A Comparison of the Bacterial Nasal Microbiome in Allergic Rhinitis Patients Before and After Immunotherapy.

Objectives/hypothesis: Recent research has examined the nasal microbiome in rhinosinusitis and nondiseased states. Given immunologic alterations in allergic rhinitis (AR) and after allergen immunotherapy (IT), we evaluated the nasal microbiome in these conditions.

Study Design: Cross-sectional comparison.

Methods: In this cross-sectional study, nasal swabs for microbiome analysis were collected from three patient groups: IT-naïve AR patients, AR patients undergoing IT for greater than 12 months, and a control group without sinonasal inflammatory disease.

Results: Nasal swabs were successfully collected for 14 IT-naïve AR patients, 20 post-IT patients, and 17 controls. The α diversity showed a statistical difference in evenness but not in richness amongst samples, whereas the β-diversity was significantly different between groups. Corynebacterium and Staphylococcus were the most prevalent bacteria across all groups.

Conclusions: β-diversity was found to be significantly different across the three groups, but the AR groups were found to be more similar to each other than to the controls. Although there is symptomatic improvement in the AR group undergoing IT, the microbiome does not appear to transition to a healthy microbiome composition.

Level Of Evidence: 4 Laryngoscope, 2020.