Differential Effect of Dietary Fibers in Intestinal Health of Growing Pigs: Outcomes in the Gut Microbiota and Immune-Related Indexes.

Although dietary fibers (DFs) have been shown to improve intestinal health in pigs, it is unclear whether this improvement varies according to the type/source of DF. In the current study, we investigated the impact of dietary supplement (15%) of pea-hull fiber (PF), oat bran (OB), and their mixture (MIX, PF, and OB each accounted for 7.5%) in the growth performance as well as intestinal barrier and immunity-related indexes in growing pigs. Twenty-four cross-bred pigs (32.42 ± 1.95 kg) were divided into four groups: CON (basal diet with no additional DF), PF, OB, and MIX. After 56 days of feeding, we found that the growth performance of PF pigs was decreased ( < 0.05) compared with pigs in other groups. Results of real-time polymerase chain reaction and Western blot showed that the improvement of immune-related indexes (e.g., interleukin 10 []) in OB and MIX pigs mainly presented in the ileum, whereas the improvement of intestinal barrier-related indexes (e.g., and ) mainly presented in the colon. Whether in the ileum or colon, such improvement of immune function may be dependent on NOD rather than TLR-associated pathways. Amplicon sequencing results showed that PF and MIX pigs shared a similar bacterial community, such as lower abundance of ileal Clostridiaceae and colonic than that of CON pigs ( < 0.05). Our results indicate that OB and MIX, rather than PF, benefit the intestinal health in growing pigs, and multiple-sourced DF may reduce the adverse effect of single-soured DF on the growth performance and gut microbiota in pigs.