438 Differences between the microbiome of lesional and non-lesional skin in atopic dermatitis

Abstract

Atopic dermatitis (AD) is a chronically relapsing inflammatory skin disease. It is still unclear whether and how previously observed changes in the microbiota in AD patients (a reduction of the local diversity and an increase in Staphylococcus spp.) influence the severity of AD flairs. Here, we address the differences in the microbiome of lesional and neighboring non-lesional skin in AD patients as compared to healthy controls. AD status was monitored and documented by a physician using SCORAD. The microbiome in skin swab samples of patients (N=11, one lesional site and an adjacent non-lesional site) and healthy controls (N=7) was sequenced using amplicon based 16S analyses of hyper variable regions V1 to V3. The global microbiome of AD patients’ skin samples is significantly different from that of healthy donors’ skin. We confirmed that the microbiota diversity in AD lesional skin samples is significantly lower than that of AD non-lesional, and both lower than healthy donors’ skin. This is mainly due to significantly higher frequency of the most abundant species, of the genus Staphylococcus, in AD lesional samples. However, we see no global microbiome difference between AD lesional and non-lesional skin samples. Nevertheless, there are significant differences in the frequencies of several species, in particular of the Staphylococcus genus, between AD lesional and non-lesional skin samples. Our results confirm and extend the current knowledge about AD related microbiome changes. We are currently investigating whether the skin microbiome changes in AD, with respect to lower diversity and increased Staphylococci counts, are a cause or result of the AD status. One option for future intervention or treatment could be the “self-microbiome transplantation”, possibly giving rise to reduction of an acute flair.