Comparison of nasal microbiota between term and preterm infants at mean post-menstrual age of 45 weeks

Abstract

<b>Background:</b> Respiratory microbiota composition is important for the maturation of the immune system in infancy. Despite significant past work, little is known about the composition of nasal microbiota of premature infants and the difference compared to nasal microbiota of healthy, term infants. <b>Aims</b> To compare nasal microbiota of preterm and term infants at mean post-menstrual age of 45 weeks and to evaluate the impact of environmental factors (e.g. oxygen supply, mechanical ventilation, antibiotic and probiotic therapy, age, etc.) on the nasal microbiota in preterm infants. <b>Methods:</b> Samples were collected within the prospective Basel-Bern Infant Lung Development (BILD) birth cohort. Nasal swabs, obtained from 299 term and 136 preterm infants, were analyzed by 16S rRNA gene amplification (V3-V4 region) and sequencing (Illumina MiSeq). <b>Results:</b> The taxonomic α-diversity measured by the Shannon index indicated that the diversity of nasal microbiota was lower in preterm infants who had postnatal antibiotic use than those without antibiotic treatment. No significant α-diversity differences were found between term and preterm infants. However, β-diversity measured by principal coordinate analysis showed that the microbiome compositions were diverse between term and preterm infants (PERMANOVA p-value=0.001). The abundance of Staphylococcus was significantly higher, while Moraxella and Dolosigranulum were lower in preterm than in term infants. <b>Conclusion:</b> Our findings suggest that nasal microbiota composition is associated with preterm birth. This may be a relevant modifier of immune system development in this risk group, that is prone to recurrent subsequent wheezing disorders in infancy.