Spatial Variation in the Healthy Human Lung Microbiome and the Adapted Island Model of Lung Biogeography

In healthy lungs, spatial variation in microbiota within an individual is significantly less than variation across individuals. The lung microbiome in health is more influenced by microbial immigration and elimination (the adapted island model) than by the effects of local growth conditions on bacterial reproduction rates, which are more determinant in advanced lung diseases. BAL of a single lung segment is an acceptable method of sampling the healthy lung microbiome. Clinical trial registered with www.clinicaltrials.gov (NCT02392182).