Screening the probiotics inhibiting the diarrhea caused by pathogens

In this study, fourteen selected Lactobacillus isolated from human intestinal and ferment milk were assessed the ability to inhibit the infection of enteropathogens. The Lactobacillus strains were screened on the basis of probiotic characteristics (i.e., resistance to low p H and bile salts, adhesion to the human gastrointestinal tract) . By an in vitro system simulating gastric transit, it indicated that the three probiotic strains had the ability to tolerate gastroenteric environment and the adhesive capacity to HT-29 cells. It was demonstrated that the number of 7 probiotics strains could reach about 107CFU/m L after treatment of 90 min in p H2 and the number of bacteria strains decreased to one percent of the original after treatment of 0.3% of the bile salt environment 2h.Adhesion of probiotics on number of J5, G15 and F0533 could reach 106CFU/m L, which showed strong adhesion ability. Among the selected strains, five selected Lactobacillus showed a high probiotic potential and could be used in health-promoting food products. After analyzing the sequence of the 16 S r DNA regions of these strains, five potential probiotic F0533, IN4125, G15, J5 and M7 were Lactobacillus rhamnosus, Lactobacillus rhamnosus, Lactobacillus paracasei, Lactobacillus casei and Lactobacillus paracasei.