Distinct microbial and functional alterations across skin sites and disease severity in pediatric atopic dermatitis: a prospective study

BackgroundAtopic dermatitis (AD) is a chronic inflammatory skin condition frequently associated with microbial dysbiosis.ObjectiveThis study examined the diversity, composition, and functional profiles of the skin microbiome in children with varying degrees of AD in different skin regions.MethodsSkin samples were collected from 12 AD patients and 12 healthy controls. Genomic DNA underwent shotgun metagenomic sequencing to analyze alpha and beta diversity, taxonomic composition, and functional profiles, including the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), virulence factors and pathogen-host interactions (PHI).ResultsSignificant differences were observed in Shannon’s diversity index and Chao1 diversity index between severity groups (p = 0.007 and 0.004). Cluster analysis revealed partial clustering by severity, with significant differences between mild and moderate groups (p = 0.042) and between moderate and severe groups (p = 0.036). Staphylococcus and Streptococcus dominated the abundance profile in AD samples. Functional analysis revealed alterations in epidermal microbial activity during AD onset and across different severity levels.ConclusionPediatric AD involves site- and severity-specific microbial shifts. This functional dysregulation and enrichment of virulence factors may push barrier dysfunction and inflammation, suggesting that the microbiome is a critical target for future therapies.