Association of the sinonasal bacterial microbiome with clinical outcomes in chronic rhinosinusitis: a systematic review

Background: The association between sinonasal microbiome and clinical outcomes of patients with chronic rhinosinusitis (CRS) is unclear. We performed a systematic review of prior studies evaluating the CRS microbiome in relation to clinical outcomes. Methods: Computerized searches of PubMed/Medline, Cochrane, and EMBASE were updated through October 2019 revealing a total of 9 studies including 244 CRS patients. A systematic review of the literature was performed, including data extraction focusing on sample region, sequencing platforms, predominant organisms, and outcomes measures. Results: Nine criterion-meeting studies included 244 CRS patients, with varied results. Eight studies used 16s–ribosomal RNA (16s-rRNA) gene sequencing to assess the sinonasal microbiome and 1 used 16s-rRNA PhyloChip analysis. Seven studies used Sino-Nasal Outcome Test scores, 1 applied another CRS symptom metric, and 1 used need for additional procedures/antibiotics as the primary clinical outcome. Three studies suggest that baseline abundance of phylum Actinobacteria (specifically genus Corynebacterium) was predictive of better surgical outcome. One study found C. tuberculostearicum was positively correlated with symptom severity. Another study revealed genus Escherichia was overrepresented in CRS and had positive correlation with increased symptom scores. In addition, 1 study identified Acinetobacter johnsonii to be associated with improvement in symptom scores while supporting Pseudomonas aeruginosa as having a negative impact on quality of life. Conclusion: Microbiome data are varied in their association with clinical outcomes of CRS patients. Further research is required to identify if predominance of certain microbes within the microbiome is predictive of CRS patients’ outcomes.