Methods
Saliva samples collected from 143 children (6-17 yrs) with moderate-to-severe asthma across four European countries (the Netherlands, Germany, Spain, and Slovenia) as part of the SysPharmPediA cohort were subjected to 16S rRNA sequencing. Microbiome was compared using global diversity (α and β) between two groups of participants based on inhaler devices (MDI (n=77) and DPI (n=65)) and differential abundance was compared using the Analysis of Compositions of Microbiomes with the Bias Correction (ANCOM-BC) method.