Polymicrobial nature of chronic oral disease

Abstract

Recent microbiome studies have shown that the human oral microbiome is composed of over 260 abundant bacterial species that predominantly live as polymicrobial biofilms accreted to the non-shedding hard surfaces of the teeth. In addition representatives of both Archaea and Fungi are found in the oral cavity and there is considerable colonisation of the soft tissues of the mouth. Most of these species are commensal and form complex biofilm communities that restrict the colonisation of the oral cavity by exogenous bacteria. Changes in the polymicrobial biofilm microenvironment such as those resulting from the effects of chronic inflammation for subgingival plaque, can lead to the emergence of opportunistic pathogens resulting in dysbiosis and the development of chronic diseases such as periodontitis in a susceptible host. The application of microbiomic studies to the analysis of these complex and dynamic communities in rigorously designed human clinical studies will provide valuable mechanistic insight into the bacterial succession and complex interactions involved in the development of dysbiosis and disease.