Association of corticosteroid inhaler type with saliva microbiome in moderate-to-severe pediatric asthma Background Metered dose inhalers (MDIs) and dry powder inhalers (DPIs) are common inhaled corticosteroid (ICS) inhaler devices. The difference in formulation and administration technique of these devices may influence oral cavity microbiota composition. We aimed to compare the saliva microbiome in children with moderate-to-severe asthma using ICS via MDIs versus DPIs. 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. Results No significant difference was observed in α-diversity between the two groups. However, β-diversity analysis revealed significant differences between groups using both Bray-Curtis and weighted UniFrac methods (Adjusted p-value=0.015 and 0.044, respectively). Significant differential abundance between groups, with higher relative abundance in the MDI group compared to the DPI group, was detected at the family level [Carnobacteriaceae (Adjusted p=0.033)] and at the genus level [ Granulicatella (Adjusted p=0.021) and Aggregatibacter (Adjusted p=0.011)]. Conclusion Types of ICS devices are associated with different saliva microbiome composition in moderate-to-severe pediatric asthma. The causal relation between inhaler types and changes in saliva microbiota composition needs to be further evaluated, as well as whether this leads to different potential adverse effects in terms of occurrence and level of severity.

Background: The prevalence of food allergies (FA) in children increased rapidly at the turn of the century. The EuroPrevall study identified Germany as a country with very high prevalence of FA at that time. Using two large German birth cohorts we provide an update of the status quo ten years later. Methods: KUNO Kids and Ulm SPATZ Health studies are two ongoing prospective birth cohorts. Information on FA was obtained by questionnaires at birth and after 6, 12 and 24 months. Univariate logistic regression analyses were performed to investigate risk factors during pregnancy, birth and early childhood. Results: In 1139 and 1006 children from KUNO Kids and SPATZ the point prevalence of parent-reported FA symptoms at the ages of 1 and 2 years was 13.2% and 13.9 % in KUNO Kids. Doctor’s diagnosed FA at 1 and 2 years was 2.4% and 2.7% in KUNO Kids and 2.3% and 3% in SPATZ. Cow’s milk and citrus fruits were most frequently suspected by parents to cause FA symptoms. Atopy in the child was associated with a higher frequency of FA at any time, whereas atopy in first degree relatives was only associated with FA at year 1. Smoke exposure during pregnancy was a risk for FA at age 2. Conclusion: The prevalence of food allergy seems to have plateaued in the last 10 years in Germany. FA is often suspected by parents but only rarely diagnosed by oral food challenge. Risk factor analysis may help to establish personalized health approaches.