Oral Postbiotic (VMK223) Supplementation Is Associated with Improved Instrumental Skin Appearance Parameters in Healthy Women Aged 40-55 Years: A Randomized, Double-Blind, Placebo-Controlled Trial

Introduction: Skin aging in midlife women is influenced by intrinsic aging processes, hormonal transitions, and systemic factors that affect skin structure, hydration, and elasticity. Increasing interest has emerged in oral interventions targeting the gut-skin axis as a complementary strategy to topical skincare. However, clinical evidence linking postbiotic supplementation to objective changes in skin appearance remains limited. Methods: In this randomized, double-blind, placebo-controlled trial, 34 healthy women aged 40-55 years were assigned to receive either an oral postbiotic supplement (VMK223, 500 mg/day) or placebo for 12 weeks. Objective skin appearance parameters, including pore appearance, melanin levels, acne severity, wrinkle depth, hydration, and elasticity, were assessed at baseline and at weeks 4, 8, and 12 using a standardized, noninvasive skin analysis device. A composite skin quality score integrating pores, melanin, acne, and wrinkles was developed as an exploratory outcome. Results: Overall, 29 participants completed the study (VMK223: n = 16; placebo: n = 13). Compared with placebo, VMK223 supplementation was associated with significantly greater improvements across multiple skin parameters over time. At week 12, the VMK223 group showed greater reductions in wrinkle depth (28.0% versus 4.4%, p < 0.001), pore appearance (22.0% versus 8.2%, p < 0.001), acne severity (15.9% versus 7.0%, p < 0.01), and melanin levels (11.5% versus 0.9%, p < 0.05), alongside greater increases in skin hydration (28.3% versus 11.0%, p < 0.001), and elasticity (26.8% versus 5.8%, p < 0.001). The composite skin quality score improved by 20.9% in the VMK223 group compared with 5.6% in the placebo group (p < 0.001). Improvements were progressive and most pronounced after 8-12 weeks. Oral postbiotic supplementation for 12 weeks was associated with significant improvements in multiple objective skin appearance parameters in healthy women aged 40-55 years. Conclusions: These findings support the potential role of postbiotics as a systemic, adjunctive approach for improving visible skin quality. Further studies incorporating biological markers are warranted to elucidate underlying mechanisms. Infographic available for this article. Gov identifier: NCT04267731.