Probiotics and atopic eczema: a double-blind randomised controlled trial

Aims Atopic disorders are common in young children. The development of atopy may be influenced by exposure to microbes in early life. We tested the hypothesis that administration of a multi-strain probiotic during pregnancy and to young infants would prevent atopy in childhood. Methods Pregnant women from 36 weeks gestation and their infants to age 6 months took daily either a probiotic consisting of two strains of lactobacilli and two strains of bifidobacteria or a matching placebo. Most infants had a first degree relative with atopy. The primary outcome was diagnosed eczema at age 2 years. Secondary outcomes were skin prick responses (SPRs) to common allergens and immune responses measured at birth and age 6 months. Results 220 infants were randomised to the probiotic and 234 to the placebo group. A similar proportion of infants in the probiotic and placebo group developed eczema (34.1% and 32.4% respectively; p=0.71). A SPR to one or more common allergens occurred in 18/171 (10.5%) infants in the probiotic and 32/173 (18.5%) in the placebo group (OR 0.52, 95% CI 0.28-0.98). The main difference between the groups was in early sensitisation to cow's milk and hen's egg proteins. Atopic eczema (eczema and a positive SPR) occurred in 9/171 (5.3%) children in the probiotic and 21/173 (12.1%) in the placebo group (OR 0.40, 95% CI 0.18-0.91). Cord blood eosinophil count was reduced (p=0.024) and stimulated IL-12p70 concentrations in venous blood at age 6 months elevated (p = 0.022) in the probiotic compared with the control group. Conclusions The probiotic reduced the frequency of atopic eczema and atopic sensitisation and promoted a Th1 orientation of the immune system. Probiotics administered during pregnancy and early infancy may be effective in the prevention of atopy.