Acid blockade is a frequent treatment for cystic fibrosis patients (CF). However, there are growing worries regarding its putative role in the pathogenesis of lung infections. The researchers wanted to see if acid blocking changes the esophageal and respiratory microbiota, causing dysbiosis and inflammation. They conducted a cross-sectional study on children with cystic fibrosis who were either on acid blockade or were not. The microbiome was studied using samples from the gastrointestinal and respiratory systems. To account for the various sampling sites per participant, a random subject intercept was introduced. A total of 25 people were enrolled, with 44 percent of them being girls and a median age of 13.8 years. The levels of beta diversity, total bacterial burden, and alpha diversity were comparable across anatomic compartments, the upper gastrointestinal system, and respiratory samples. In the entire group, IL-8 levels were higher in the distal compared to the proximal oesophagus. IL-8 concentrations in the distal oesophagus were identical in patients on and off acid blocking, but considerably higher in the proximal oesophagus of participants on treatment.

Based on these findings, acid blockade therapy does not appear to affect the microbiome of the aerodigestive tract in children with cystic fibrosis, implying a complex interaction between these medications and the bacterial composition of the esophagus and lung.