Role of the Oral Microflora in Health

Microbial Ecology in Health and Disease 07/2009; 12(3):130-137. DOI: 10.1080/089106000750051800


The mouth contains both distinct mucosal (lips, cheek, tongue, palate) and, uniquely, non-shedding surfaces (teeth) for microbial colonisation. Each surface harbours a diverse but characteristic microflora, the composition and metabolism of which is dictated by the biological properties of each site. The resident oral microflora develops in an orderly manner via waves of microbial succession (both autogenic and allogenic). Pioneer species (many of which are sIgA protease-producing streptococci) colonise saliva-coated surfaces through specific stereo-chemical, adhesin-receptor interactions. The metabolism of these organisms modifies local environmental conditions, facilitating subsequent attachment and growth by later, and more fastidious, colonisers. Eventually, a stable biofilm community develops, that plays an active role in (a) the normal development of the physiology of the habitat, and (b) the innate host defences (colonisation resistance). Thus, when considering treatment options, clinicians should be aware of the need to maintain the beneficial properties of the resident oral microflora.

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Available from: Philip D Marsh
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    • "The tongue community in healthy subjects has previously been found to comprise mostly Streptococcus spp., Veillonella spp., and Actinomyces spp. [31, 32]. A recent study looking into the unculturable microbiota of the tongue has also identified the above genera, along with a Lysobacter-type species as the predominant organism found on the tongue [33]. "
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    ABSTRACT: Gingivitis is a preventable disease characterised by inflammation of the gums due to the buildup of a microbial biofilm at the gingival margin. It is implicated as a precursor to periodontitis, a much more serious problem which includes associated bone loss. Unfortunately, due to poor oral hygiene among the general population, gingivitis is prevalent and results in high treatment costs. Consequently, the option of treating gingivitis using functional foods, which promote oral health, is an attractive one. Medicinal mushrooms, including shiitake, have long been known for their immune system boosting as well as antimicrobial effects; however, they have not been employed in the treatment of oral disease. In the current study, the effectiveness of shiitake mushroom extract was compared to that of the active component in the leading gingivitis mouthwash, containing chlorhexidine, in an artificial mouth model (constant depth film fermenter). The total bacterial numbers as well as numbers of eight key taxa in the oral community were investigated over time using multiplex qPCR. The results indicated that shiitake mushroom extract lowered the numbers of some pathogenic taxa without affecting the taxa associated with health, unlike chlorhexidine which has a limited effect on all taxa.
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    • "Some bacteria are harmless in the natural environment , but could become a threat in an immunocompromised animal (Higgins, 2000). Normal bacterial flora are necessary for a healthy existence and contribute by occupying a niche and controlling overgrowth of potentially pathogenic species that could result in infection and disease (Marsh, 2000; Iwase et al., 2010). For instance, Iwase et al. (2010) found that Staphylococcus epidermidis, a common nasal colonizer, can inhibit the growth and proliferation of S. aureus, a potential pathogen, in humans. "
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    • "While the majority of them are normal/commensal bacteria, some of them are opportunistic pathogens responsible for the development of oral microbial infectious diseases such as dental caries and periodontitis [3]. Saliva as an oral circulating fluid is heavily laden with bacteria (108 – 109 cfu/mL) [4]. These salivary bacteria reflect the oral microbiota composition and could serve as an indicator of the health and disease status of oral cavity. "
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