The host-microbiota interactome in early life and its role in gut immune development

In order to develop more sustainable livestock production systems, the health status of production animals has to be improved. Pre- and probiotics are interesting candidates to enhance health by means of stimulating growth of beneficial gut bacteria and by improving the intestinal barrier. Successful application of such dietary components can result in reduction of antibiotic usage, which will lower the pressure on the emergence of antibiotic resistant microbes. In this project, the emphasis is given on steering the microbiota composition in early life, since this will likely have the largest effect on immunity and gut health of the host animal. We designed and carried out a 10-week study during which dietary interventions (viable EcN cells, and beta-glucans) were perorally administered to pigs from day 2 to day 44. Blood, tissue, mucosal scrapings, luminal content and faecal samples were collected at different pre- and post-weaning time points to study the pre- and post-weaning effects of the dietary interventions on gut microbiota composition, gene expression of the gut epithelium, and the immune system. Additionally, we investigated whether the dietary interventions modulate the pig’s immunocompetence (i.e. the ability to produce an effective immune response to an antigen, thereby providing protection in case of exposure to a pathogen) by analysing the antibody responses induced after oral vaccination against Salmonella enterica serovar Typhimurium.