Correct antibiotic dosing could preserve lung microbial diversity in cystic fibrosis

Children and young adults with cystic fibrosis (CF) whose lung infections were treated with suboptimal doses of antibiotics had fewer changes in lung microbial diversity during the IV treatment, and their microbial diversity levels were higher 30 days later, a multi-institutional study that includes Children's researchers shows. By contrast, patients who were treated with therapeutic doses had greater decreases in lung microbial diversity and significantly lower diversity levels when the antibiotic treatment ended as well as 30 days later. "With the subtherapeutic treatment group, this could represent a 'basement effect' where it is harder to decrease diversity when it is already low to start. Also, patients in the subtherapeutic group had more advanced disease than those in the therapeutic group, which may influence the findings," explains Andrea Hahn, M.D., MS, an infectious disease specialist at Children's National Health System and the study's lead author. The findings, published online Feb. 22, 2019, in Scientific Reports, clearly establish the importance of the interplay between baseline microbial diversity and lung function and have the potential to improve clinical practices, the research team writes.