Oral administration of E.coli Nissle 1917 – Effects on the porcine gut microbiota, intestinal epithelium and the immune system in early life. Porcine in vivo study - intervention with E Coli Nissle 1917

Early in life and particularly around weaning, piglets are susceptible to infections because of prompt social, environmental and dietary changes. Probiotic bacteria have gained increasing popularity as dietary interventions because of the heightened awareness of the direct link between (digestive) health and diet. In the present study, faeces, digesta, mucosal scrapings, blood, and mesenteric lymph nodes were collected to investigate the effect of E.coli Nissle 1917 (EcN) on the gut microbiota composition, intestinal epithelial gene expression and immune system over time. From day two after birth until two weeks post-weaning, piglets perorally received EcN or a control treatment, followed by an oral vaccination against Salmonella enterica serovar Typhimurium to assess the immune competence. EcN showed to reduce the diversity of taxa within the phylum of Proteobacteria, induce an apparent antagonistic effect against Treponema and proliferation of T-cells, activate NK cells and enhance IL-10 production in ex vivo stimulated MLN cells. These outcomes were primarily observed pre-weaning, and point towards favorable effects on the gut microbiota and a more tolerant or anti-inflammatory immune response. No significant effects between the treatment groups were observed for body weight, epithelial gene expression, and the immune competence was not enhanced upon vaccination. Any effects observed during the post-weaning period were modest. Overall, this study demonstrates that the pre-weaning period offers a ‘window of opportunity’ to modulate the gut microbiota and immune system by dietary interventions such as EcN.