Immunomodulatory effects of E.coli Nissle 1917 and β-glucans in early life

Background: Infectious diseases are problematic for the pig sector worldwide, with the weaning period being the most critical period in a pig’s life. A promising strategy to reduce the incidence of infectious diseases is immunomodulation by feed in early life. Therefore, the immunomodulatory effects of two feed additives, yeast-derived β-glucans and E.coli Nissle 1917 (EcN), were studied in vitro and in vivo. Materials and methods: In vitro cultured dendritic cells (DCs) were used to assess the immunomodulatory effects of both feed additives. Read-out parameters included upregulation of maturation markers and production of cytokines after co-cultivation with the feed additives. For the in vivo assessment, both feed additives were administered to neonatal piglets and immune parameters (e.g. DC maturation and ex-vivo re-stimulation responses) were assessed in blood- and tissue sam-ples collected at pre- and post-weaning time points. Results: Yeast-derived β-glucans and EcN induced differential DC responses in vitro, with respect to upregulation of DC maturation markers (e.g. CD80/86) and production of cytokines (e.g. TNFα and IL-10). In line with these in vitro results, EcN promoted DC maturation during the pre-weaning phase of the in vivo study. Furthermore, ex-vivo re-stimulated immune cells from EcN treated animals produced higher amounts of the anti-inflammatory cytokine IL-10. Conclusion: These results indicate that yeast derived β-glucans and EcN demonstrated to possess immunomodulatory properties, but the type and magnitude differed. Especially EcN has the potential to enhance the porcine immune system during the pre-weaning phase, but any long lasting effects of the remain to be elucidated.