266 - Effects of Lactobacillus Fermentate on Modulation of Mucosa-associated Microbiota in Relation to Intestinal Health of Nursery Pigs Challenged with F18+ Escherichia coli

Abstract: This study investigated the effects of a Lactobacillus fermentate (LBF) on mucosa-associated microbiota and its correlation with intestinal health of pigs challenged with F18⁺ Escherichia coli. Newly-weaned pigs (n = 64; 6.6 ± 0.7 kg BW) were allotted in a randomized complete b;ock design (RCBD) to 4 treatments: NC: no-challenge/no-supplement; PC: E. coli/no-supplement; AGP: E. coli/bacitracin (30 g/t feed); and PBT: E. coli/LBF (2 kg/t feed). At d 7, challenge groups were orally inoculated (2.4 x 10¹⁰ CFU) with F18⁺ E. coli whereas NC received sterile solution. Pigs were fed for 28 d until euthanasia to collect jejunal mucosa to evaluate intestinal health and microbiota. PC reduced (P < 0.05) Selenomonas (1.39 to 0.32%). AGP increased (P < 0.05) Bifidobacteriaceae (0.19 to 2.13%), Burkholderiaceae (0.18 to 1.54%), Comamonadaceae (1.13 to 6.97%), Enterobacteriaceae (0.81 to 2.29%), Microbacteriaceae (0.27 to 1.96%), Moraxellaceae (0.28 to 5.57%), and Pseudomonadaceae (0.36 to 2.59%). PBT increased (P < 0.05) Propionibacteriaceae (0.16 to 3.55%). AGP and PBT increased (P < 0.05) the microbiota diversity (Chao1: 48.8 to 76.4 and 71.6, respectively). Burkholderiaceae and Comamonadaceae were negatively correlated with TNF-α (r = -0.31 and -0.30, respectively; P < 0.05), whereas Burkholderiaceae, Comamonadaceae and Microbacteriaceae were positively correlated with protein carbonyl (r = 0.39, 0.33, and 0.37, respectively; P < 0.05). Bifidobacteriaceae and Pseudomonadaceae were positively correlated with VH:CD (r = 0.41 and 0.40, respectively; P < 0.05), whereas Pseudomonadaceae was positively correlated with villus height (r = 0.34; P < 0.05). Enterobacteriaceae was negatively correlated with G:F (r = -0.41; P < 0.05), whereas positively correlated with IL-8 and MDA (r = 0.39 and 0.32; P < 0.05). Moraxellaceae was negatively correlated with IL-6 (r = -0.29, P < 0.05). Collectively, AGP and LBF increased diversity of beneficial microbiota which was related to improved intestinal health in pigs after E. coli F18⁺ challenge.