Modulating the Gut–Skin Axis in Dermatological Diseases: Mechanisms and Clinical Applications of Probiotics, Prebiotics, Synbiotics, and Postbiotics

The review explores the gut–skin axis, highlighting its role in dermatological diseases like atopic dermatitis, acne, rosacea, and psoriasis through immune, metabolic, and neuroendocrine pathways. It evaluates probiotics, prebiotics, synbiotics, and postbiotics as modulators of this axis. Evidence suggests that certain Lactobacillus and Bifidobacterium strains improve skin barrier function and inflammatory responses, particularly in pediatric atopic dermatitis. The efficacy in acne, psoriasis, and rosacea is moderate and variable. Prebiotics and synbiotics show positive effects on microbial balance, while postbiotics are emerging as safe therapeutic options. The review emphasizes the need for more targeted clinical trials to establish the precise role of these interventions in dermatology.