Oral Polymicrobial Communities in Health and Disease

Abstract

The oral microbial community represents the best-characterized consortium associated with the human host. There are strong correlations between the qualitative composition of the oral microbiota and clinically healthy or diseased states. However, additional studies are needed to elucidate the mechanisms that define these microbial/host relationships. In the following chapters, the relationship between host and polymicrobial communities in the oral cavity will be explored in the context of health and disease. The oral and intestinal host tissues both carry a heavy microbial burden. It is well established that the commensal bacteria contribute to healthy intestinal tissue structure and function however; their contribution to oral health is poorly understood. A crucial component of periodontal health is the recruitment of neutrophils to periodontal tissue. Within the subsequent pages, examination of polymicrobial effects on the process of neutrophil homing will reveal a unique role for commensal bacteria in oral health. Further, it appears that the commensal-host relationship in health is a delicate balance between boosting host-immune functions and commensal induced bone loss. As we will see during an in vivo investigation of Porphyromonas gingivalis heterogeneous lipid A that immunomodulation caused by different agents can cause disruption and dysbiosis to the commensal community. The unique dysbiotic communities were each associated with a similar progression of disease. The data presented in the following pages will hopefully give insight into the complex nature of oral commensal microbiota in health as well as disease and provide a foundation for future studies.