Co-fermented defatted rice bran alters gut microbiota and improves growth performance, antioxidant capacity, immune status and intestinal permeability of finishing pigs

Based on preparation of co-fermented defatted rice bran (DFRB) using Bacillus subtilis, Saccharomyces cerevisiae, Lactobacillus plantarum and phytase, the present study aimed to evaluate the effects of co -fermented DFRB on growth performance, antioxidant capacity, immune status, gut microbiota and permeability in finishing pigs. Ninety finishing pigs (85.30 +/- 0.97 kg) were randomly assigned to 3 treatments (3 replicates/treatment) with a basal diet (Ctrl), a basal diet supplemented with 10% unfer-mented DFRB (UFR), and a basal diet supplemented with 10% fermented DFRB (FR) for 30 d. Results revealed that the diet supplemented with FR notably (P < 0.05) improved the average daily gain (ADG), gain to feed ratio (G:F) and the digestibility of crude protein, amino acids and dietary fiber of finishing pigs compared with UFR. Additionally, FR supplementation significantly (P < 0.05) increased total antioxidant capacity, the activities of superoxide dismutase and catalase, and decreased the content of malonaldehyde in serum. Furthermore, FR remarkably (P < 0.05) increased serum levels of IgG, anti-inflammatory cytokines (IL-22 and IL-23) and reduced pro-inflammatory cytokines (TNF-a, IL-1b and INF -g). The decrease of serum diamine oxidase activity and serum D-lactate content in the FR group (P < 0.05) suggested an improvement in intestinal permeability. Supplementation of FR also elevated the content of acetate and butyrate in feces (P < 0.05). Moreover, FR enhanced gut microbial richness and the abundance of fiber-degrading bacteria such as Clostridium butyricum and Lactobacillus amylovorus. Cor-relation analyses indicated dietary fiber in FR was associated with improvements in immune status, intestinal permeability and the level of butyrate-producing microbe C. butyricum, which was also verified by the in vitro fermentation analysis. These findings provided an experimental and theoretical basis for the application of fermented DFRB in finishing pigs.(c) 2022 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study evaluated the effects of co-fermented defatted rice bran (DFRB) on the growth performance, antioxidant capacity, immune status, gut microbiota, and permeability in finishing pigs. The results showed that co-fermented DFRB significantly improved the growth performance, antioxidant capacity, immune status, gut microbiota, and permeability in finishing pigs. The findings suggest that co-fermented DFRB has potential as a dietary supplement for improving the health and productivity of finishing pigs.