Dynamic Upper and Lower Airway Microbiotas in Paediatric Bronchiectasis Exacerbations: A Pilot Study

Area of Science:

• Microbiology
• Pediatric Pulmonology
• Respiratory Medicine

Background:

• Non-cystic fibrosis bronchiectasis is a childhood respiratory condition with diverse causes, some reversible with early intervention.
• Respiratory exacerbations significantly impact bronchiectasis progression.
• Understanding airway microbiota dynamics during exacerbations and treatment is crucial for managing the disease.

Purpose of the Study:

• To investigate the upper and lower airway microbiota composition in children with bronchiectasis during exacerbations and antibiotic treatment.
• To identify changes in microbial diversity and abundance in response to treatment.

Main Methods:

• Pilot study involving children aged 1-15 undergoing antibiotic treatment for bronchiectasis exacerbations.
• Collection of sputum and nasal swabs before and after antibiotic therapy.
• DNA extraction, 16S rRNA gene amplification, and Illumina MiSeq sequencing for microbiota analysis.

Main Results:

• Significant alterations in airway microbiota composition were observed during exacerbations and treatment.
• A notable reduction in the relative abundance of *Haemophilus* was detected post-antibiotic treatment.
• No significant changes in alpha-diversity were found over the course of treatment.

Conclusions:

• A reduction in *Haemophilus*, a bacterium linked to severe respiratory symptoms, may indicate a positive shift in the airway microbiome.
• Current antibiotic treatments for bronchiectasis appear to modulate microbiota composition while potentially preserving overall bacterial diversity.