The role of skin dysbiosis in atopic dermatitis

The cutaneous microbiota contributes to skin barrier function, ensuring effective protection against pathogens and contributing to the maintenance of epidermal integrity. Dysbiosis is frequently present in atopic dermatitis (AD), a chronic inflammatory disease associated with skin barrier defects. Dysbiosis is associated with reduced bacterial diversity and marked Staphylococcus aureus colonization, which is favoured in the case of certain local AD-specific properties such as reduced skin acidity, eased bacterial adhesion and decreased antimicrobial peptide production. Furthermore, S. aureus-associated skin dysbiosis, via the production of staphylococcal virulence factors, may also participate in the immunopathology of AD by altering the epidermal barrier and inducing an inflammatory response. However, there are currently no arguments for recommending screening for, and treatment of S. aureus-associated dysbiosis outside the setting of cutaneous superinfection. Nonetheless, modulation of the skin microbiota may hold promise for AD management. Here, we describe the relationships that exist between the skin microbiota and AD.