Sinonasal and gastrointestinal bacterial composition and abundance are stable after 1 week of once-daily oral antibiotic treatment for chronic rhinosinusitis.

Antibiotic prescription for CRS should be further investigated because of preliminary evidence of poor sinonasal drug penetration, unproven efficacy, and the potential impact of dysbiosis in the sinuses and off-target sites. Further studies should consider distinguishing the presence of DNA from viable and nonviable bacteria.