RCT 3 Randomized double-blind, placebo-controlled clinical trial of 3 groups. Pregnant women (n=241) with a history of atopic diseases have been assigned to one of the treatment groups: to receive for 2 months before delivery and for 2 months thereafter, when they are breast-feeding, either placebo or Lactobacillus rhamnosus and Bifidobacterium longum or Lactobacillus paracasei and Bifidobacterium longum.