Specific prebiotic oligosaccharides modulate the early phase of a murine vaccination response.

The immune-modulatory effect of specific prebiotic oligosaccharides was shown in previous preclinical and clinical studies. To enhance the understanding of this effect, kinetic aspects of immune modulation and the correlation between microbiological and immunological parameters were investigated in a murine vaccination model. C57BL/6 mice were supplemented with short-chain galactooligosaccharides and long-chain fructooligosaccharides (ratio 9:1; Immunofortis()) in combination with pectin-derived acidic oligosaccharides. The timing of supplementation was varied around the primary (day 0) and secondary (day 21) vaccinations. Supplementation before the primary vaccination was necessary to increase delayed-type hypersensitivity responses (DTH) significantly at day 30. Supplementation after day 8 did not affect the DTH response at day 30, indicating that immune modulation occurred during the early phase. Therefore, correlation analysis of microbiological and immunological parameters was performed in a shortened experiment to focus on the early phase. At day 9 post-priming, the percentages of cecal lactobacilli were correlated to the DTH responses (p=0.01). Furthermore, the results suggested that yet unidentified factors may play a role. Additional analysis of intestinal Peyer's patch major lymphocyte populations did not show effects of supplementation. In conclusion, a specific oligosaccharide mixture was shown to exert its immune-modulatory effect during the early phase of a murine immune response. The results are consistent with a role of the microbiota and possibly other factors in oligosaccharide-induced immune modulation. Furthermore, the results demonstrate that it is critical to consider kinetic aspects of immune-modulatory and prebiotic effects in order to study their interaction in a meaningful way.