PURPOSE OF THE STUDY.
The goal of this study was to determine if supplementation with the probiotic Lactobacillus reuteri during the perinatal period and infancy, which had reduced the incidence of allergic sensitization and allergic eczema at age 2 years, reduces the incidence of asthma and allergic rhinoconjunctivitis in school-aged children.
The study population included 184 of 232 Swedish children who had participated in a double-blind, placebo-controlled, randomized controlled trial (RCT) of probiotic supplementation perinatally and during infancy. To be eligible for the RCT, children had to have a family history of allergic disease.
Families were contacted when the children were 7 years old, and the follow-up visit included administration of questionnaires, physical examination, spirometry, measurement of fractional exhaled nitric oxide, and assessment of eczema. Skin prick testing and IgE testing were also performed by using a panel of common food and environmental allergens. The outcome of allergic disease was defined as symptomatic asthma, allergic rhinoconjunctivitis, allergic urticaria, or eczema in the previous year. The prevalence of outcomes between the probiotic and placebo groups was compared.
There were no differences in any of the allergic disease outcomes between the probiotic and placebo groups. Both groups had a similar prevalence of allergic disease generally and asthma, allergic rhinoconjunctivitis, and eczema specifically. The prevalence of allergic sensitization, according to results of both skin prick testing and IgE testing, was also similar between the 2 groups, as were lung function and fractional exhaled nitric oxide levels. Post-hoc analyses to determine if any subpopulation exhibited evidence of benefit found that neither maternal allergic history nor delivery mode was associated with a beneficial effect of probiotic supplementation. Because adherence was high (>95%) in the parent RCT, these findings were not attributable to poor adherence. Probiotic supplementation was also not associated with adverse effects at school age, including effects on growth and gastrointestinal symptoms.
Supplementation with L reuteri perinatally and in infancy transiently reduced the risk of allergic sensitization, but it had no effect on allergic disease outcomes or allergic sensitization at school age.
This long-term follow-up of one of the only “successful” probiotic trials for prevention of allergic disease indicates that any effect of probiotics is, at best, transient. However, recent studies point to a role of the gut microbiome in immune development; it is therefore possible that other approaches to modifying the gut microbiome may prove effective in the prevention of allergic disease.
- Copyright © 2014 by the American Academy of Pediatrics