The objective of this study was to evaluate the significance of jejunal mucosa-associated microbiota and its impacts on the intestinal health of pigs challenged with F18+ Escherichia coli. Forty-four newly-weaned pigs were allotted to two treatments in a randomized complete block design with sex as blocks. Pigs were fed common diets for 28 d. At d 7 post-weaning, pigs were orally inoculated with saline solution or F18+ E. coli. At d 21 post-challenge, feces and blood were collected and pigs were euthanized to collect jejunal tissue to evaluate microbiota and intestinal health parameters. The relative abundance of Firmicutes and Bacteroidetes was lower (p < 0.05) in jejunal mucosa than in feces, whereas Proteobacteria was greater (p < 0.05) in jejunal mucosa. F18+ E. coli increased (p < 0.05) protein carbonyl, Helicobacteraceae, Pseudomonadaceae, Xanthomonadaceae, and Peptostreptococcaceae and reduced (p < 0.05) villus height, Enterobacteriaceae, Campylobacteraceae, Brachyspiraceae, and Caulobacteraceae in jejunal mucosa, whereas it reduced (p < 0.05) Spirochaetaceae and Oscillospiraceae in feces. Collectively, jejunal mucosa-associated microbiota differed from those in feces. Compared with fecal microbiota, the change of mucosa-associated microbiota by F18+ E. coli was more prominent, and it was mainly correlated with increased protein carbonyl and reduced villus height in jejunal mucosa impairing the intestinal health of nursery pigs.
Keywords: F18+ Escherichia coli; intestinal health; mucosa-associated microbiota; nursery pigs.