The Skin Microbiome Differs with Age in Atopic Dermatitis
Sunday, March 6, 2016: 2:00 PM
Petree Hall D (Convention Center)
Baochen Shi, PhD, , , , , ,
Rationale: Pediatric and adult atopic dermatitis (AD) have different disease manifestations. The skin microbiome is thought to be critical in driving disease development. Whether the skin microbiome in young AD children is different from adults is unknown.

Methods: We collected swabs from lesional and non-lesional skin of the volar forearm of 128 AD patients and 68 healthy subjects. We compared the skin microbiome of AD patients with healthy individuals in different age groups (2-12 and 13-62) using 16S rRNA gene sequencing. We analyzed correlations between the microbiome and age and investigated gene functions encoded in microbial genomes.

Results: We found that the healthy skin microbiome was significantly different between young children and adults in microbial diversity and in relative abundance of  prevalent bacterial genera. Compared to the diverse microbial community on healthy skin, AD skin microbiome was dominated by Staphylococcus species at all ages. Importantly however, shifts in the AD microbiome compared to the healthy microbiome were different between young children and adults. We identified distinct clusters of childhood-associated (represented by Streptococcus), adult-associated (Propionibacterium and Corynebacterium), and AD-associated skin bacteria. By analyzing 46 genomes representing major species in the clusters, we further identified specific functional profiles among these clusters.

Conclusions: Childhood-associated skin bacteria Streptococcus are replaced by adult-associated lipophilic commensals that associate with sebum production at puberty. Pathways unique to Propionibacterium and Corynebacterium, including porphyrin and chlorophyll metabolism, may provide additional protection for skin health in adults. Our findings suggest that pediatric and adult AD are driven by different microbial influences.