Impact of Maternal Atopy and Probiotic Supplementation During Pregnancy on Infant Sensitization: a Double-blind Placebo-controlled Study

Background: The effects of breastfeeding and probiotics on infant sensitization still remain discrepant.

Objective: To explore probable explanatory factors in infant sensitization and the protective effect of probiotics.

Methods: Altogether 171 mother-infant pairs from an ongoing placebo-controlled double-blind study with nutrition modulation by dietary counselling and probiotic supplementation were studied. Skin prick testing was done in infants at 6 and 12 months and in mothers at third trimester of pregnancy. The breast milk concentrations of cytokines TGF-beta2, soluble CD14, IFN-gamma, TNF-alpha, IL-10, IL-6, IL-4 and IL-2 were measured.

Results: The risk of sensitization increased in infants with allergic mothers breastfeeding over 6 months [odds ratio (OR=4.83, P=0.005)], or exclusively breastfeeding over 2.5 months (OR=3.4, P=0.018). Probiotic supplementation had a protective effect against sensitization in infants with a high hereditary risk due to maternal sensitization (OR=0.3, P=0.023). The concentration of TGF-beta2 tended to be higher in the colostrum of the mothers in the probiotic group as compared with those on placebo (probiotic/placebo ratio=1.50, P=0.073). A similar result was obtained in the subgroup of allergic mothers (probiotic/placebo ratio=1.56, P=0.094).

Conclusion: Infants of atopic mothers, specifically when breastfed exclusively over 2.5 months or totally over 6 months, had a higher risk of sensitization at the age of 12 months. This risk could be reduced by the use of probiotics during pregnancy and lactation, partly by resulting in a beneficial composition of the breast milk.