131 Effects of Bacillus spp. probiotics on systemic immunity and intestinal health of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli

摘要

The experiment was conducted to investigate the effects of Bacillus spp. on systemic immunity and intestinal health of weaned pigs infected with F18 E. coli. Weaned pigs (n = 36, 7.61 ± 0.40 kg BW) were randomly allotted to one of three treatments: a control diet and two diets supplemented with 500 mg/kg of Bacillus spp. strain 1 (PRO1) or strain 2 (PRO2). The experiment was conducted for 28 d, including 7 d before and 21 d after the first E. coli inoculation (d 0). The doses of F18 E. coli inoculum were 1010 cfu/3 mL oral dose daily for 3 consecutive days. Serum samples were collected on d 0 before inoculation, and d 3, 7, 14, and 21 post-inoculation (PI) to measure inflammatory meditators. All pigs were euthanized on d 21 PI to collect tissue samples for gut morphology, bacterial translocation, and gene expression analysis. Data were analyzed using the Mixed Procedure of SAS. Pigs in PRO1 had reduced (P < 0.05) serum haptoglobin on d 3 and d 6 PI compared with pigs in control. Supplementation of PRO1 or PRO2 reduced (P < 0.05) total coliforms in mesenteric lymph nodes on d 21 PI. Pigs in PRO1 had greater (P < 0.05) ileal villi height than pigs in control. Pigs in PRO2 had greater (P < 0.05) sulfomucin percentage in duodenal villi and greater (P < 0.05) sialomucin percentage in jejunal villi than pigs in control. Supplementation of PRO1 also up-regulated (P < 0.05) MUC2 gene expression in jejunal mucosa but reduced (P < 0.05) COX2 and IL1B gene expression in ileal mucosa on d 21 PI, compared with control. In conclusion, supplementation of Bacillus spp. may reduce systemic inflammation and enhance intestinal health of weaned pigs infected with F18 E. coli.