Impact of yeast-derived ß-glucans on the porcine gut microbiota and immune system in early life

Piglets are susceptible to infections in early life and around weaning due to rapid environmental and dietary changes. A compelling target to improve pig health in early life is diet, as it constitutes a pivotal determinant of gut microbial colonization, and maturation of the host's immune system. In this study, we investigated how supplementation of yeast-derived ß-glucans affects the gut microbiota and immune function pre- and post-weaning, and how these complex systems develop over time. From day two after birth until two weeks after weaning, piglets orally received yeast-derived ß-glucans or a control treatment and were then vaccinated against Salmonella Typhimurium. Faeces, digesta, blood and tissue samples were collected to study gut microbiota composition and immune function. Overall, yeast-derived ß-glucans did not improve the vaccination response and only modest effects on faecal microbiota composition and immune parameters were observed, primarily before weaning. As expected, significant differences between the pre- and post-weaning phase were observed in all tested parameters. This study demonstrates that the pre-weaning period offers a 'window of opportunity' for priming of the gut microbiota and immune system through diet. However, the observed changes were modest, and any long-lasting effects of yeast-derived ß-glucans remain to be elucidated.