Airway Microbiome of Preterm Infants Bronchopulmonary dysplasia is the chronic lung disease of prematurity with an operational definition, various different clinical phenotypes, and a complex, multifactorial etiology. Newer unbiased systems biology approaches have identified various “omic” factors associated with the pathogenesis and prediction of BPD. Recent microbi “omic” studies have discovered that airways of new-borns harbor a low biomass but distinct microbiome signature as early as at the time of birth. This early airway microbiome may serve to prime the host immune system and may play a role in modulating the infant's future susceptibility to severe BPD development. Temporal changes are observed in airway microbiome of preterm infants from birth to the diagnosis of BPD, with an overall decrease in bacterial diversity, and development of a relative dysbiosis marked by increased Gammaproteobacteria and decreased Lactobacilli abundance. Distinct microbial populations exist throughout the human body and have been the subject of investigation relating to human disease pathogenesis, susceptibility, and progression. The airway microbiome has been studied in the context of multiple pulmonary diseases including chronic obstructive pulmonary disease, asthma, and cystic fibrosis. Bronchopulmonary dysplasia (BPD), the most common chronic lung disease of prematurity, may result from lung injury due to a range of factors including infection, respiratory support, edema, and oxygen toxicity. Regards John Editorial Assistant Clinical Pediatrics