Airway Microbiome Profiling in Adult Survivors of Extremely Preterm Birth (The EPICure Study)

Rationale: Bronchopulmonary Dysplasia (BPD) is a major complication of preterm birth that leads to lifelong respiratory morbidity. The EPICure Study has investigated the longitudinal health outcomes of babies born extremely preterm (<26 weeks gestation).Objectives: To characterise the airway microbiome in young adults born extremely preterm (EP), with and without neonatal BPD, in comparison to matched full term-born controls.Methods: Induced sputum was collected from 51 young adults born extremely preterm (37 with BPD, 14 without) and 41 controls, all at age of 19 years. 16S-rRNA gene (v5-v7) was amplified from 74 samples and sequenced on Illumina Miseq-platform. Typical respiratory pathogens were detected using quantitative-PCR.Results: The extremely preterm group with neonatal BPD had the least diverse bacterial communities. The airway microbiome profile was dominated by Firmicutes followed by Bacteriodetes and Proteobacteria in the three groups. The Bacteriodetes relative-abundance, particularly Prevotella melaninogenica was significantly lower in the extremely preterm groups compared to controls. This decline was balanced by a nonsignificant increase in Firmicutes. Total Prevotella relative-abundance correlated with FEV1 z-score (?=0.272; P<0.05). Typical respiratory pathogens' loads and prevalence were similar between groups. Streptococcus pneumoniae and Haemophilus influenzae were highly prevalent, each with a mean load 4.44 log10CFU/mL. Conclusion: The airway microbiome profiles in young adults born extremely preterm were similar regardless of the BPD history. It is characterised by a shift in the community composition away from Bacteriodetes as manifested in a significant drop in Prevotella relative-abundance compared to controls. Extremely preterm birth is associated with a significant dysbiosis in airway microbiome in young adulthood.