The commensal flora-immune system interactions that help to maintain oral health is an understudied area. The flexibility of the immune system related to the immunobiography and aging effects on this response repertoire clearly has a critical component of interactions with the commensal or autochthonous microbiome of an individual. We still know little regarding how commensal bacteria help program symbiotic immune responses, nor how changes in the commensals or emergence of pathogens can undermine the profile of symbiotic response interactions leading to an immune system that contributes to pathophysiological processes and clinical features of periodontitis. Specific research questions include:
1) Are there members of the commensal flora that produce anti-inflammatory agents or other beneficial immunomodulatory functions?
2) Does the commensal flora play a role in educating the oral immune response?
3) Can the commensal flora reverse a pathogenic immune response during disease?
4) What is/are the keystone species promoting oral immune homeostasis?