Airway microbiota correlated with pulmonary exacerbation in primary ciliary dyskinesia patients

Objective: Primary ciliary dyskinesia (PCD) is characterized by symptoms such as productive cough, rhinitis, and recurrent infections in both the upper and lower airways, which can lead to chronic infection, bronchiectasis, and decreased pulmonary function. Our study aimed to analyze the diversity and composition of the microbiota in the respiratory tract and investigate the correlation of the microbiota with pulmonary exacerbation in PCD patients.Methods: This study employed 16S rRNA amplicon sequencing to explore the microbiota present in both BALF and sputum samples collected from PCD patients.Results: Eighty-five airway samples (17 BALF and 68 sputum samples) were collected from 72 patients aged 2 months to 60 years. Significantly lower sputum microbiota diversity and richness were found in the pulmonary exacerbation group than in the pulmonary stabilization group; additionally, the relative abundance of Pseudomonas increased when pulmonary exacerbation occurred. There was a positive correlation between pulmonary exacerbation and the relative abundance of Pseudomonas, while Streptococcus, Moraxella and Haemophilus showed a negative correlation. Although there was no significant difference in the sputum microbiota diversity and composition in children aged 6-18 years with pulmonary exacerbation, Pseudomonas increased during pulmonary exacerbation. BALF samples of pediatric patients with pulmonary exacerbation had a lower microbiota diversity and richness; furthermore, Pseudomonas had a higher abundance and a moderate distinguishing effect.Conclusion: We found that microbiota beta diversity and dominance were decreased during pulmonary exacerbation. Additionally, Pseudomonas had a higher abundance and moderate distinguishing effect in pediatric patients with pulmonary exacerbation.