A comparative study of the effects of crude chicory and inulin on gut health in weaning piglets

Abstract

Dysfunction of the host-microbial balance and an impaired intestinal barrier can trigger inflammation and increase the antigen penetration. Inulin, commonly extracted from chicory root, is a prebiotic beneficial to gut health. The objective of this study was to compare the effect of chicory flour to inulin on gut health, few weeks after weaning. Two dose-dependent experiments (E1 and E2) were performed sequentially, each consisting of 80 castrated male piglets, weaned at day 21 and subsequently divided in 3 groups with ad libitum feed: control (Ctrl), inulin (INU) and crude chicory flour (CHI). For INU and CHI groups, a daily supplementation with the equated ‘inulin content’ increasing weekly was done by oral force-feeding, while the Ctrl groups received an isotonic sucrose solution. For E1, these doses were 1.5 g/day, 2 g/day and 2.5 g/day in W1, W2 and W3, respectively. For E2, these doses were 3 g/day, 4 g/day and 5 g/day in W1, W2 and W3, respectively. For each experiment at W0, W1 and W3, eight piglets per group were euthanized to assess gut structural and functional parameters. In E1, the CHI had lower average daily calorie intake (kcal/day) only at W3, while in E2 it was consistently lower than Ctrl and INU. In W3 of E2, CHI showed improved villi-to-crypt ratio and lower diarrhea occurrence than INU and Ctrl. Both supplemented groups in E2 showed higher butyrate production and lower D-xylose permeability (W3), compared to Ctrl. Interestingly, in E2, CHI had a more dominant effect on increasing the abundance of health promoting genera like Catenisphaera, Butyricicoccus, etc. and decreasing harmful genera like Erysipelotrichaceae_UCG-002 and Turicibacter. In E2, on W3 several inflammatory target genes (CXCL10, IL18, TNFα) and inflammation signalling genes (MyD88, NFκB1) were downregulated in ileum of INU and CHI. In colon, both chicory and inulin, proved to be beneficial, as the inflammation signalling and inflammatory targets genes NFκB1, DEFβ4A, TLR2 and IFNα were significantly downregulated. Therefore, crude chicory flour might also be a promising cost-effective alternative supplement to improve gut health in weaned piglets.