Efficacy of probiotic Lactobacillus GG on allergic sensitization and asthma in infants at risk.

BACKGROUND Probiotics are perceived to exert beneficial effects in the prevention and treatment of allergic diseases. OBJECTIVE There are conflicting data from studies as to an impact on allergic sensitization and asthma. METHODS Our prospective double-blind study randomly assigned 131 children (6-24 months old) with at least two wheezing episodes and a first-degree family history of atopic disease to 6 months of Lactobacillus rhamnosus (LGG, 10(10) colony forming units) or placebo. Atopic dermatitis and asthma-related events (e.g. need of inhalation, symptom-free days) were documented throughout the intervention and 6-month follow-up. We determined IgE, a representative panel of specific IgE, eosinophils, eosinophilic cationic protein, and TGF-beta before, at the end of intervention, and after 6 months of follow-up. RESULTS There were no significant differences as to atopic dermatitis or asthma-related events. In a subgroup with antecedent allergic sensitizations, asthmatic complaints were even slightly worse. We found fewer sensitizations towards aeroallergens after 6 months of LGG (P=0.027) and after 6 months of follow-up (P=0.03). Supplementation was well-tolerated and no severe adverse events occurred. CONCLUSIONS In young children with recurrent wheeze and an atopic family history, oral LGG had no clinical effect on atopic dermatitis or asthma-related events, and only mild effects on allergic sensitization. This effect persisted 6 months after the cessation of the supplementation.