Table 1 Participant selection criteria

• The patient is willing and able to give informed consent

• The patient must be ≥ 18 years

• The patient must have an established diagnosis of CF (one or more of the following), sweat chloride > 60 mEq/L and/or presence of two CF-causing mutations

• The patient must have chronic symptoms of rhinosinusitis according to the criteria of the European Position Paper on Rhinosinusitis

• The patient scores greater ≥ 7 on their SNOT-22 questionnaire

• The patient has ever tested positive for the bacteria Mycobacterium tuberculosis

• The patient is currently using a nasal rinse protocol

• The patient has undergone sinus surgery within 6 months

• The patient suffers from nasal bleeding

• The patient is currently undergoing systemic antibiotic therapy for infective exacerbation

• The patient is using overnight oxygen via nasal cannula

• The patient is participating in another clinical trial or has done so within the last 30 days

• The patient has a known allergy to bee products