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 × 109 CFU/day Lactobacillus rhamnosus HN001 (n=34), 9 × 109 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-γ, IL-6, TNF-α, IL-10, TGF-β1) and sCD14. Breast milk samples were also assayed for total IgA.
Results Neonates of mothers who received a probiotic had higher CB IFN-γ levels (P=0.026), and a higher proportion had detectable blood IFN-γ 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-γ levels (P=0.030) compared with the placebo group. TGF-β1 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.