Effects of soluble and insoluble dietary fiber supplementation on growth performance, nutrient digestibility, intestinal microbe and barrier function in weaning piglet

Abstract

Our objectives were to evaluate the effects of dietary soluble fiber (inulin) and insoluble fiber (lignocellulose) supplementation on growth performance, nutrient digestibility, serum biochemical profile, hindgut microbe and barrier function of weaning piglets. Thirty 24 ± 1-d-old piglets (BW 7.50 ± 0.31kg) were randomly allotted to five treatments, and fed basal diet (control), 1% insoluble dietary fiber diet (IDF), 1% soluble dietary fiber diet (SDF), 0.75% insoluble fiber + 0.25% soluble fiber diet during the first two weeks and 0.25% insoluble fiber + 0.75% soluble fiber diet during the last two weeks (CRMDF), and 0.5% insoluble fiber + 0.5% soluble dietary fiber diet (MDF). The trial lasted for 4 weeks. Compared with control group, diet MDF and IDF decreased the ratio of feed to gain (F/G) (P < 0.05) in the first two weeks, diet CRMDF and MDF decreased F/G in the whole period (P < 0.05). Meanwhile, MDF-fed piglets had a lower diarrhea incidence (P < 0.05) than that of control in the last two weeks. Diet CRMDF and MDF increased serum total protein (TP) and albumin (ALB) concentrations (P < 0.05) in the piglets. All fiber groups showed a higher (P < 0.05) apparent total tract digestibility (ATTD) for dry matter (DM), crude protein (CP) and organic matter (OM) than control group. Diet IDF up-regulated the mRNA level of sodium-glucose cotransporter 1 (SGLT1) in jejunum (P < 0.05). Additionally, diets CRMDF and MDF up-regulated barrier function-related genes (OCLN, CLDN-1, Muc1, IL-10) mRNA levels in the ileal (P < 0.05). Diets IDF and MDF also increased Lactobacillus amounts in the ileal digesta (P < 0.05). Moreover, piglets fed IDF, CRMDF and MDF diets had higher (P < 0.05) concentrations of short-chain fatty acids (SCFAs) in caecal digesta than those in control group. In conclusion, insoluble fiber might be more preferable than soluble fiber to promote the nutrients digestibility in the first two weeks post-weaning piglets. Furthermore, diets supplemented with both soluble fiber and insoluble fiber were more effective than supplementation alone to improve blood biochemical indices, nutrients digestibility, hindgut microbe and gut barrier function.