Probiotic lactic acid bacteria show enhanced immune-regulatory capacity in combination with prebiotic oligosaccharides

The combination of probiotic bacteria with prebiotics (synbiotics) is considered to selectively manipulate the composition of the microbiota in direction to health benefits of the host. This is of special interest regarding the growing application of synbiotics in prevention and treatment of diseases. Aim of the study was to investigate the impact of different bacterial strains in combination with prebiotic oligosaccharides on cytokine release of human monocyte-derived dendritic cells (MoDC). Immature MoDC prepared from peripheral blood of healthy non-atopic volunteers were stimulated with a Lactobacillus and Bifidobacterium strain in different concentrations in the presence of different combinations of prebiotic GOS (galacto oligosaccharides), FOS (fructose oligosaccharides) and AOS (pectin derived acidic oligosaccharides). IL-12p70 and IL-10 were analyzed after 24 h in cell-free supernatants. Incubation of MoDC with different concentrations of the Lactobacillus and Bifidobacterium strains in combination with prebiotic oligosaccharides revealed that GOS/FOS (9:1) and GOS/FOS/AOS (9:1:2) had a significant additive effect on bacteria-induced IL-10 secretion of human MoDC, while the ability of these prebiotic oligosaccharides to increase IL-12p70 production was less pronounced. Enhanced secretion of IL-10 by bacteria-treated human MoDC induced by GOS/FOS and GOS/FOS/AOS suggests immuno-regulatory capacities in vitro. Thus, the tested Bifidobacterium and Lactobacillus strains in combination with prebiotic oligosaccharides might be considered as health promoting synbiotics providing new strategies for the therapeutic treatment of diseases including immune-regulatory disorders, such as skin diseases, allergy or infection and open new aspects for the application as allergy preventing ingredients in food.