Perinatal Probiotic Mixture and Development of Allergic Sensitization up to 13 Years of Age

<b><i>Background:</i></b> Probiotics have shown promising results in primary prevention of allergies in early years, but the long-term effects on allergic sensitization need more evaluation. <b><i>Objectives:</i></b> We conducted a randomized double-blind placebo-controlled study to determine whether the use of a mixture of pre- and probiotics perinatally affects the prevalence of immunoglobulin E (IgE) sensitization up to 13 years in high-risk children. <b><i>Methods:</i></b> One thousand two hundred twenty-three pregnant women were randomized to receiving probiotics or placebo from 36 gestational weeks until delivery, and their infants received pre- and probiotics or placebo from birth until 6 months. At 2, 5, and 13 years, blood samples were taken to determine specific IgE levels against common foods, pollen, and animal antigens. <b><i>Results:</i></b> The prevalence of IgE sensitization to any allergen was high and increased with age. No significant difference in the prevalence of IgE sensitization to any particular one of the tested allergens was found between the groups. At 2, 5, and 13 years these prevalence rates of IgE sensitization to any allergen were 31.1 and 34.1%, 50.1 and 45.6%, and 61.4 and 56.8% in the probiotic and placebo groups, respectively. At 13 years, IgE sensitization to cat/dog dander was more frequent in the probiotic group compared to the placebo group (40.2 vs. 31.0%, <i>p</i> = 0.03). <b><i>Conclusions:</i></b> In high-risk children, perinatal use of a mixture of probiotics did not affect the prevalence of sensitization to any one of the tested allergens, but it was associated with more frequent IgE sensitization to cat/dog dander at 13 years.