Metabolomic signatures associated with probiotic use in atopic dermatitis: An exploratory study

Atopic dermatitis (AD) is a chronic inflammatory skin disorder modulated by complex interactions between immune dysregulation and compromised skin‑barrier integrity, in which the gut microbiome may play a role in the natural course of the disease. Therefore, by influencing the composition of the gut microbiome, one of the effective therapeutic options for AD treatment may include probiotics. To extend our knowledge of probiotics and how gut microbiome may affect disease evolution, this exploratory study assessed the systemic effects of a 90‑day probiotic supplementation in AD patients, integrating clinical assessment, serum cytokine profile, and GC-MS-based metabolomics. Significant clinical improvement has been observed after probiotic intake, with reductions in treated patients of the main clinical indices to assess the AD severity (i.e., SCORAD, EASI, and DLQI). These patients also showed reduced serum levels of pro-inflammatory cytokines (i.e., IL-1β, IL-6, and IL-8), indicating attenuation of systemic inflammation. Moreover, metabolomic analysis revealed a marked change between baseline (T0) and post-treatment (T1) serum profiles of AD patients, consistent with a reduction in inflammatory signalling and improved clinical status. These findings highlight meaningful metabolic remodelling associated with probiotic supplementation and support its potential as an adjunctive therapy in AD.