Even in a small sample of patients with CRS, non-taster T2R38 genotype appears to predict the presence of culturable bacteria colonising the sinus cavity at the time of surgery for their condition. A genetic link to patients more likely to become infected is likely.
Objective
The role of the microbiome in the etiology of chronic rhinosinusitis (CRS) is still in debate. Reductions in richness and diversity have been implicated in CRS; however, limited knowledge exists regarding the impact of the severity of disease on the microbiome. The associations between constituents of the microbiome and the degree of mucosal inflammation and tissue eosinophilia are described.
Methods
A cross‐sectional study of CRS and non‐CRS patients who underwent endoscopic sinus surgery was performed. Sinus mucosal biopsies were assessed for the degree of inflammation and tissue eosinophilia. Middle‐meatal swabs were subjected to 16S rRNA gene sequencing, which quantified the prevalence, mean relative abundance, richness, and diversity. Comparisons between the microbiome at the genus level and degree of inflammation (absent, mild, moderate, severe) and tissue eosinophilia (absent, < 10, 10–100, > 100 per high‐powered field) were performed.
Results
Eight‐nine patients (52.8 ± 14.21 years, 64.0% male) were assessed. Of those, 52 had CRS and 37 were controls. Corynebacterium and Staphylococcus were the most abundant genera in both the CRS (29% and 16%) and non‐CRS groups (40% and 20%). Richness decreased in more severely inflamed patients (23.2 ± 13.9 vs. 18.1 ± 16.1 vs. 16.8 ± 12.3 vs. 14.7 ± 10.9; P < 0.01), as did diversity (1.4 ± 0.7 vs. 1.2 ± 1.0 vs. 1.2 ± 0.8 vs. 0.9 ± 0.7; P = 0.05). Richness was associated with higher tissue eosinophilia (23.2 ± 13.9 vs. 19.3 ± 17.2 vs. 15.9 ± 11.6 vs. 13.4 ± 6.6; P < 0.01).
Conclusion
The loss of richness and diversity seen in the CRS microbiome appears to be a product of severity of inflammation and tissue eosinophilia. Whether this dysbiosis is causative or a result of the disease with impaired epithelial integrity requires ongoing research.
Level of Evidence
4
Laryngoscope, 129:1265–1273, 2019
The culturable bacterial community has little impact on histopathology in CRS. While more sensitive tests may detect bacteria in the sinuses, the impact of the simple "culturable" bacteria on the underlying pathologic process is limited. Changes, such as subepithelial fibrosis, suggest colonization may lead to undesirable local mucosal damage and remodeling.
Osteitis in CRS is associated with the degree of eosinophilia and as a independent process it was associated with the need for a course of systemic corticosteroid over a 12-month period, but did it not affect overall disease control.
Key Points
Culturable bacterial colonization is similar between type 2 CRS phenotypes
Staphylococcus aureus coinfection is similar between eosinophilic CRS and CCAD
Patients with CCAD were younger, consistent with current knowledge of the disease
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.