Airway Microbiome in Different Inflammatory Phenotypes of Asthma: A Cross-Sectional Study in Northeast China

Background and Objective: Asthma is a common respiratory disease with a high prevalence and morbidity that can seriously affect quality of life. Microbial colonization of the airway may participate in the pathogenesis of asthma, however the mechanisms involved have not been established. In the present study, we aimed to determine the composition of the microbiota in different asthmatic phenotypes from Northeast China. Methods: 24 mild-to-moderate asthmatics (10 eosinophilic asthma and 14 non-eosinophilic asthma) and 12 healthy volunteers participated in this cross-sectional study. DNA was extracted from their induced sputum and amplified for 16s rRNA gene sequencing on Illumina Miseq platform. Bioinformatic analysis on the microbiome was performed. Results: Alpha-diversity analysis showed that the asthmatics had a decreased richness, evenness and diversity. Non-eosinophilic asthmatics showed a decreased richness, evenness and diversity compared with eosinophilic patients. A different taxonomy of 1 phylum and 6 genera taxa between the phenotypes was identified. Compared with heathy controls, asthmatics existed a larger taxonomic difference (P<0.05 for both EA and NEA vs. HC). 5 genera as the dominance in the microbial co-occurrence network correlated with the spirometry and disease progression of asthma. The function of microbiota genes was predicted to be related with infectious, immune and metabolic diseases. Conclusion: The diversity and composition of the airway microbiome was associated with the pathogenesis of asthma in different phenotypes. The diverse composition has been identified in the present study.