The Skin–Gut Connection: Oral Probiotic Supplementation Enhances Skin Well-Aging in a Double-Blind, Randomized, Placebo-Controlled Clinical Study

The concept of well-aging focuses on maintaining skin health and appearance through cosmetic and nutritional strategies. Among these, probiotics have gained interest in their potential to enhance skin health, hydration, and barrier. This randomized, placebo-controlled clinical study evaluated the efficacy of a probiotic-based dietary supplement in improving key skin aging parameters. Sixty-six participants received either the active or the placebo supplement for 56 days, followed by a 28-day follow-up to assess the lasting effect. Skin assessments included 3D profilometry, high-frequency ultrasound, moisturization, transepidermal water loss (TEWL), and oxidative stress evaluation. After 28 and 56 days, the probiotic group showed significant improvements compared to placebo, including reduced wrinkle depth (–10.4% at T28; –15.0% at T56) and roughness (–4.3% at T28; –6.1% at T56), increased dermal thickness (+2.5%) and density (+3.31%), enhanced superficial (+11.9% at T28; +16.5% at T56) and deep moisturization (+4.5% at T56), and lower TEWL (–9.7% at T28; –14.5% at T56). Skin antioxidant capacity also increased (+50.3% at T56). Skin improvements were maintained after the follow-up period, supporting the role of probiotics in long-term skin health. These findings reinforce the role of probiotics in well-aging, demonstrating their ability to positively influence skin health through the gut-skin axis even beyond the supplementation period.