Topical Live and Heat‐Killed Probiotics for Photoaging Prevention: A Meta‐Analysis

Background The skin microbiome plays a crucial role in maintaining healthy skin, and imbalances in this microbial community, often caused by aging and environmental factors like UV radiation, are linked to photoaging. Topical probiotics may help prevent it. Methods Following PRISMA 2020 guidelines, we systematically reviewed and meta‐analyzed studies assessing topical probiotics for photoaging prevention in adults and the elderly. Risk of bias was evaluated using RoB 2 and ROBINS‐I tools. Data were analyzed with a random‐effects model, and heterogeneity was assessed via I 2 statistics. Results From 2228 articles, five studies were included in the systematic review and two in the meta‐analysis, comprising 210 participants. The review showed significant improvements in aging signs—such as radiance, hydration, wrinkles, pigmentation, erythema, texture, firmness, smoothness, elasticity, and density—in probiotic‐treated groups. The meta‐analysis revealed trends toward improved skin hydration and wrinkle reduction in the probiotic group though these were not statistically significant ( p > 0.05). No significant adverse effects were reported. Conclusions Topical probiotics represent a promising adjunctive strategy for preventing and mitigating photoaging. However, well‐designed, preclinical, and large‐scale clinical studies are still required to elucidate their mechanisms of action, determine optimal formulations, and confirm their long‐term efficacy and safety in the prevention of photoaging.