Abstract
INTRODUCTION: Microbiome-targeted treatments have been investigated in atopic dermatitis (AD). We aimed to investigate the tolerability and efficacy of probiotic Lactobacillus lactis lysate cream in AD. METHODS: A total of 13 patients with mild-to-moderate AD were treated with differently concentrated probiotic creams (3, 10, and 30%) for 4 weeks. The severity of AD [Eczema Area and Severity Index (EASI) and Investigator Global Assessment (IGA)], epidermal barrier function (TEWL), and the impact of AD [Dermatology Life Quality Index (DLQI), Patient-Oriented Eczema Measure (POEM), Atopic Dermatitis Control Tool (ADCT), and pruritus and sleep disturbance visual analog scale (VAS)] were measured at baseline (BL) and at 4 and 8 weeks. Comprehensive clinical patient data and laboratory values, including blood eosinophil count, total serum IgE levels, and specific IgEs to aeroallergens, were obtained. RESULTS: Comparison of the treatment groups and longitudinal comparisons at various time points showed no significant differences regarding AD severity (EASI, p = 0.76, CI: 0.65-1.00), epidermal barrier dysfunction (TEWL, p = 0.37, CI: 0.19-0.73), or patient-reported subjective impact of AD (DLQI, p = 0.76, CI: 0.65-1.00; POEM, p = 0.76, CI: 0.35-0.88; ADCT, p = 0.72, CI: 0.65-1.00; pruritus VAS 0.67, CI: 0.55-1.00; sleep disturbance VAS, p = 1.00, CI: 0.79-1.00) between different probiotic lysate concentrations and placebo. The probiotic lysate cream was well-tolerated, and there were no significant adverse effects. The limitations of the study were the small patient cohort and group sizes. There was also a relatively short follow-up, and no evaluation of long-term effects was conducted. DISCUSSION: In our patient cohort, topical probiotic L. lactis lysate cream showed good tolerability, but it did not show efficacy in the treatment of mild-to-moderate AD. Although topical probiotics have been reported to be effective in a limited number of studies, more placebo-controlled clinical studies are needed to explore their potential role in the treatment of AD. CLINICAL TRIAL REGISTRATION: https://eudract.ema.europa.eu, Identifier EudraCT 2020-000514-15.