Airway microbiota is associated with the severity of non-CF bronchiectasis.

BACKGROUND: Airway microbiota are associated with several chronic respiratory diseases. However, limited studies examined microbiota in non-cystic fibrosis (non-CF) bronchiectasis, especially its relationship with severity and immunology. OBJECTIVES: We characterized the microbiota of patients with different severities of bronchiectasis and examined the correlation between microbiota and the immunological indices. MATERIALS AND METHODS: The microbiota of 63 sputum samples from 40 patients with bronchiectasis were analyzed by 16S rRNA gene sequencing. Blood tests and related immunological indices were detected. RESULTS: According to the baseline data of patients with bronchiectasis, we found that more severe bronchiectasis was accompanied by lower prealbumin levels. The 16S rRNA sequencing analyses demonstrated that Pseudomonas-dominated microbiota produced lower levels of interleukin-4 (IL-4) and transforming growth factor-ß (TGF-ß) compared to other-dominated microbiota. The airway microbiota of patients with mild bronchiectasis clustered apart from those of patients with severe bronchiectasis, which correlated with IL-4 and other clinical indices. CONCLUSION: There are differences in the airway microbiota between patients with mild and severe bronchiectasis. The airway microbiota was related to some clinical indices that represent effects on the immune system.