Cystic fibrosis (CF) patients have more bacteria but lower bacterial diversity in their lungs than people without CF — yet bacterial diversity diminishes with age in CF patients, a large multicenter study found.

The study, “Airway microbiota across age and disease spectrum in cystic fibrosis,” appeared in the European Respiratory Journal.

CF is characterized by recurrent airway infection, inflammation and progressive decline in lung function. Genetic mutations in these patients induce a salt imbalance, leading to airway surface dehydration and the buildup of thick and sticky mucus. This creates an ideal habitat for bacteria, which is why chronic bacterial lung infections are the leading cause of death in CF.