career, in the complexity and ingenuity of the immune system.

Globally, PD is the sixth most prevalent disease affecting over 11% of the world, rising by 57.3% from 1990 to 2010 1. Periodontitis is a major cause of tooth loss in adults, in particular the aging population and vulnerable sections of society 2, 3, 4. The New Zealand population study, undertaken in Dunedin, indicated that untreated adult gum disease in adulthood is associated with negative childhood low economic status 5. PD is classed as a Non-Communicable Disease (NCD) and shares social determinants and risk factors with other NCDs that cause about two-thirds of causes of death such as heart disease, diabetes, cancer, as well as, more topically, respiratory related diseases 5.There is a growing body of evidence that the effects of PD reach beyond the oral cavity with bacteria and associated inflammatory by-products systemically travel from the point of origin to other parts of the body, helping, over time, to initiate various NCDs. The loss of teeth due to the PD process affects mastication, likely changing dietary habits as a consequence to a more sugar and fat based diet and less fruit and vegetables. In turn this has the potential to increase the systemic inflammatory burden further by increasing the degree of PD, tooth decay, and possibly increasing further risk of NCDs 6.

The mouth has often been described as “the window to general health” with oral systemic health, of late, being seen as the connection the oral cavity and health with overall health. The mouth hosts a unique population of microorganisms numbering between 500 -700 7. The quality of individual oral hygiene significantly impacts how they organise themselves culturally and ecologically, with better maintenance allowing beneficial varieties to thrive and dominate. This is balanced by products found in the oral cavity being regularly bathed by a complex of components from saliva and, from between the tooth and gum, crevicular fluid, both playing an important natural role, mediating and balancing the oral environment 8, 9.

Much research has investigated the relationship between PD and cardiovascular disease (CVD) and has proven diverse and varied 10, 11. CVD is amongst the most common medical problems globally, being responsible for the 33% of deaths in New Zealand and 30% in the USA 12, 13. Oral inflammation, from gingivitis, opens the systemic pathway for pathogenic bacteria to travel to blood vessels elsewhere in the body where they can cause inflammation and damage to arterial walls. The remnants of oral bacteria can be found within atherosclerotic blood vessels far from its origin in the mouth. An alternative theory is that the body’s inflammatory immune response sets off a cascade of vascular damage throughout the body, including the heart and brain. They may also be no direct connection between CVD and PD, and the process maybe mediated through other factors like smoking, negative lifestyle choices, genetics and poor nutrition 14. A large cohort study in 2018 observed nearly 1 million people in Korea of a variety of ages from 30. The conclusion demonstrated the relationship between poor oral health and coronary heart disease risk was confounded by smoking, making causation indeterminable 15.

Pulmonary diseases like pneumonia, chronic obstructive pulmonary diseases and chronic bronchitis bring bacteria from the mouth via the oropharynx into the respiratory tract 14. The immune-compromised who are critically ill and intubated are at risk from bacteria seeding of the lower respiratory tract. Multiple intervention studies have shown that improving the oral hygiene of ventilated cases decreased the risk of ventilator associated pneumonia 16, 17. Aligned with this, evidence that poor dental health is causal in such conditions is at present inconclusive, where institutionalised and ventilated patients are at high risk, those with improved oral hygiene has indicated a positive outcome to their systemic health 18. This research requires careful consideration and appropriate action regarding oral health messages given to institutions nursing and treating risk populations during flu outbreaks and the present COVID 19 global epidemic.

Diabetes is a disease of disrupted glycaemic control resulting from a lack of insulin (type 1) or systemic insulin resistance (type 2)19. Their share a bidirectional association with PD. It negatively impacts oral health but also, conversely, glycaemic control and those affected with diabetes can be up to three times a greater risk of PD than those who aren’t. Those who have well controlled diabetes comparatively have no increased risk 20, 21.

Obesity is a chronic disease affecting 42.8% of middle-age adults, is closely related to several other chronic diseases, including heart disease, hypertension, type 2 diabetes, sleep apnoea, certain cancers, joint diseases, and more. Obesity is defined as excessive body fat in proportion to lean body mass, to the extent that health is impaired. It is associated with chronic low grade inflammation and both local and system oxidative stress, in which it links to PD in oral health 22. Clinical PD studies reveal significant correlations with body mass indices, insulin and lipid levels and oxidative stress markers 23.

Our systemic health can be measured, in part, by looking more closely and specifically at metabolic risk factors that includes obesity, insulin resistance, hypertension and dyslipidaemia. If these factors are dysfunctional, it is termed as Metabolic Syndrome (MetS) and is often characterized by oxidative stress, a condition in which an imbalance results between the production and activation of reactive oxygen species. MetS is thought to play a major role in the pathogenesis of a variety of human diseases, including atherosclerosis, diabetes, hypertension, aging, Alzheimer’s disease, kidney disease and cancer 24. MetS allows the a pro-oxidative state in periodontal tissue, altering antioxidant defence mechanisms, affecting its response against bacterial plaque attack 25. The components that are most closely related to the risk of periodontitis are dysglycaemia and obesity, but less from atherogenic dyslipidaemia and hypertension, with a risk of increase linked to more MetS components in an individual. However, due to the cross-sectional nature of studies, a direct relationship can’t as yet be established. However evidence suggests that a reduction in serum inflammatory mediators can be achieved through successful periodontal therapy 26. A recent systematic review and meta-analysis reinforces the association between MetS and PD demonstrating a 38% greater likelihood amongst at MetS sufferers to present with PD in relation to those who without 27.

Dental professionals can play a key role in recommending avoiding or reducing the risks to individuals with MetS. Moving from a poor diet of foods with high glycaemic index (GI) towards nutrient rich, high fibre food like fruit and vegetable, as well as maintaining good oral hygiene is fundamental for individuals with MetS. This also has a positive role on affect to improving heart health, reducing tooth loss, which in many alter masticatory function and promotes poor dietary choices 28.

It is important for dental healthcare professionals to understand the oral-systemic links to improving dental health in our patient populations, especially in our present COVID 19 era and oral hygiene recommendations to at-risk groups. I predict we will also soon see an increase in the knowledge base of the significance of the mechanisms of MetS beyond dentistry into the realms of general health. But to understand MetS better we need to take a journey with free thinking fellow healthcare professionals, key influencers,  and protagonists involved in the emergence of this key medical field.

So, to conclude, our current knowledge base from the preceding decades of my first clinical journey into PD to the present has and will continue to evolve. This growing body of research has enhanced the awareness of the links between PD and systemic health in general, but more importantly appropriate specific oral health interventions that can improve health outcomes. I feel the moment will soon come when as allied health professionals we will better combined, collaborative and successful approaches to the treatment of the NCDs.


  1. Tonetti, S. et al (2017). Impact of the global burden of periodontal diseases in health, nutrition and wellbeing of mankind: A call for global action. Journal of Clinical Periodontology.
  2. Jin, L. et al (2016). Global burden of oral diseases: Emerging concepts, management and interplay with systemic health. Oral Diseases.
  3. Chapple, I (2014). Time to take periodontitis seriously. BMJ.
  4. Jepsen, S. et al (2017). Prevention and control of dental caries and periodontal diseases at the individual and populational level: consensus report EFP/ORCA workshop. Journal of Clinical Periodontology.
  5. Poulton, R. et al (2002). Association between children’s experience of socioeconomic disadvantage and adult health: A life-course study. The Lancet.
  6. Watt, R. & Sheilham, A (2012). Integrating the common risk factor approach into a social determinents framework. Community Dent Oral Epidemiology.
  7. Aas, J. et al (2005). Defining the normal bacteria flora of the oral cavity. J. Clin
  8. Amar, S. & Ham, X (2000). The impact of periodontal infection on systemic diseases. Med Sci Monit.
  9. Scamapieco, F (2013). The oral microbiome: Its role in health and in oral and systemic diseases. The Lancet.
  10. Lloyd-Jones, D. et al (1999). Life time risk of developing coronary heart disease. The Lancet.
  11. Blaizot, A. et al (2009). Periodontal diseases and cardiovascular events: Meta-analysis of observational studies: Int Dent J.
  12. World health report (2004). Changing history. World health organization.
  13. Mortality 2016 Data Tables (Provisional) (Ministry of Health, 2018)
  14. Shmerling, R (2018). Gum disease and the connection to heart disease. Harvard Health Publishing.
  15. Batty, D (2018). Oral health and the coronary heart disease: Cohort study of one million people. European Journal of Preventive Cardiology.
  16. Philstrom, B. et al (2005). Periodontal diseases. The Lancet.
  17. Garcia, R. et al (2000). Relationship between periodontal disease and systemic health. Periodontol.
  18. Scamapieco, F (2005). Systemic effects of periodontal diseases. Dent Clin North Am.
  19. Haumschild, M. & Haumschild, R (2009). The importance of oral health in long term care. J. Am Dir Assoc.
  20. Kane, F (2017). The effects of oral health on systemic health. General Dentistry.
  21. Alpert, P (2017). Oral health: the oral-systemic health connection. Home care Manag Pract.
  22. Naito, M. et al (2006). Oral health status and health related quality of life: a systemic review. J.Oral Sci.
  23. Deshpande, N. & Amrutiya, M (2017). Obesity and oral health-is there a link? Pub https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5803880/
  24. Dursun, E. et al (2016). Oxidative stress and periodontal disease in obesity. Pub Med. https://www.ncbi.nlm.nih.gov/pubmed/27015191
  25. Roberts, C. & Sindhu, K (2009). Oxidative stress and metabolic health.https://www.sciencedirect.com/science/article/abs/pii/S0024320509001003
  26. Marchetti, E. et al (2012). Periodontal disease: the influence of metabolic syndrome. BioMed Central.
  27. Lamster, I. et al (2017). Periodontal disease and the metabolic syndrome. https://pubmed.ncbi.nlm.nih.gov/26280008/
  28. Daubt, L, et al (2018) Association between metabolic syndrome and periodontitis: a systematic review and meta-analysis. https://www.ncbi.nlm.nih.gov/pubmed/29846383



Sustaining Host and  Ecological Co-existence within the Habitat of the Mouth. A Whole Dental Health Journey

From David Attenborough to Greta Thunberg, we are actively, perhaps reluctantly, being driven into an age of greater environmental awareness, or to be more honest it appears, a lack of it. There is an increasing urgency in preventing irreparable damage to the ecology of our planet, reducing global warming and protecting innumerable endangered species, we included. This, despite us being willing antagonists and unbeknownst victims, has gathered resonance, even amongst our clients and within our workplaces.

“Use the best available evidence resulting from scientific research, or if absent, strong theoretical rationale, suggestive evidence, or the opinion of respected authorities.”  Section 20. Professional Standards Framework, New Zealand Dental Council

There are now three principals of sustainable practice in my clinical world, what I would term the glocal, the clinical and the oral. The glocal is the local and global environment, what we see in the present burgeoning global pressure groups and political movements championing the cause of protecting the environment. Then we have our workplace and “clinical” settings, the materials and energy we consume and their carbon footprints from the source. The oral model is the recognition that the ecology and habitat in which they dwell require similar ethical consideration, promotion and preservation. Should we continue to advocate a particular method of treatment that locally debrides the microbial habitat within our mouths? Should we learn to be less intense clinically, when in balance, when stable, and more collaborative and aware of their potential dental and health benefits?

We “seek to provide patients with a holistic dental experience that is aimed at providing the best dental preventative care”. Quin Practice Strategic Draft Plan

Picture the scene of a mutually beneficial ecological balance, serving all who positively participate in its management. Imagine this within your mouth, it is seeded at birth, nurtured through the burgeoning early months and years of life where the landscape gradually grows and evolves. New hyper-mineralised structures erupt, in sequence, bringing with them hard surfaces ripe for colonisation. Soft, rough and sleek surfaces shed and slough material regularly, providing residence for microscopic guests with a mixture of gases flowing in and out. Within it are regular temperature changes, the ebb and flow of acidity, alkalinity and resident moisture, lubricating and assisting, in its function. Consider what dwells, lives and thrives within that place and its ecological potential for both dental and general health. Could there be a case for a similar, sustainable and environment movement in our mouths? Isn’t this what a dental healthcare professional should be focused upon when considering a holistic approach to care?

Our oral microbiome (OM) is a natural structure and has a symbiotic relationship with us, the host, delivering essential health benefits in sustaining a mutually shared ecological coexistence. We as humans form a superorganism or “holobiont”, an assemblage of us with many other species living in and around us, forming one ecological unit. Less than half our body, approximately 43%, is human, being made up of 20,000 instructional genes, added to our microbiome of between 2 and 20 million microbial genes. We are home to 500-1000 species of bacteria at any one time, our body’s trillions of microorganisms making up about 1 to 3 per cent of the body’s mass, that’s about 2 to 6 pounds per adult.

“What you see is that the most outstanding feature of life’s history is constant domination by bacteria”. Stephen Jay Gould

Our mouth houses the second most diverse microbial community in the body, harbouring over 700 species of bacteria colonising hard and soft structures of the mouth. The OM is highly regulated, is structurally and functionally organised as a community. The oral habitat constitutes teeth, gingival sulci, a tongue, lips, cheeks, a hard and soft palate and attached gingivae, each offering the right conditions for a variety of distinct bacterial diversity to flourish. However, the modern-day excessive consumption of acidic drinks and refined sugar, or cigarette smoking has deeply impacted upon this ecosystem and beyond.

The health of the oral microbiome has been studied to identify the causes of its dysbiosis, one in which the diversity and relative proportions of species or taxa within the microbiota are disturbed, potentially leading to pathological changes. Research into preserved hunter-gatherer dental calculus has seen the shift from beneficial bacterial composition and declines in microbial diversity witnessed in Neolithic man. This has seen to further increase with the introduction of the modern industrial diet supplying more copious amounts of more highly processed food and drink. The external environment with the widespread and increased use of pesticides, heavy metals, antibiotics and antiseptics contribute significantly too. Consequently, the adaption of species that can develop defences against increased oxidative stress and resistance against acid production has prevailed. This negative change in the numbers and proportions of cariogenic and periodontal pathogenic bacteria has altered the competitiveness and encourages the selection of species best suited to this new environment. The dysbiosis of the OM is also associated with the detriment of general health.

In health, the OM is beneficial to the;

  • Digestive tract, stimulating mucus production.
  • Resisting pathogenic colonisation.
  • Regulation of the cardiovascular system.
  • Host defence mechanism.
  • Production of anti-inflammatory properties.
  • Bodies metabolic potential and antioxidant activity.

A curious example of how the OM support systemic health is in its supplementation of the hosts Nitric Oxide production, unknown until recently by myself. It helps reduce dietary nitrate converting it to nitrite, in turn having the potential to provide critical symbiotic functions in human blood pressure physiology. Adverse changes in the OM can increase blood pressure. The majority of these beneficial bacteria are found on the surface of the tongue, its cleaning appears to favour the increased metabolism and abundance of nitrate to nitrite production. The flow of saliva is also a vital function to improving health affording benefits of;

  • Lubrication, helping in speech.
  • Dilution of sugars from food and drink intake.
  • Antimicrobial action through proteins and peptides including mucins, lactoferrin, lysozyme, lactoperoxidase, statherin, histatins, and secretory immunoglobulin A.
  • Buffering of acids from low to higher pH.
  • Providing a substrate that supports the growth of beneficial bacteria.
  • Remineralisation and repair with the saturation of calcium and phosphate into saliva and teeth.

Also Saliva;

  • Prepares food before digestion, enhancing chewing and swallowing, then clearance.
  • Aids digestion and food breakdown chemically with enzymes.
  • Enhances tasting.
  • Acts as a delivery system for components of innate and adaptive host defences.

Saliva is a solution composed of 99 per cent water, 1 per cent electrolytes and proteins from three salivary glands being controlled by the autonomic nervous system. It has a flow rate of 0.4 – 0.5 ml per minute in healthy subjects. Healthy biofilms are associated with pH values of between 6.5 -7.5, which creates homeostatic and nutritional interdependency amongst bacteria. This, in turn, suppresses and restricts the growth of pathogenic bacteria. When acids are produced, the oral OM compensates by alkaline generation. Critical pH value begins at 5.5 when mineral begins to dissolve, and loss occurs. Above that value saliva and plaque are supersaturated with tooth mineral with repair and remineralisation occurring as a result of bicarbonate buffering.

The stimulation of saliva flow is critical for oral balance in many situations, from dry mouth to lower pH values. The use of non-nutritive sugar alcohol sweeteners like sorbitol, xylitol and erythritol can be consumed in various forms, either in gum or lozenges, added to toothpaste or rinses and used in refined powder form in professional polishing devices clinically. They can also be purchased in granulated forms in health shops. Sorbitol and xylitol treatments have been seen not to affect microbial profiles of saliva and plaque in a 3-week study, with sorbitol increasing the amounts of commensal germs in comparison, effective in particular against Porhyromonas gingivalis, a periodontal pathogen. However, In combination with erythritol, xylitol has been seen to reduce the development of cariogenic bacteria such as S. mutan. Erythritol, a 4 carbon chained sugar alcohol, appears to offer more bacterial support. It is produced from glucose by a fermentation process, and research demonstrates better efficacy than sorbitol or xylitol. It can afford;

Reduced plaque weight and counts of S. mutan in saliva and dental biofilm. Erythritol benefits include;

Effective absorption via the small intestine and is not systemically metabolised, being excreted unchanged within the urine.

  • Zero increases in blood sugars or insulin.
  • Non-caloric benefits and higher gastrointestinal tolerance.
  • Possible improved endothelial function in people with Type 2 Diabetes.
  • Less maturation of oral biofilms and may contribute to healthy oral ecosystems.

Prebiotics are compounds found in food that induces growth or activity of beneficial microorganisms. Some species of commensal streptococci generate energy from arginine, an amino acid.  The metabolism of arginine can lead to ammonia production that can help increase environmental pH.  Ammonia is a compound of hydrogen and nitrogen. Many arginolytic bacteria produce hydrogen peroxide impacting on species associated with periodontal diseases. Probiotics, living microorganisms that deliver health benefits, have yet to have sufficient systematic review evidence to fully support its use dentally. There is little current evidence supporting their reduction of dental caries, but promising research in certain strains of Streptococcus has been found to express arginine deiminase. This helps to inhibit the growth and block critical functions of S. mutans, raising pH and producing bacteriocins that kill S. mutans. Additionally, small benefits are being seen in the management of gingivitis and periodontitis.

“Am I simply a vehicle for numerous bacteria that inhabit my microbiome? Or are they hosting me”? Timothy Morton

“Simply eradicating all OM sub and supra gingivally, without exception, in pursuit of biological balance allows the onus on dental health promotion as being primarily focused instrumentally”.  Mark James RDH NZ

This bellies the benefits of environmental, ecological and sustainable approaches to dental disease prevention. We must consider working in harmony with nature rather than obliterating it where it presents as healthy. Each and every oral health assessment needs to be mindful of the benefits of a balanced OM, not blinded by visual plaque levels but the degree to which it appears dysbiotic. Bleeding on probing on intra-oral examination and observing historical risk needs a blended approach with dietary and other lifestyle behaviour advice and management. This will require greater use of clinical time in communicating this environmental and sustainable dental message. Being more holistic in its nature, it can also embrace the broader general health benefits of the symbiotic relationships between host, saliva and OM.

The “Mouth is the gateway to the total body wellness; thus, oral microbiome influences the overall health of an individual”. Sharma et al

I can envisage little resistance from many of my clients who have environmental values like myself. My workplace markets itself as being natural, but I do anticipate discourse with colleagues as to the application of my interpretation of holistic and sustainable practice.


More than half your body is not human. https://www.bbc.com/news/health-43674270

In Sickness and in Health-What Does the Oral Microbiome Mean to Us? An Ecological Perspective. Marsh, 2018. https://www.ncbi.nlm.nih.gov pubmed/29355410 /

Can xylitol used in products like sweets, candy, chewing gum and toothpaste help prevent tooth decay in children and adults? Riley et al., 2015. https://www.cochrane.org/CD010743/ORAL_can-xylitol-used-in-products-like-sweets-candy-chewing-gum-and-toothpaste-help-prevent-tooth-decay-in-children-and-adults

Effect of erythritol on the microbial ecology of in vitro gingivitis biofilms. Janus et al., 2017.


Exploration of singular and synergistic effect of xylitol and erythritol on causative agents of dental caries. Koljalg et al., 2020. https://www.nature.com/articles/s41598-020-63153-x?proof=trueMay%252F

Erythritol Functional Roles in Oral-Systemic Health. De Cock, 2018. https://journals.sagepub.com/doi/full/10.1177/0022034517736499#

The role of natural salivary defences in maintaining a healthy oral microbiota. Pederson & Belstrom, 2019. https://www.sciencedirect.com/science/article/pii/S030057121830335X

Oral microbiome and health. Sharma et al., 2018. https://www.ncbi.nlm.nih.gov/pubmed/31294203

Erythritol Is More Effective Than Xylitol and Sorbitol in Managing Oral Health Endpoints. De Cock et al., 2016. https://www.hindawi.com/journals/ijd/2016/9868421/

The Effect of Xylitol on the Composition of the Oral Flora: A Pilot Study. Soderling et al., 2011. https://www.thieme-connect.com/products/ejournals/pdf/10.1055/s-0039-1698855.pdf

The effect of xylitol on dental caries and oral flora. Nayak et al., 2014. https://www.ncbi.nlm.nih.gov/pubmed/25422590

Xylitol and sorbitol effects on the microbiome of saliva and plaque. Rafeek et al., 2019. https://www.tandfonline.com/doi/full/10.1080/20002297.2018.1536181

https://www.nature.com/articles/bdjteam2015123 Saliva A review of its role in maintaining oral health and preventing dental disease. Dodds 2015. https://www.nature.com/articles/bdjteam2015123

Oral microbiomes: more and more importance in oral cavity and whole body. Gao et al., 2018. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5960472/

Human Oral Microbial Ecology and Dental Caries and Periodontal Diseases. Liljemark & Bloomquist, 1996. https://journals.sagepub.com/doi/abs/10.1177/10454411960070020601

The oral microbiome – an update for oral healthcare professionals. Kilian et al., 2016. https://journals.sagepub.com/doi/abs/10.1177/10454411960070020601

Oral Dysbiotic Communities and Their Implications in Systemic Diseases. Sudhakara et al., 2018. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6023521/

The oral microbiome: A Lesson in coexistence. Sultan et al., 2018. https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1006719

Frequency of Tongue Cleaning Impacts the Human Tongue Microbiome Composition and Enterosalivary Circulation of Nitrate. Tribble et al., 2019. https://www.frontiersin.org/articles/10.3389/fcimb.2019.00039/full

The role of natural salivary defences in maintaining a healthy oral microbiota. Pedersen & Belstrom, 2018. https://www.sciencedirect.com/science/article/pii/S030057121830335X


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