Non-invasive detection of pediatric atopic dermatitis based on fecal microbiota and metabolite profiles: a diagnostic approach.

Background: Atopic dermatitis (AD) is a common chronic skin inflammation, which affects 15-20% of children worldwide. Gut microbiota and its metabolites are crucial modulators of the "gut-skin axis" in atopic dermatogenesis. However, systematic investigations integrating microbiome and metabolome profiling in mild-to-moderate pediatric AD remain limited. Objectives: To characterize gut microbiota and metabolic profiles in children with mild-to-moderate AD versus healthy controls, and to identify potential biomarkers and mechanistic pathways involved in disease pathogenesis. Methods: This single-center case-control study investigated 53 children diagnosed with AD and 16 healthy participants, and collected their fecal samples for microbial and metabonomic analysis. Results: Mild-moderate pediatric AD patients exhibited significantly increased gut microbial richness and distinct β-diversity compared to controls (PERMANOVA, R²=0.025, Conclusion: Mild-to-moderate pediatric AD is characterized by distinct gut microbiota dysbiosis and metabolic alterations involving lipid metabolism. Cross-sectionally identified microbial features show exploratory associations with AD status, but causal inference is not possible. These hypothesis-generating findings support further investigation of the gut-skin axis in AD development and provide a rationale for future interventional studies targeting the microbiome and metabolome.