Abstract:

This research aimed to study the mechanism of orally administered probiotics Escherichia coli（E.coli） Nissle 1917 regulating intestine barrier in weaned piglets challenged or unchallenged by enterotoxigenic E.coli Abbottstown.Twenty piglets with an average live body weight of (6.35±0.58) kg randomly assigned to 4 treatments:(1) Weaned piglets were provided a based diet (CON);(2) Weaned piglets were orally administered probiotics E.coli Nissle 1917 in the test (EcN);(3) Weaned piglets were challenged by enterotoxigenic E.coli Abbottstown in the pre-test (EcA);(4) Weaned piglets were challenged by enterotoxigenic E.coli Abbottstown in the pre-test and orally administered probiotics E.coli Nissle 1917 (EcN+EcA) in the test.Each treatment had one repeat and one repeat had one piglet.This experiment had a 3 d pre-test and 21 d test.Weaned piglets in the EcA and EcN+EcA groups were challenged by 5×10⁹ enterotoxigenic E.coli Abbottstown in the pre-test (EcA).Weaned piglets in the EcN and EcN+EcA groups were daily orally administered probiotics 1×10¹⁰ E.coli Nissle 1917 in the test.The results showed as follows:Compared with the CON group,orally administered 1×10¹⁰ probiotics E.coli Nissle 1917 could improve growth performance (P<0.05),decrease diarrhea ratio,increase the concentration of occludin (P<0.05),decrease the concentration of calprotectin (P<0.05),down-regulate the mRNA expression levels of Protein kinase R (PKR),Toll-like receptor-2 (TLR-2) and eukaryotic initiation factor-5A (eIF-5A) (P<0.05),and up-regulate the mRNA expression levels of Endothelial growth factor (EGF),Hepatocyte growth factor (HGF),Insulin-like growth factor (IGF-I),Trefoil peptide factor-3 (TFF-3) (P<0.05) in jejunal mucous membrane in weaned piglets unchallenged by enterotoxigenic E.coli Abbottstown;Compared with the EcA group,orally administered 1×10¹⁰ probiotics E.coli Nissle 1917 could improve growth performance (P<0.05),decrease diarrhea ratio,decrease serum concentration of DAO (P<0.05) and NO (P<0.05),increase the
concentration of occludin (P<0.05),decreased the concentration of calprotectin (P<0.05),down-regulate the mRNA expression levels of PKR,eIF-5A and TLR-2 (P<0.05),and up-regulate the mRNA expression levels of IGF-I,HGF,TFF-3 and EGF (P<0.05) in jejunal mucous membrane in weaned piglets challenged by enterotoxigenic E.coli Abbottstown.These results indicate that orally administered 1×10¹⁰ probiotics E.coli Nissle 1917 can protect greatly the intestinal barrier of early weanling piglets challenged or unchallenged by enterotoxigenic E.coli Abbottstown.