In vitro screening of non-antibiotic components to mitigate intestinal lesions caused by Brachyspira hyodysenteriae, Lawsonia intracellularis and Salmonella enterica serovar Typhimurium.

Backgrounds: wine dysentery, ileitis, and porcine salmonellosis are production-limiting diseases global importance in swine production. They are caused by infection with Brachyspira hyodysenteriae , Lawsonia intracellularis , and Salmonella enterica serovar Typhimurium, respectively. Currently, the prevention, treatment, and control of these diseases still rely on antimicrobials. The goal of this study was to evaluate the effectiveness of four commercially available non-antimicrobial compounds in preventing lesions caused by the bacteria cited above using an in vitro intestinal culture model. A total of five pigs per pathogen were used. For compounds F (a fungal fermented rye), S (a blend of short and medium chain fatty acids) and P (a synergistic blend of short and medium chain fatty acids, including coated butyrates) a total of 4 explants/pig for each treatment were used, while for compound D (an extract of carob and thyme) only 12 explants/pig for each treatment were used. Explants were exposed to a combination of pathogen only (n = 4/compound/pig), compound only (n = 4/compound/pig) or pathogen and compound (n = 4/compound/pig) and sampled a two time-points. Histopathology and gene expression levels were evaluated to investigate the treatment effect on exaplnts. Results: short and medium-chain fatty acids, and an extract of carob and thyme can mitigate lesions due to B. hyodysenteriae exposure. A fungal fermented prebiotic increased healthy epithelial coverage when explants were exposed to L. intracellularis or S. Typhimurium. Conclusions: these findings are a step towards finding alternatives to antimicrobials usage and control of swine dysentery, ileitis, and salmonellosis in pork production.