| Summary: | 碩士 === 輔仁大學 === 食品營養學系 === 91 === The purposes of this study were to investigate the effect of probiotics on immune functions by RAW264.7 murine macrophage cell line and BALB/c mice. By means of measuring cytokine production, RAW264.7 cells and PEC of BALB/c mice were cultured with 10 strains of heat-killed Bifidobacterium spp., Lactobacillus spp. and Streptocccus thermophilus CCRC14087 cells, to evaluate the effect of probiotics on the stimulation of immune function. The PEC cells were more suitable to evaluate the effects of probiotics on immune response than RAW264.7 cells. Bifidobacterium adolescentis CCRC14606 exhibited stronger augmentation of immune response than other strains tested. The amount of TNF-α (tumor necrosis factor-α), IL-6 (interleukin-6) and IL-1β (interleukin-1β) production increased with increasing concentration of bacteria, with maximum at the level of 108 CFU/ml. Milk and fermented milk containing B. adolescentis CCRC14606 were orally administered to BALB/c mice for two weeks, to investigate the systemic and mucosal intestinal immune response. Results showed that the production of mucosal intestinal IgA and serum IgG increased in mice which were fed with fermented milk. The phagocytic activity of granulocytes in the peripheral blood and NK cell cytotoxicity of peritoneal cavity were also significantly increased in mice fed with fermented milk. The production of TNF-α and IL-6 by PEC cells were higher in mice fed with milk containing live B. adolescentis CCRC14606 and fermented milk. In response to LPS (a B-cell mitogen) stimulation, the proliferation of MLN (mesenteric lymph node) cells was significantly increased in mice fed with fermented milk. Cytokines such as IL-2 produced by Con A-induced of MLN cells was increased in mice fed with milk containing live B. adolescentis CCRC14606 and fermented milk. However, IFN-γ production in each group was lower than that in the control. In contrast, level of type Ⅱ helper T lymphocytes-related cytokines, such as IL-10 were enhanced in mice fed with fermented milk. B. adolescentis CCRC14606 fermented milk showed stronger activation of immune function of mice than milk containing live B. adolescentis CCRC14606. In addition, fermented milk fermented milk had inducement of immune response than heat-treated fermented milk. These data suggested that oral administration of milk containing live probiotics and particularly fermented milk for 2 weeks markedly enhanced systemic and mucosal intestinal immune response by BALB/c mice.
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