Children with atopic dermatitis show clinical improvement after Lactobacillus exposure

Summary Background The role of probiotics in the treatment of atopic dermatitis (AD) is not clearly established. Further clinical trials with new probiotic formulations are warranted. Objectives To assess the effects of Lactobacillus paracasei (LP) and Lactobacillus fermentum (LF), and their mixture on the disease severity, quality of life, and immune biomarkers of children with AD. Method A double‐blind, prospective, randomized placebo‐controlled study was conducted on 220 children aged 1–18 years with moderate‐to‐severe AD (Trial number: NCT01635738). The children were randomized to receive LP, LF, LP + LF mixture, and placebo for 3 months. Changes in severity scoring of atopic dermatitis (SCORAD), Family Dermatology Life Quality Index (FDLQI), and Children's Dermatology Life Quality Index (CDLQI) scores in the different groups and at different visits were evaluated. Skin prick tests, levels of IgE, IFN‐γ, IL‐4, TGF‐β, and TNF‐α, and urine biomarkers were also evaluated. Results Children who received LP, LF, and LP + LF mixture showed lower SCORAD scores than the placebo group ( P < 0.001), and this difference remained even at 4 months after discontinuing the probiotics. The FDLQI and CDLQI scores were lower in the LP, LF, and LP + LF mixture group than in the placebo group ( P = 0.02 and 0.03). IgE, TNF‐α, urine eosinophilic protein X, and 8‐OHdG levels decreased, whereas IFN‐γ and TGF‐β increased in the probiotic groups, but these did not reach statistical significance except for IL‐4 ( P = 0.04). In subgroup analyses, SCORAD scores significantly decreased after probiotic treatment especially in children younger than age 12, with breastfeeding > 6 months, and with mite sensitization ( P < 0.001). Conclusion Supplementation of a probiotic mixture of LP and LF is associated with clinical improvement in children with AD.