Background and Aims Transmission of immune competence from mothers to newborns is crucial for optimal development of neonate immune system. Maternal perinatal probiotics supplementation having been observed to be able to modulate this process, the goal of the present study was to investigate the importance of the time window of probiotics intervention (pregnancy/lactation) on early-life immune maturation and response to immunization.
Methods Pregnant C57/BL6 mice were supplemented with Bifidobacterium lactis CNCM I-3446, 2.5x108 CFU/day, during either end of gestation and lactation, end of gestation only or lactation only. Maltodextrin was given during both periods (placebo) or in replacement of probiotics when not administered. Immune maturation was assessed by measuring natural mucosal IgA production (ELISPOTs) at weaning and 6 weeks later. Pups were mucosally immunized at weaning, and again four weeks later, with live attenuated Salmonella typhimurium ΔaroA. Two weeks after the second immunization, specific antibody responses in serum were analyzed.
Results All probiotic regimens significantly enhanced natural IgA production in pups in comparison to placebo, an effect observable up to the end of study, 6 weeks post-weaning. Supplementation during end of pregnancy and lactation, or lactation only provided significantly highest values. Specific antibody titers tended to be potentiated by all three regimens in pups responding to immunization, with highest values being obtained after supplementation during both periods.
Conclusions This study further supports the benefit of maternal perinatal intervention with probiotics on neonatal immune maturation, moreover emphasizing that supplementation during both pregnancy and lactation is needed to achieve overall optimal effects.