Research progress on bronchiectasis and lower respiratory tract flora

With culture-independent DNA-based molecular techniques, the dogma “lung is sterile” has been overturned thoroughly. The lower respiratory tract has flora with lower biomass which is homologous to the upper respiratory tract. Bacteria colonization plays an important role in the “vicious cycle” of non-cystic fibrosis bronchiectasis, and pseudomonas aeruginosa is associated with the exacerbation of bronchiectasis. Oral and inhalant antibiotics are commonly used clinically, but macrolide maintenance therapy could significantly lead to the increase of macrolide-tolerant organisms. So we try to summarize the profile of lower respiratory tract flora, and the relationship between the bronchiectasis stable and exacerbated periods and the lower respiratory tract flora, hoping to provide enlightenment for the prevention and treatment of the bronchiectasis.