In 2010, the first study regarding the lung microbiome in asthma and healthy controls was publishe; before this date the lower airways were considered sterile.10, 11, 12 The upper respiratory airways in childhood asthma are colonized by Haemophilus influenza, Moraxella catharralis,and Streptococcusspp that are associated with increased ex vivo Th2 cytokines such as IL-5, IL-13, and IL-17.13 This evidence concerns the gene IL17A and asthma.