Neonatal and maternal dietary interventions driving microbiota and functionality in piglet gut compartments.

Feed additives aiming to improve gastrointestinal health are frequently supplied to piglets after weaning (d28) but might be more effective when administered before weaning. In this period, feed additives can either be administered directly to neonates, or indirectly via sow's feed. It is yet unknown what the effect of the administration route is on gut functionality and health in the piglets. Therefore, we compared the effect of different dietary interventions on gut functionality after maternal administration (lactation feed) to the neonatal administration route (oral gavage). These feed interventions included medium chain fatty acids (MCFA), beta-glucans (BG), and galacto-oligosaccharides (GOS). For the maternal administration route, MCFA showed a significant difference in alpha diversity parameter, observed species at d1 and one differentially expressed gene (DEG), and 99 DEG at d31. Pathway enrichment analysis showed association to immune processes and metabolism. For BG, only 21 DEG were observed at d31, these DEGs were associated to signal transduction and sympathetic nerve pathway. For GOS, 816 DEG were observed for GOS at d1, and 77 at d31, where DEGs at d1 were associated to immune processes. For the neonatal administration route, MCFA showed 94 DEG and GOS 6 DEG. Where DEGs in MCFA were mainly associated to cell adhesion processes. When comparing the administration routes directly between treatment groups, we observed significant differences in alpha diversity parameters, observed species at d31 for MCFA, Shannon for GOS, as well as for beta diversity in GOS. For MCFA 515 DEG were observed, for BG 503 DEG, and for GOS 996 DEG. Where for MCFA most pathways were associated to immunological processes, BG showed more metabolism, and GOS mainly metabolism with a few immunological processes. The type of intervention and the administration route influence gut functionality of the piglets. MCFA administration led to a more differentially orchestrated response when comparing the neonatal and maternal administration route then the other two additives. This implies that for each nutritional intervention in early life of a pig the optimal route of administration needs to be determined.