Microbiome of the Middle Meatus, Tonsils, and Adenoids in Pediatric Chronic Rhinosinusitis

Abstract Objective Pediatric chronic rhinosinusitis (PCRS) is a common condition with a significant impact on quality of life. This study compares the microbiome of pediatric patients with and without chronic rhinosinusitis. Study Design Single‐center, prospective, quantitative case‐control. Setting Metropolitan. Methods Patients undergoing adenoidectomy for PCRS (subjects, n = 20) or obstructive sleep apnea (controls, n = 20) were recruited. 16S ribosomal RNA sequencing was performed on the right middle meatus (MM), adenoid, and palatine tonsil samples from each patient. Alpha diversity was measured by the Simpson's diversity index, beta diversity was measured by the Bray‐Curtis dissimilarity index, and the differential abundance of bacteria genera was analyzed. Results There were 40 adenoid, 40 tonsil, and 37 MM samples analyzed. There was no significant difference in alpha diversity between controls and subjects. Tonsils were significantly more diverse than the adenoids, which were more diverse than the MM ( P < .001). There was no difference in bacterial composition between controls and subjects, but the composition of the 3 sites were significantly different ( P < .001). The dissimilarity in bacterial composition between the adenoid and MM sites was larger in the control group than in the subject group. Conclusion There were significant differences in alpha diversity and bacterial composition between the anatomic 3 sites; however, there was no difference between the controls and subjects. The larger dissimilarity in bacterial composition between adenoid and MM sites in controls compared to subjects suggests there may be colonization of the MM by the adenoid in PCRS patients.