L. monocytogenes challenge protocols were modified methods click here of Irons et al. (27) and Puertollano et al. (28). Five mice in each group

were given a daily dose of 1 × 109 cfu viable LGG or JWS 833 in 100 μL PBS containing 10% skim milk via an intra-gastric tube for 2 weeks. The NC and PC groups were given 100 μL PBS containing 10% skim milk. After 2 weeks, both the LAB-fed groups and the PC group were infected with L. monocytogenes (1.2 × 105 cfu in 100 μL PBS) via their tail veins. The NC group was injected with 100 μL PBS alone. All housing and handling was according to the regulations of the Animal Care and Ethics Committee of Chungbuk National University and was in compliance with the guidelines of the Committee for Institutional Animal Care and Use for Scientific Purposes. Three days after challenge with L. monocytogenes, the mice were killed and weighed. Their livers and spleens were also weighed and serum collected. Liver and spleen weights relative to body weight were calculated. The livers were aseptically homogenized by passage through a 70 μm nylon mesh (Fisher Scientific, PA, Pittsburgh, USA) and the number of viable L. monocytogenes cells on the BHI plates counted. The results were expressed as log data. Mice sera were analyzed for NO and cytokines (IL-1β

and TNF-α). Ten mice per group were fed LAB or PBS containing 10% skim milk for 2 weeks before infection with L. monocytogenes as described above. The survival rate was then monitored every 8 hrs until death. Data were analyzed using SPSS for Windows NVP-BKM120 cost Version 12.0 (SPSS, Chicago, IL, USA). Significant differences between the LAB and control groups were tested by analysis of variance and compared using Tukey’s and Duncan’s multiple range tests. A P value < 0.05 was considered significant. We measured heat-killed JWS 833-induced production

of NO and cytokines (IL-1β and TNF-α) by activated peritoneal macrophages in vitro to examine the immunomodulatory properties of JWS 833. Although both heat-killed LAB strains induced NO production, JWS 833 induced higher concentrations than LGG (Fig. 1a). Org 27569 LGG induced 0.91 ± 0.04 μM/mL and 1.48 ± 0.29 μM/mL at 1 × 107 and 5 × 107 cfu/mL, respectively. These results were not significantly different from those of the PBS controls (0.79 ± 0.07 μM/mL). However, the concentration of NO induced by JWS 833 was higher than by LGG at the above concentrations. Moreover, the concentration of NO induced by 5 × 107 cfu/mL of JWS833 was similar with LPS stimulation. Lactic acid bacteria induced IL-1β production in a dose-dependent manner (Fig. 1b). JWS 833 was better at inducing IL-1β than LGG. LGG (1 × 107 cfu/mL) induced concentrations of IL-1β similar to those induced in the NCs (20.61 ± 1.77 pg/mL vs. 15.00 ± 0.27 pg/mL). In contrast, JWS 833 (1 × 107 cfu/mL) induced 196.41 ± 3.44 pg/mL, about 10-fold higher than LGG or the NC for the same concentration.