Comparing the healthy nose and nasopharynx microbiota reveals continuity as well as niche-specificity.

To improve our understanding of upper respiratory tract (URT) diseases and the underlying microbial pathogenesis, a better characterisation of the healthy URT microbiota is crucial. In this large-scale study, we obtained more insight in the URT microbiota of healthy adults. Hereto, we collected paired nasal and nasopharyngeal swabs from 100 healthy participants in a citizen-science project. High throughput 16S rDNA gene V4 amplicon sequencing was performed and samples were processed using the DADA2 algorithm. This allowed us to identify the bacterial richness and diversity of the samples in terms of amplicon sequence variants (ASVs), with special attention to intragenus variation.