Introduction of prebiotics and probiotics as daily food supplements is believed to be a promising
way of controlling enteric or other chronic infections and improving gut health. In this
study, the effects of Lactobacillus casei on growth and virulence properties of foodborne enteric
bacterial pathogens enterohemorrhagic Escherichia coli EDL933, Salmonella Typhimurium LT2,
and Listeria monocytogenes LM2 were investigated.Mixed culture of L. casei with each of these
pathogens showed that L. casei could competitively exclude or inhibit the growth of pathogens
by >99% within 48 h. Further investigation revealed that the antimicrobial byproducts
produced by L. casei in cocoa pre-treated cultural supernatant significantly reduced the growth,
increased the hydrophobicity values, blocked the interaction with human intestinal epithelial
cell (INT-407), and altered the virulence genes expression of these bacterial pathogens.
These results suggest the possibility of applying L. casei with cocoa in preventing/reducing
foodborne pathogen infections in gut environment.