The Efficacy of Lactobacillus ferment Lysate-Derived Prebiotics in Mist and Serum Form on Skin Inflammation: A Two-Week Prospective Study

Background: Prebiotics derived from Lactobacillus ferment lysate support beneficial cutaneous microbiota, helping to reduce inflammation and strengthen the epidermal barrier. However, evidence assessing their topical efficacy in distinct formulations remains limited. Objective: To evaluate the efficacy of Lactobacillus ferment lysate-derived prebiotics in mist and serum formulations, applied twice daily, on facial erythema as an indicator of skin inflammation. Methods: Twenty healthy adults (15 women, 5 men; aged 29-46 years) participated in a two-week prospective study using Lactobacillus fersment lysate prebiotic mist and serum, both applied twice daily. Participants followed a standardised skincare regimen including a gentle cleanser and SPF50 sunscreen, with no other products permitted. Facial erythema was objectively measured before and after intervention using a Quantificare Life Viz® Mini 3D camera to determine red area percentage (erythema index). Imaging was standardised with controlled temperature and humidity, consistent morning imaging times, device calibration, fixed subject positioning and Quantificare’s integrated cross-polarised LED lighting. Results: All participants exhibited visible and quantifiable reductions in facial redness after two weeks. The mean red area decreased by 28.6% ± 6.5% compared with baseline (p < 0.01). No irritation or adverse reactions were reported. Conclusion: Twice-daily application of Lactobacillus ferment lysate-derived prebiotic mist and serum significantly reduced facial erythema within two weeks. These findings support the role of topical prebiotics in maintaining microbiome balance and reducing cutaneous inflammation.