159 Impact of dietary fiber and carbohydrases on intestinal gene transcription in enterotoxigenic E. coli challenged pigs

Abstract

Abstract This study aimed to evaluate if soluble (10% sugar beet pulp) or insoluble dietary fiber (15% corn DDGS) with or without exogenous carbohydrases protect piglets against enterotoxigenic E. coli (ETEC)-induced changes in gene transcription of markers of intestinal inflammation and barrier integrity. Sixty newly-weaned piglets (BW=6.9 ± 0.1 kg; L337 X Camborough, PIC, Hendersonville, TN) were blocked by initial BW, preselected for F18 ETEC sensitivity and placed in individual pens. Pens were randomly assigned to 1 of 6 treatments (n = 10/trt): non-challenged (NC), ETEC-challenged (PC), PC-fed a soluble fiber diet without (SF-) or with (SF+) carbohydrases (xylanase, β-glucanase, and pectinase), or PC fed an insoluble fiber diet without (IF-) or with carbohydrases (IF+). Pigs were orally inoculated with ETEC or PBS on d 7 post-weaning. Intestinal tissues were collected on d 14 or 15. Data were analyzed using PROC GLIMMIX (SAS 9.4); treatment was a fixed effect and block a random effect. The NC decreased interleukin (IL)-8 and increased claudin-1 (CLDN1; 2.32 vs. 0.96) mRNA abundance in the ileum compared to PC (P < 0.05). The SF- increased ileal CLDN1 mRNA compared to PC (P < 0.05). A trend (P < 0.10) for lower levels of tumor necrosis factor alpha (TNFα) and greater occludin (OCLN) mRNA in the ileum was observed in SF+ compared with PC. The IF+ decreased ileal cluster of differentiation 14 (CD14) mRNA abundance compared to PC (P < 0.05). Greater colonic abundance of zonula occludens (ZO-1) mRNA was observed in NC than PC (P < 0.05). Pigs fed SF+ tended (P = 0.051) to have greater ZO-1 and greater OCLN mRNA abundance than pigs on PC (P < 0.05). Collectively, these data suggest that an ETEC challenge increased markers of gut inflammation and reduced mRNA levels of tight junction proteins. Soluble fiber, regardless of enzyme supplementation, may help improve gut barrier integrity during such a challenge.