S-layer proteins from lactobacillus paracasei M7 mediated inhibition of Salmonella-induced apoptosis

S-layers are common cell surface structures in many Lactobacillus species and the primary structures of several lactobacillus S-layer proteins are currently known. The objective of this study was to investigate S-lays proteins of L. paracasei M7, which can be used as potential probiotics against pathogens infection. This research is aimed to elucidate if there is a relationship between Salmonella infection and S-lay proteins. Through analysis cell cycle by flow cytometry, the HT-29 cells treated by Salmonella in S phase were 26.88% compared with 36.70% the normal HT-29 cells. However, addition of S-layer proteins made the HT-29 cells in S phase increased to 30.13%. Moreover, we also found that Lactobacillus S-layer proteins could protected Salmonella-induced apoptosis through reduced the caspase-3 activity. This mechanism may represent a novel approach for antagonizing Salmonella infection. So this probiotics could be used in the health-promoting food products, which could prevent the diarrhea caused by Salmonella.