Healthy volunteers get bronchoscopy to uncover steroid secrets

This study looks at how a common asthma inhaler (fluticasone propionate) changes gene activity and cell types in the lungs of 30 healthy adults. Participants will take the inhaler for 4 weeks and have a bronchoscopy (a camera down the airway) to collect samples. The goal is to understand the drug's effects on normal lungs, not to treat any disease.