D1.433 - The effect of preventive administration of probiotic strain E. coli 083:H24:K31 on selected immune characteristics of eight-year-old children

Although the beneficial effects of probiotics are well established, their mechanisms of action remain poorly understood. Epidemiological studies indicate that early-life probiotic administration may reduce allergy development. This study evaluates the long-term immunological effects of E. coli 083:H24:K31 administration in neonates at high risk of allergy. 

Children of allergic mothers, predisposed to allergy, were enrolled in a randomized trial and given E. coli 083:H24:K31 in early infancy. At eight years of age, immune parameters were analyzed. Peripheral blood samples were collected, and cytokine levels (IFN-γ, IL-4, IL-5, IL-13, IL-10, TGF-β) were measured using ELISA. The proportion and functional characteristics of regulatory T cells (Tregs) were assessed by flow cytometry. 

The concentration of Th1 cytokine IFN-γ was significantly lower in allergic children compared to healthy controls, while Th2 cytokines IL-4 and IL-13 were elevated. Regulatory cytokines (IL-10, TGF-β) were lower in allergic children. Unexpectedly, the proportion of Tregs in allergic children was higher than in healthy controls, but their suppressive function was impaired. Probiotic administration was associated with normalization of cytokine levels and improved Treg function, reducing the disparity between allergic and non-allergic children.

Early administration of E. coli 083:H24:K31 in infancy was associated with modulation of immune responses at eight years of age. Probiotic supplementation reduced Th2 cytokine levels, enhanced regulatory cytokine production, and improved Treg functionality in allergic children. These findings suggest that probiotic administration may help restore immune balance in children predisposed to allergy, potentially reducing long-term allergy risk.