Early markers of allergic disease in a primary prevention study using probiotics: 2.5-year follow-up phase.

BACKGROUND: We previously reported that a Lactobacillus acidophilus probiotic strain (LAFTI) L10/LAVRI-A1) given for the first 6 months of life increased the risk of allergen sensitization at 1 year of age. METHODS: To assess the effects on subsequent allergic outcomes, 153 children from the initial prevention cohort (n = 178) were reviewed at 2.5 years of age. Clinical outcomes were assessed in relation to (i) probiotic supplementation; and (ii) immune function previously assessed at 6 months of age. RESULTS: Supplementation with this probiotic did not reduce the risk of dermatitis at 2.5 years (31/74, 42%) compared with that in placebo group (25/76, 34%). There was no significant reduction in any other allergic disease or allergen sensitization. Inhalant sensitization at 2.5 years (n = 29) was associated with higher proportions of circulating CD4+ CD25+ regulatory T-cell populations (P = 0.005) and higher allergen-induced FOXP3 levels (P = 0.003) at 6 months. This was also seen in children with dermatitis. Children with dermatitis at 2.5 years also had significantly lower toll-like receptor 4 lipopolysaccharide responses at 6 months of age (IL-12 P = 0.04, IL-6 P = 0.039) and lower polyclonal (PHA) responses (IFN-gamma P = 0.005, IL-10 P = 0.001, and IL-6 P = 0.001). Children who had previously received the probiotic had fewer gastrointestinal infections in the preceding 18 months (P = 0.023). CONCLUSION: The LAFTI L10 probiotic strain did not have any significant effect on allergy outcomes. Allergic children showed a number of early differences in immune function including altered regulatory T-cell markers and innate immune function.

Supplementation with Lactobacillus rhamnosus or Bifidobacterium lactis probiotics in pregnancy increases cord blood interferon-gamma and breast milk transforming growth factor-beta and immunoglobin A detection.

BACKGROUND: This study explored the effects of maternal probiotic supplementation on immune markers in cord blood (CB) and breast milk. METHODS: CB plasma and breast milk samples were collected from a cohort of women who had received daily supplements of either 6 x 10(9) CFU/day Lactobacillus rhamnosus HN001 (n=34), 9 x 10(9) CFU/day Bifidobacterium lactis HN019 (n=35) or a placebo (n=36) beginning 2-5 weeks before delivery and continuing for 6 months in lactating women. CB plasma and breast milk (collected at 3-7 days, 3 months and 6 months postpartum) were assayed for cytokines (IL-13, IFN-gamma, IL-6, TNF-alpha, IL-10, TGF-beta1) and sCD14. Breast milk samples were also assayed for total IgA. RESULTS: Neonates of mothers who received a probiotic had higher CB IFN-gamma levels (P=0.026), and a higher proportion had detectable blood IFN-gamma levels, compared with the placebo group (P=0.034), although levels were undetectable in many infants. While this pattern was evident for both probiotics, when examined separately only the L. rhamnosus HN001 group showed statistically significant higher IFN-gamma levels (P=0.030) compared with the placebo group. TGF-beta1 levels were higher in early breast milk (week 1) from the probiotic groups (P=0.028). This was evident for the B. lactis HN019 group (P=0.041) with a parallel trend in the L. rhamnosus HN001 group (P=0.075). Similar patterns were seen for breast milk IgA, which was more readily detected in breast milk from both the B. lactis HN019 (P=0.008) and the L. rhamnosus HN001 group (P=0.011). Neonatal plasma sCD14 levels were lower in the B. lactis HN019 group compared with the placebo group (P=0.041). CONCLUSION: The findings suggest that supplementation with probiotics in pregnancy has the potential to influence fetal immune parameters as well as immunomodulatory factors in breast milk.