Introducing the microbiome, lessons from the healthy lung and CF

The microbiome of the upper respiratory tract (URT), including the nasopharyngeal and oropharyngeal microbiota, is a dynamic community of microorganisms as diverse as the gastrointestinal microbiome. Until recently, the lower airways of healthy individuals were considered to be effectively sterile. This has been challenged by recent studies, and the best evidence suggest the lungs of healthy individuals are transiently colonized by microbes of the URT. In cystic fibrosis the chronic colonization of the lower airways by bacterial pathogens is the leading cause of morbidity and mortality. It is now well establishe…