Skin and gut microbiome in atopic dermatitis: Mechanisms and therapeutic opportunities

The pathogenesis of atopic dermatitis (AD) comprises a combination of genetic, immune, and microbial factors. An imbalance in skin and gut microbiota composition, termed dysbiosis, may contribute to AD pathogenesis and severity through overgrowth of pathogenic microbes and suppression of healthy commensal colonization. These, in turn, promote barrier disruption and pro-inflammatory responses. The skin and gut microbiota composition plays crucial roles in AD, namely as early predictive biomarkers of AD onset; indicators of treatment response; and as future novel therapeutics such as probiotics, fecal, and skin microbiota transplantation. Such interventions aim to directly "reset" and restore a healthy microbial equilibrium, thereby fundamentally repairing barrier function, regulating immune homeostasis, and establishing new adjunctive pathways for the long-term management of AD.