Sputum microbiota in adults with CF associates with response to inhaled tobramycin

Individuals with cystic fibrosis experience chronic lung infections with Pseudomonas aeruginosa. Anti-pseudomonal antibiotics such as inhaled tobramycin improves lung function and quality of life of chronically infected patients. We hypothesized that inhaled tobramycin has additional off-target effects beyond P. aeruginosa and that baseline microbiome prior to initiation of therapy is associated with subsequent patient response. One hundred and fifty-one sputum samples were collected from 41 patients before and after inhaled tobramycin initiation. Targeted 16S amplicon sequencing was used to assess the sputum microbiome. Patients demonstrated no significant changes in the microbiome pre vs post treatment initiation. However, patients that demonstrated improvements in lung function post inhaled tobramycin had a higher abundance of Staphylococcus in pre-therapy baseline samples suggesting a potential biomarker to predict patient response.