Comparing the nasal bacterial microbiome diversity of allergic rhinitis, chronic rhinosinusitis and control subjects

Until now, the microbiome of the nasal cavity and its contribution to nasal mucosal disease has remained poorly understood. The advent of cultivation-free molecular methods makes it possible to characterize the total microbiome of the nasal cavity. We sought to assess the microbial diversity and composition of the middle meatus in allergic rhinitis (AR) patients, chronic rhinosinusitis patients without polyps (CRSsNP) and a control population to determine the microbiota associated with the pathogenesis of AR and CRSsNP.

Microbial characterization was determined using 16S rRNA gene sequencing of 122 nasal swabs collected from patients with AR (n = 52) and CRSsNP (n = 37), and from healthy controls (n = 33).

There was no difference in nasal microbiome richness and diversity among the three groups, and the dominant phyla were similar among three groups including Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. However, Spirochaetae abundance was significantly higher in AR than in the control group after FDR correction (FDR p = 0.021). At the genus level, although there was no statistical significance after FDR correction, there was a trend that Pseudomonas and Peptostreptococcaceae abundance were higher in AR than in controls (p = 0.005, p = 0.005) and CRSsNP (p = 0.023, p = 0.034); Lactobacillus abundance was lower in AR than in controls (p = 0.021); Moraxella abundance was lower in CRSsNP than in controls (p = 0.006); Haemophilus abundance was higher in CRSsNP than in AR (p = 0.003) but lower in AR than in controls (p = 0.018).

These results suggested that microbial dysbiosis may play a role in the pathogenesis of heterogeneous nasal mucosal inflammation.