PURPOSE OF THE STUDY.
Probiotic supplementation has been shown in some studies to decrease the development and incidence of atopic dermatitis and allergic sensitization. This study sought to identify the immunomodulatory effect of prenatal and postnatal Lactobacillus reuteri supplementation.
Sixty-one children from a double-blind, randomized, placebo-controlled probiotic trial with available blood cell samples from at least 3 time-points, including birth and 6, 12, or 24 months. Twenty-nine children received probiotic supplementation from 36 weeks through 12 months of age and 32 received placebo.
Peripheral blood mononuclear cells were isolated from blood samples and challenged with ovalbumin, birch, cat, or phytohaemagglutinin. Interleukin (IL)-5, IL-10, IL-13, interferon-ɣ, CCL17, CCL18, CCL22, and CXCL10 were measured. The effect of probiotics on T helper cell differentiation was indirectly explored.
Probiotic supplementation decreased mean allergen-induced production of several cytokines at several time periods, particularly IL-5 and IL-10. Differences were most significant for cat. Children with IgE-associated disease had predictably higher levels of birch-induced CCL17 at 12 and 24 months of age, as well as higher ovalbumin-induced CXCL10 at birth and CCL17 at age 24 months. Analysis showed that the observed difference in cytokine response in the probiotic treatment group was independent of the development of allergy.
Infants given the probiotic supplement L reuteri have decreased allergen responsiveness and possibly greater capacity for immunoregulation during infancy.
There is growing interest in the use of probiotic supplementation to prevent or modulate atopic disease. The authors had previously shown that prenatal and postnatal probiotic supplementation with L reuteri reduced both allergic sensitization and prevalence of IgE-associated atopic dermatitis at 2 years of age. This study further demonstrated a general reduction in production of both T helper cells 1 and 2 cytokines in the subjects treated with Lactobacillus, prompting the authors to suggest a possible mechanism for their previous findings. A weaknesses of this study is the failure to correlate allergen and mitogen cytokine responses with probiotic treatment and clinical outcomes in this patient group. In addition, the study cannot account for the variation in size or timing of exposures to eggs, birch, or cat that certainly affects the likelihood of sensitization and peripheral mononuclear cell responsiveness. Various effects on the immune system have been demonstrated after probiotic treatment; this study would seem to add support for the immunomodulating effect of Lactobacillus supplementation in pregnancy and early childhood, although more research is needed to elucidate the mechanisms involved.
- Copyright © 2013 by the American Academy of Pediatrics