Synbiotic Effects of Enzyme and Probiotics on Intestinal Health and Growth of Newly Weaned Pigs Challenged With Enterotoxigenic F18+ Escherichia coli

Abstract

This study aimed to investigate the effect of dietary supplementation with xylanase and probiotics on growth performance and intestinal health of nursery pigs challenged with enterotoxigenic Escherichia coli (ETEC). Sixty-four newly weaned pigs (32 barrows and 32 gilts with 7.9 ± 0.4 kg BW) were allotted in a randomized complete block design (2 × 2 factorial). Two factors were ETEC challenge (oral inoculation of saline solution or E. coli F18⁺ at 6 × 10⁹ CFU) and synbiotics (none or a combination of xylanase 10,000 XU/kg and Bacillus sp. 2 × 10⁸ CFU/kg). All pigs were fed experimental diets following NRC (2012) in two phases (P1 for 10 d and P2 for 11 d). The ETEC was orally inoculated on d 7 after weaning. Feed intake and BW were measured on d 7, 10, 15, and 20. On d 20, pigs were euthanized to collect samples to measure gut health parameters and microbiome. Synbiotics increased (P < 0.05) ADG in phase 1 and ETEC reduced (P < 0.05) ADG and G:F in the post-challenge period. ETEC increased (P < 0.05) the fecal score of pigs from d 7 to 13; however, synbiotics reduced (P < 0.05) it at d 9 and 11 in challenged pigs. ETEC increased (P < 0.05) mucosal MDA, IL-6, Ki-67⁺, and crypt depth, whereas synbiotics tended to reduce TNFα (P = 0.093), protein carbonyl (P = 0.065), and IL-6 (P = 0.064); reduced (P < 0.05) crypt depth and Ki-67⁺; and increased (P < 0.05) villus height. ETEC reduced (P < 0.05) the relative abundance of Bacteroidetes and Firmicutes and increased (P < 0.05) the relative abundance of Proteobacteria. In conclusion, ETEC challenge reduced growth performance by affecting microbiome, immune response, and oxidative stress in the jejunum. Synbiotics enhanced growth performance by reducing diarrhea, immune response, and oxidative stress in the jejunum.

Keywords: Escherichia coli; growth performance; intestinal health; newly weaned pigs; probiotics; synbiotics; xylanase.

Figure 1

Fecal score of pigs challenged with ETEC (CH) on d 7 post-weaning and fed diets supplemented with a synbiotic (SY). * d 7 pm: CH: (P < 0.001), SY: (P = 0.685), CH × SY: (0.892); d 9: CH: (P < 0.001), SY: (P = 0.124), CH × SY: (P < 0.05); d 11: CH: (P < 0.001), SY: (P = 0.236), CH × SY: (P < 0.05); d 13: CH: (P < 0.05), SY: (P = 0.718), CH × SY: (P = 0.471). ^a,b Within a column, means without a common superscript letter differ (P < 0.05).

Figure 2

Relative abundance of jejunal mucosa-associated microbiota at the phylum level in pigs challenged with ETEC (CH) on d 7 post-weaning and fed diets supplemented with a synbiotic (SY). Each pattern represents a particular bacterial phylum. Phylum sequences that did not achieve 0.5% within each phylum were combined as “Others.” 1: ETEC challenge (CH); 2: Synbiotic (SY). Proteobacteria: CH: (P < 0.05), SY: (P = 0.339), CH × SY: (P = 0.668). Bacteroidetes: CH: (P < 0.05), SY: (P = 0.162), CH × SY: (P = 0.542); Firmicutes: CH: (P < 0.05), SY: (P = 0.523), CH × SY: (P = 0.803).

Figure 3

Alpha diversity of jejunal mucosa-associated microbiota at the family level estimated with Chao1 richness (A), Shannon diversity (B), and Simpson diversity (C) in pigs challenged (CH) with ETEC on d 7 post-weaned and fed diets supplemented with a synbiotic (SY). 1: ETEC challenge; 2: Synbiotic; SY: synbiotic; CH: challenge; CH × SY: Challenge and synbiotic.

Figure 4

Alpha diversity of jejunal mucosa-associated microbiota at the genus level estimated with Chao1 richness (A), Shannon diversity (B), and Simpson diversity (C) in pigs challenged (CH) with ETEC on d 7 post-weaned and fed diets supplemented with a synbiotic (SY). 1: ETEC challenge; 2: Synbiotic; SY: synbiotic; CH: challenge; CH × SY: Challenge and synbiotics.