ABSTRACT
The probiotic properties and inhibitory effect on Salmonella Typhimurium adhesion on human enterocyte-like HT-29-Luc cells of three Lactobacillus plantarum strains isolated from fermented fish, beach sand and a coastal plant were determined. Compared with the type strain L. plantarum NBRC 15891T, which was isolated from pickled cabbage, L. plantarum Tennozu-SU2 isolated from the acorn of a coastal tree showed high autoaggregation in de Man, Rogosa and Sharpe (MRS) broth and an antagonistic effect against S. Typhimurium in brain heart infusion (BHI) broth. Furthermore, heat-killed L. plantarum Tennozu-SU2 cells inhibited S. Typhimurium adhesion on HT-29-Luc cells. Both live and heat-killed L. plantarum Tennozu-SU2 cells showed an inhibitory effect on gut colonisation in BALB/c mice, as assessed by viable Salmonella count in faecal samples and by invasion into liver and spleen tissues. The properties shown in this study suggest that L. plantarum Tennozu-SU2 is useful as a starter and probiotic bacteria in functional food material.
Subject(s)
Brassica/microbiology , Enterocytes/drug effects , Lactobacillus plantarum/physiology , Probiotics/administration & dosage , Salmonella Infections/drug therapy , Salmonella typhimurium/physiology , Animals , Bacterial Adhesion/drug effects , Enterocytes/microbiology , Feces/microbiology , HT29 Cells , Humans , Liver/microbiology , Male , Mice , Mice, Inbred BALB C , Salmonella Infections/microbiologyABSTRACT
Oxidative stress is considered an etiological factor responsible for several symptoms of inflammatory bowel disease (IBD). In vitro anti-inflammatory activities of heat-killed Lactococcus lactis subsp. lactis BF3 have been reported. In this study, the anti-inflammatory effect of these cells was examined using a dextran sodium sulphate (DSS)-induced murine IBD model. Administration of heat-killed L. lactis BF3 via drinking water suppressed the IBD symptoms, such as shortening of colon length, damage to the colon mucosa as observed under the microscope, and spleen enlargement. This result suggests that heat-killed L. lactis BF3 has the potential to treat IBD.
ABSTRACT
Brown algal polysaccharides such as alginate, polymers of uronic acids, and laminaran, beta-1,3 and 1,6-glucan, can be fermented by human intestinal microbiota. To evaluate the effects of these polysaccharides on infections caused by food poisoning pathogens, we investigated the adhesion and invasion of pathogens (Salmonella Typhimurium, Listeria monocytogenes and Vibrio parahaemolyticus) in human enterocyte-like HT-29-Luc cells and in infections caused in BALB/c mice. Both sodium Na-alginate and laminaran (0.1% each) inhibited the adhesion of the pathogens to HT-29-Luc cells by approximately 70-90%. The invasion of S. Typhimurium was also inhibited by approximately 70 and 80% by Na-alginate and laminaran, respectively. We observed that incubation with Na-alginate for 18 h increased the transepithelial electrical resistance of HT-29-Luc monolayer cells. Four days after inoculation with 7 log CFU/mouse of S. Typhimurium, the faecal pathogen count in mice that were not fed polysaccharides (control mice) was about 6.5 log CFU/g while the count in mice that were fed Na-alginate had decreased to 5.0 log CFU/g. The liver pathogen count, which was 4.1 log CFU/g in the control mice, was also decreased in mice that were fed Na-alginate. In contrast, the mice that were fed laminaran exhibited a more severe infection than that exhibited by control mice.
