Following on from last month’s blog about how many dentists the world needs to address the challenges of population oral health, I have been giving some thought to the other complexities of oral healthcare. There are a variety of innovative ideas that are emerging to help both populations and our profession reduce the burden of care. Problems and solutions go hand-in-hand, and necessity is invariably the mother of invention.
We all work hard for our patients and during a spare moment on clinic yesterday, my thoughts turned to thinking about how the dental team could reduce overall microbiological loading as a method of population oral health improvement. This is a topic that has captured the imagination over the years with interest re-surging in dentistry with the advent of personalised oral health planning rather than blanket population healthcare provision. All dental health professionals are aware of the inevitability for antibiotics as part of the solution for severe dental infections issues and the issues of antibiotic resistance and if we could manipulate the host-parasite relationship, we have another potential solution for improving oral health.
Our bodies are estimated to carry around 100 trillion microorganisms, around half of our body weight with the majority of these are in the oro-digestive tract. Of these, 20 billion (that is 10 zeros….) live in our mouths, with around 700 different species of bacteria alone, not forgetting the fungi, viruses, protozoa and so on. Streptococcus Mitis, Prevotella, Actinomyces, Neisseria, and the Rothia species make up 75% of the total. My first publication was a video on how to ‘don’ and ‘doff’ gloves (handschoenen, which literally translates as hand shoes) during an elective in the Netherlands as a student. With the yucky oral environment, I am glad to have worn gloves ever since.
Probiotics have been marketed for decades in relation to overall gut health but what about oral health you say? Probiotics are a novel concept in dentistry, and it would be fantastic if oral microbial loading and the constituents of dental plaque could be adjusted. Prebiotics, synbiotics and postbiotics are also being increasingly explored for changing oral health through modulation of the oral microbiome. Could these be a game-changer? If so, this would be major step forwards and could help in the fight against antimicrobial resistance by reducing the number of dental events requiring antibiotics.
Probiotics are bacteria and yeasts (Lactobacillus, Bifidobacterium, Saccharomyces boulardii) that maintain the balance of microflora in the gut, and it is thought that they boost immune function and overall health. Probiotics have been marketed for some time as “healthy bacteria” (not forgetting the yeasts) and by promoting healthy microorganisms in the mouth, could these reduce oral disease? The good news is that evidence is emerging that using lactobacillus and bifidobacterium, the proliferation of Streptococci on tooth surfaces can be inhibited and as a result, dental caries can be reduced. Probiotics inhibit periodontal pathogens and the biochemical inflammatory markers including interleukin (IL)-beta, matrix metalloproteinase (MMP)-8 and tissue inhibitor of metalloproteinase (TIMP)-1. Whilst probiotics has been demonstrated to be effective in some studies with chewing gum, tablets, toothpaste, mouthwash and lozenges, time will tell if these can be used in periodontal therapy as well as maintenance.
Prebiotics on the other hand are non-digestible components of food, generally fibre that encourage growth of beneficial gut bacteria. Inulin is found in bananas, onions and garlic and is known to be effective in the growth of beneficial gut bacteria. Fructooligosaccharides are also present in a number of vegetables and fruit and are known to stimulate probiotic gut growth. Prebiotics have been tested in dentistry. In relation to dental caries, substantial reductions in cariogenic microflora have been demonstrated and have the potential to be simple and safe yet economically viable in the reduction of dental case, particularly among children where disease is unequally spread.
Synbiotics are combined prebiotics and probiotics providing both the microorganisms and the required nutrients in order to produce a balanced gut microbiome. Synbiotics offer the theoretical best of both worlds and the combination of prebiotic with a probiotic has a degree of logic bearing in mind the information above. Evidence is emerging that combining arginine with an appropriate bacteria reduces the biomass of streptococcus mutans and also reduces the lactate content, resulting in no pH decline and therefore modulating the ecology of the dental plaque. However, it is early days for synbiotics, considerable research is still needed.
Postbiotics and the output from probiotic metabolism includes substances such as short-chain fatty acids produced during the fermentation of fibre, known to reduce inflammation, boost the gut barrier function and improve overall immunity. Postbiotics are an interesting area of research and have the potential to be superior to probiotics due to their stability, ease of storage and safety. In addition, postbiotics are unlike probiotics as they are not sensitive to either oxygen or heat. This allows postbiotics to be added to common products such as toothpaste, chewing gum and foodstuffs.
It remains that a lot of work needs to be done on probiotics, prebiotics, synbiotics and postbiotics before these become widely used in oral healthcare. Initial outcomes are promising, particularly in changing the balance of the oral microbiome through the introduction of beneficial microorganisms and other substances. Whilst lifestyle factors such as halitosis can already be successfully treated through probiotics, it would be interesting to see how these along with prebiotics, synbiotics and postbiotics can be developed, specifically for personalised prevention and treatment of not only dental caries but periodontal disease.
This area of research intrigues me and I hope that researchers will continue to explore this area for time to come while in the meantime the profession also concentrates on generating a sizeable additional dental workforce in order to help address population overall health in conjunction with the worthwhile lifestyle messages around controlling caries and periodontal disease. It is an exciting area and another opportunity to avoid the need for antimicrobials in the first place for dental infections. Moreover, by changing the oral microbiome, we would be able to make a significant positive impact on systemic health as well, a definite win-win.
If you would like to get in touch with me, please email me dental@rcsed.ac.uk.