PC3022: The Effectiveness of the Probiotic L.rhamnosus GG in Pediatric Atopic Dermatitis: Results from the Propad Trial

Background: Atopic dermatitis (AD) is a chronic inflammatory skin disease affecting up to 20% of children in Western countries associated with aberrant skin barrier function and alteration of skin and gut microbiome. The ProPAD study aimed to investigate the therapeutic efficacy of the probiotic L.rhamnosus GG (LGG) in children with AD.

Methods: The study design was approved by the Ethics Committee of our Institution (Protocol n.184/19). The trial was registered on ClinicalTrials.gov (NCT03863418). A total of 100 AD children aged 6-36 months were randomized in a double-blind placebo-controlled trial to receive placebo (Group A) or LGG 1x1010 CFU daily (Group B) for 12 weeks. The primary outcome was the evaluation of the therapeutic efficacy of LGG supplementation on AD severity comparing SCORAD index at baseline (T0) and at 12 weeks (T12). A mean improvement of 8.7 points on the SCORAD index was considered as clinically important difference (MCID). The secondary outcomes were the evaluation of SCORAD index at 4-week after the end of the LGG treatment (T16); number of days without rescue medications; changes in Infant Dermatitis Quality of Life Questionnaire (IDQOL); specific serum IgE level to food and environmental allergens; gut microbiome structure and function (short chain fatty acids production); skin microbiome structure; occurrence of common infectious diseases

Results: At T0 the median SCORAD index was similar into the two groups. From T0 to T12 a reduction of SCORAD index was observed in both groups, with a significantly higher reduction in GroupB(p < 0.001). The rate of subjects achieving the minimum clinically important MCID of 8.7 units for SCORAD index after 12 weeks of treatment was significantly higher in group B (p < 0.05). The effect remained stable in group B also 4 weeks after the end of LGG treatment. The number of days without rescue medications was significantly higher in Group B. IDQOL score, improved from T0 to T12 in the Group B (p < 0.05). A beneficial modulation of skin and gut microbiome was observed only in patients enrolled in the Group B. Specific serum IgE and the occurrence of infections resulted similar in the two study groups.

Conclusion: These data support the potential of the probiotic LGG approach as adjunctive strategy in pediatric AD. The beneficial effects on disease severity and quality of life paralleled with a beneficial modulation on microbiome.