Effect of Early Postnatal Supplementation of Newborns by Probiotic Strain E. coli O83:K24:H31 on Allergy Incidence, Dendritic cells and Microbiota Targeted loci

Probiotic administration seems to be a rational approach to promote maturation of the neonatal immune system. Mutual interaction of microbiota with host immune system is critical for the setting of appropriate immune responses including tolerogenic one and maintenance of the homeostasis. On the other hand, our knowledge of the modes of actions of probiotics is still scarce. In our study, probiotic strain Escherichia coli O83:K24:H31 (EcO83) was administered to neonates of allergic mothers (AM, neonates with increased risk for allergy development) within 48 hrs after the delivery and the impact of this early postnatal supplementation on allergy incidence and selected immune markers has been analyzed 10 years after the primary EcO83 administration. We have observed decreased allergy incidence in ten-year-old children supplemented by EcO83 (13 of 52 children were allergic) in comparison with non-supplemented children of AM (16 of 42 children were allergic). Dendritic cells (DC) in peripheral blood of EcO83 supplemented children have lower cell surface presence of CD83. Immunomodulatory capacity of EcO83 on dendritic cells was tested in vitro as well. Both myeloid and plasmacytoid DC derived from cord blood progenitor cells increased CD83 expression together with IL-10 secretion after EcO83 stimulation. The effect of early postnatal EcO83 supplementation on gut microbiota composition of ten year old children has been characterized by next generation sequenation and we have not observed significant changes in microbiota composition of EcO83 supplemented and non-supplemented children at the age of ten years. Early postnatal EcO83 supplementation lowered allergy incidence in children of AM. It seems that the beneficial effect of EcO83 is mediated via modulation of DC functional capacities without impacting microbiota composition.