Haemophilus dominance and effect of antibiotic therapy on the airway microbiome in COPD

ABSTRACT Background Long term antibiotics have a poorly defined role in the management of chronic obstructive pulmonary disease (COPD) and there is limited information regarding their effect on the airway microbiome. We prospectively analyzed baseline communities and changes with antibiotic treatment of the airway microbiome in COPD. Methods Seventy-one patients with stable COPD received 13 weeks’ treatment with azithromycin, doxycycline, moxifloxacin or placebo as part of a randomized controlled trial. Sputum was analyzed before and after treatment for total bacterial load by 16S rRNA qPCR and inflammatory markers by ELISA. The airway microbiome was characterized by sequencing the V3–V4 region of the 16S rRNA gene. Conclusions We show a distinct phenotype of patients with stable COPD in whom the microbiome is dominated by Haemophilus influenzae. These patients demonstrate greater airway inflammation and bacterial burden and importantly have an improved inflammatory response to long term antibiotic therapy.