The skin microbiome plays a central role in maintaining cutaneous homeostasis, and its disruption has been implicated in a wide range of inflammatory and degenerative skin disorders. This review critically evaluates the current evidence on topical probiotics in dermatology, integrating microbiological mechanisms, formulation strategies, and translational and regulatory challenges within a single framework—an angle that remains insufficiently addressed in previous reviews. A targeted search of PubMed and ScienceDirect (2009–2025) was conducted to identify relevant original studies. The results suggest that topical probiotics may promote skin health through three broad, interconnected axes: (i) modulation of host responses (e.g., inflammation, immune signaling, and oxidative stress); (ii) microbial ecology and pathogen control (e.g., competition, acidification, and antimicrobial metabolite production); and (iii) support of barrier function and tissue repair (e.g., lipid metabolism, re-epithelialization, and extracellular matrix remodeling). Efficacy appears to depend strongly on strain specificity, formulation design, and microbial viability during storage and application. In addition to conventional dosage forms, advanced platforms—hydrogels, microgels, microparticles, and microneedle-based systems—have been investigated to improve stability and local delivery. Promising preclinical and clinical results have been reported for acne, wound healing, skin barrier repair, and anti-aging applications. Nevertheless, major translational challenges remain, including limited standardization, instability of live microorganisms, insufficiently representative experimental models, and regulatory uncertainty. Overall, topical probiotics represent a promising microbiome-based strategy in dermatology, but robust clinical validation and formulation optimization are still needed to support broader clinical implementation.
Bonadei et al. (Wed,) studied this question.