How is the development of dental biofilms influenced by the host?

BACKGROUND: The host provides environmental conditions that support diverse communities of microorganisms on all environmentally-exposed surfaces of the body. MATERIALS AND METHODS: To review the literature to determine which properties of the host substantially influence the development of dental biofilms. RESULTS: The mouth facilitates the growth of a characteristic resident microbiota. The composition of the oral microbiota is influenced by temperature, pH, and atmosphere, as well as by the host defences and host genetics. In addition, the host supplies endogenous nutrients and a variety of surfaces for biofilm formation. In health, the resident oral microbiota forms a symbiotic relationship with the host, regulated by active host-microbe cross talk. This resident microbiota is sensitive to perturbations in the host environment, especially to changes in nutrient supply and pH, so that previously minor components of the microbiota can become more competitive (and vice versa), resulting in reorganization of biofilm community structure. CONCLUSION: The host environment dictates the composition and gene expression of the resident microbiota. Changes in oral environmental conditions can disrupt the normal symbiotic relationship between the host and its resident microbes, and increase the risk of disease.