 Methods. To study this hypothesis, a randomised, double-blind placebo-controlled trial will be carried out by administration of probiotics to pregnant women with previous or recent atopic disease as well as to their offspring. Primary outcome parameters are firstly the prevalence and severity of sensitization and atopic disease in the offspring during a follow-up of two years. Secondary outcome parameters are the change in stool composition during treatment with probiotics and in-vitro production of cytokines by PBMCs collected at 3 months, 1 year and 2 years of age. 