Microbiome profiling reveals distinct microbial compositions of nasal polyps in chronic rhinosinusitis

Abstract Background: Chronic rhinosinusitis (CRS) is characterized according to the presence or absence of nasal polyps (NPs) and displays nasal microbiota dysbiosis. However, optimal sampling methods of the nasal microbiome in CRS have not been identified. We therefore aimed to assess the microbial composition in patients with CRS, comparing different sampling methods (swab and tissue biopsy), tissue types (uncinate tissue and NP), and disease subtypes.Methods: Samples were obtained by swabbing the middle meatus and taking a biopsy of uncinate tissue (UT) in 8 patients with CRS with NP (CRSwNP), 6 patients with CRS without NP (CRSsNP), and 8 controls. NPs were also harvested in CRSwNP. Extracted DNA samples were analyzed by 16S rRNA gene amplicon sequencing.Results: The microbiome diversity did not significantly differ between disease subtypes in nasal swabs or UT samples. However, a principal coordinates analysis based on weighted UniFrac distances revealed a greater interpersonal variance for nasal swabs than for UT. UT samples presented with a distinct pattern and composition in CRSwNP compared to CRSsNP or control. Compared to UT, NP revealed a unique microbiome profile with significantly less bacterial diversity. Prevotella was the most abundant genus in the UT regardless of the disease subtype and its prevalence was significantly reduced in NP. Prevotella abundance was negatively correlated with disease severity as measured by Lund-Mackay scoring.Conclusion: Tissue samples are better specimens than nasal swabs for assessing the microbiomes of CRS patients. Microbiomes of NP tissues revealed an association with clinical severity of CRSwNP.