Saliva as a Window into the Human Oral Microbiome and Metabolome

Abstract

The human oral cavity is colonized by one of the densest bacterial communities on the planet, with consistent microbial composition throughout life and in response to perturbations such as tooth cleaning. The oral microbiome has important associations with health in the context of gingivitis and even heart disease and preterm birth. In this chapter, we will provide an overview of what is known about the human oral microbiome, starting from the first glimpse of microbes when van Leeuwenhoek looked at his own oral microbes with the first microscope, to recent expansion of knowledge with both high-throughput sequencing and microscopy. We will describe what is known about healthy oral microbial communities, including how they develop in childhood and become shared within families and others who cohabitate, and how the biogeographic and biophysical forces drive construction of largely anaerobic microbial communities unique to each tooth. Finally, we touch on what is known about health-and disease-associated human oral microbial communities and briefly discuss the potential for using saliva samples to monitor health.