Effects of probiotics on growth performance, intestinal morphology, intestinal microbiota weaning pig challenged with Escherichia coli and Salmonella enterica

This study aimed to evaluate the effects of mono- and multi-strain LAB probiotics on the growth performance, nutrient digestibility, blood profiles, fecal noxious gas emission, intestinal microbiota and intestinal morphology of weaning pigs challenged with or without <italic>Escherichia coli (E. coli)</italic> and <italic>Salmonella enterica (</italic>SE<italic>)</italic>. In Exp. 1, a total of 60 crossbred weaning pigs were randomly allotted to one of five dietary treatments. The dietary treatments included: NC (negative control; basal diet with no supplement), PC (positive control; basal diet with 0.01% <italic>Lactiplantibacillus plantarum </italic>(LP) containing 1.0 × 10⁸ CFU/g), K (basal diet with 0.1% <italic>Pediococcus acidilactici</italic> K (K) containing 1.0 × 10⁹ CFU/g), WK1 (basal diet with 0.1% <italic>Pediococcus pentosaceus</italic> SMFM2016-WK1 (WK1) containing 1.0 × 10⁹ CFU/g), K-WK1 (basal diet with 0.05% K + 0.05% WK1 containing 1.0 × 10⁹ CFU/g). The average daily gain (ADG) was higher in the K group than in the WK1 group. Diarrhea score was lower in the K-WK1 group than in the NC group. At the genus level, <italic>Roseburia</italic> abundance in WK1 was higher than in the other treatment groups. At the species level, <italic>Blautia wexlerae</italic> abundance was lower in WK1 than in the other groups, whereas <italic>Succinivibrio dextrinosolvens</italic> abundance was higher in WK1. The serum pro-inflammatory cytokine levels in the PC and WK1 groups were as low as those in the NC group. Experiment 2 was conducted with two trials in a 2 × 5 factorial arrangement of treatments consisting of two levels of challenge (challenge and non-challenge) with <italic>E. coli</italic> and SE and five levels of probiotics same as Exp.1. Supplementation with LP and WK1 resulted in higher ADG and lower diarrhea scores than those in the other groups. Consequently, supplementation of WK1 showed a particularly positive effect on growth performance and diarrhea, villus height and intestinal microbiota in oral challenge experiment and feeding trial. Therefore, WK1 might be the most effective among the probiotics used in this experiment.