Long-term safety and efficacy of perinatal probiotic intervention: Evidence from a follow-up study of four randomized, double-blind, placebo-controlled trials.

Background: Societies worldwide are faced with a progressive increase in immune-mediated health problems such as allergic, autoimmune, and inflammatory diseases, as well as obesity. Perinatal administration of specific probiotic bacteria is an attractive approach in reducing the risk of these conditions, but long-term efficacy and safety data are lacking. The aim here was to evaluate the clinical benefit and long-term safety of specific probiotics administered during the perinatal period.

Methods: The probiotic strains used were Lactobacillus rhamnosus GG, Bifidobacterium lactis Bb-12, Lactobacillus paracasei ST11, and Bifidobacterium longum BL999. The children involved have subsequently undergone prospective long-term follow-up. In addition to physical examination, data were collected by structured questionnaires on non-communicable diseases and continued probiotic use, and growth data from welfare clinics and school nurses.

Results: Altogether 303 mother-infant pairs were included in the analysis. Seventy-six of 163 (47%) children receiving perinatal probiotics had developed allergic disease compared with 79 of 140 (56%) receiving placebo (OR 0.67, 95% confidence intervals [CI] 0.43-1.06, p = 0.09). Fifty-nine of 133 (44%) children receiving L. rhamnosus GG perinatally had developed allergic disease, OR 0.62, 95% CI 0.38-0.99, p = 0.047, as compared to placebo. We found no differences in growth or non-communicable disease prevalence between children receiving perinatally probiotics or placebo.

Conclusions: Perinatal probiotic administration is safe in long-term follow-up. Children receiving L. rhamnosus GG perinatally tended to have decreased allergy prevalence.