Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2017-06-15, 09:30:22 | version 1.38.0
16 TRENDS & APPLICATIONS Dental Tribune United Kingdom Edition | 4/2017 “The natural oral microbiome is not associated with oral disease” An interview with University of Leeds Professor Philip Marsh By DTI As Professor of Oral Microbiology at the University of Leeds, Philip Marsh has received national and in- ternational awards for his research AD in the field and is a regular confer- ence speaker. At the Australian Dental Congress, where he recently presented three lectures on the topics of dental biofilms and oral microbial ecology , Dental Tribune Asia Pacific had the opportunity to speak with him about the relation- ship between lifestyle factors and the microbial composition and how to best maintain a healthy bacterial balance in the mouth. Dental Tribune Asia Pacific: The mi- crobial balance of the oral cavity is essential for dental (and overall) health. Could you briefly explain this relationship? Prof. Philip Marsh: Humans and microorganisms have evolved to have a close and important symbiotic relationship, to the ex- tent that we are 50 per cent micro- bial! These microorganisms [the human microbiome] are natural and deliver essential health bene- fits. In the mouth, the normal oral microbiome prevents colonisa- tion by external microbes—some of which would be potentially pathogenic—and contributes to the development of our host de- fences and cardiovascular system. The natural oral microbiome is closely linked to oral health and is not associated with oral disease. The oral microbiota is vulnerable to disruption by lifestyle and environ- mental changes. What exactly can register for FREE – education everywhere and anytime – live and interactive webinars – more than 1,000 archived courses – a focused discussion forum – free membership – no travel costs – no time away from the practice – interaction with colleagues and experts across the globe – a growing database of scientific articles and case reports – ADA CERP-recognized credit administration www. DTStudyClub.com Join the largest educational network in dentistry! ADA CERP is a service of the American Dental Association to assist dental professionals in identifying quality providersof continuing dental education. ADA CERP does not approve or endorse individual courses or instructors, nor does it imply acceptance of credit hours by boards of dentistry. cause a shift and what are poten- tial consequences? The symbiotic relationship be- tween the oral microbiota and the host is dynamic and can alter if the oral environment undergoes a substantial change, often as a con- sequence of an altered lifestyle. A clear example is when salivary flow is reduced or when an indi- vidual more regularly consumes sugar-containing foods and bev- erages. In this situation, the dental biofilm spends more time at an acidic pH. This leads to an enrichment of acid-producing and -tolerating bacteria at the expense of benefi- cial organisms and increases the risk of dental caries. Similarly, the host mounts an inflammatory response if biofilm accumulates around the gingival margin. If this fails to reduce the microbial load, then the protein-rich gingival exu- date that delivers the host defences inadvertently acts as a novel sup- ply of nutrients for the proteolytic and obligately anaerobic bacteria in subgingival biofilms. These bac- teria subvert the host response and continue to drive inflammation; this exaggerated response is re- sponsible for host tissue damage. Is the composition of the oral microbiota mainly based on hered- ity or can it be managed through external factors? Some elements of the make- up of the oral microbiota are linked to heredity, but the gen- eral composition and activity of these microbes can be managed by effective oral hygiene and an appropriate lifestyle, for exam- ple reducing the amount and fre- quency of intake of fermentable sugars in the diet, avoidance of tobacco-smoking, etc. An unin- tended side-effect of some medi- cations can be a reduction of sal- ivary flow; this would disturb the natural balance of the oral microbiota and increase the risk of dental caries. Dental care products aim to reduce harmful bacteria while maintaining the good ones. Is there a danger of using too much product and thereby destroying the oral flora? The oral microbiota is natu- ral and beneficial and therefore needs to be managed and main- tained at levels compatible with oral health. Oral care products are designed and evaluated to support the patient in maintain- ing an appropriate level of oral micro-organisms, so if they are used as intended, there is little danger of negatively disrupting the oral microbiota. In contrast, the long-term use of broad-spec- trum antibiotics can lead to the suppression of significant num- bers and types of beneficial oral bacteria, and this can result in overgrowth by yeasts or environ- mental microbes. Bacteria play an important role in the development of diseases such as periodontitis or caries. Are there ways to manage harmful coloni- sation other than with dental hygiene measures, for example with vaccines, or will there be in the future? New strategies to promote beneficial oral bacteria and/or to suppress the likelihood of disease are being developed. These strate- gies include the development of oral probiotic bacteria to prevent dental disease and the use of preb- iotics, which are supplements de- signed to boost the growth of ben- eficial bacteria. Novel anti-inflam- matory agents are being evalu- ated that would promote wound healing and reduce the tissue damage caused by a subverted host response to subgingival den- tal biofilms. Molecules that re- duce biofilm formation or inhibit species implicated in dental dis- ease are under active investiga- tion. Some snack foods and drinks contain sweeteners that cannot be metabolised into acid by oral bacteria. Is dentistry experiencing greater challenges with regard to biofilms and bacterial shifts today than in the past, and if so, why? The main differences today compared with the past probably surround the increased amounts of sugar in snack foods and drinks. Also, people are living longer and are retaining their teeth into later life, so the dentition is vulnerable to dental disease for longer, and this is coupled with the fact that a side-effect of many medications taken by the elderly is a reduction in salivary flow. What strategies for keeping a healthy balance in the mouth can dentists teach patients? The main strategies are for pa- tients to practise effective oral hy- giene and thereby reduce biofilm accumulation and to appreciate the impact of sugar in their diet on their risk of dental caries. It may be helpful if patients realise the relationship and direct link be- tween their lifestyle, their oral microbiome, and their oral and general health and well-being. Thank you very much for the inter- view.