乳酸菌對人體免疫力的影響與機制之探討

Effects and Functional Mechanisms of Lactic Acid Bacteria on Human Immunity

唐嘉芳(Chia-Fang Tang)

指導教授 ： 謝明哲 ； 商惠芳 ； 劉珍芳

臺北醫學大學/公共衛生暨營養學院/保健營養學研究所/碩士(2002年)

摘要

本研究係在探討攝取乳酸菌－Bifidobacterium longum BB536, Bifidobacterium lactis Bb12, Lactobacillus acidophilus, Lactobacillus casei, 及Enterococcus faecium對人體免疫力的影響與可能之免疫反應途徑。實驗採單盲方式，受試者共27位健康成人，平均年齡24.5歲。實驗期包括四個階段：第一期為適應期，為期一週，受試者開始禁止攝取任何含有乳酸菌的製品；第二期為期三週，受試者每日攝取6顆安慰劑（placebo tablet）；第三期為期三週，受試者每日攝取6顆乳酸菌錠（LAB tablet），內含上述五種乳酸菌粉，活菌數>109CFU；第四期為排空期，為期二週。由受試者於實驗每期的飲食記錄與糞便中菌數的檢定，發現受試者順應性良好。每一實驗期結束當天，分別收取：(1)唾液樣本－用於分析secretary IgA；(2)血液樣本－用於分析一般生化值、血清抗體IgA濃度、血液多核球（granulocytes）與單核球（monocytes）的吞噬能力（phagocytic activity）、淋巴細胞亞型（Lymphocyte subsets－helper T cells, cytotoxic T cells, B lymphocytes＆NK cells）的比例、自然殺手細胞（NK cells）活性，並以phytohaemagglutinin (PHA)、lipopolysaccharide (LPS)及Concanavalin A(Con A)等mitogens分別刺激淋巴細胞後，檢測淋巴細胞的增殖反應。 本實驗研究結果發現：攝取乳酸菌後，sIgA及IgA濃度明顯增加(P<0.05)、血液多核球與單核球的吞噬能力明顯增加(P<0.0001)、自然殺手細胞比例與毒殺力亦較攝取前明顯增加(P<0.05 ＆ P<0.0001)，除自然殺手細胞外之淋巴細胞亞型比例與淋巴細胞的增殖反應則無明顯變化。綜合上述，攝取乳酸菌－B. longum BB536、B. lactis Bb12、L. acidophilus、L casei及E. faecium，可調節人體吞噬細胞吞噬能力與NK細胞毒殺力等非特異性免疫反應（non-specific immune response），與sIgA分泌等黏膜性免疫反應（mucosal immune response），而達到增強免疫力的作用。

關鍵字

乳酸菌 ； 吞噬作用 ； 自然殺手細胞 ； 淋巴細胞亞型分布 ； 淋巴細胞增殖反應 ； sIgA ； 免疫反應

並列摘要

The aim of present study was to examine the effects and possible mechanisms of oral administration of Bifidobacterium longum BB536, Bifidobacterium lactis Bb12, Lactobacillus acidophilus, Lactobacillus casei, and Enterococcus faecium on human immunity. The experimental design was single-blind and placebo controlled trial. Twenty seven healthy volunteers (age from 20 to 30 y; mean 24.5±2.5 y) participated in this 4-period trial for 9 wks. During the first week, subjects were asked to avoid any probiotic products, and then they consumed placebo (six tablets once a day) for 3 wks as a placebo control. During the 3rd period, they consumed six LAB (lactic acid bacteria) tablets, which contained the 5 strains of lactobacilli with viable counts more than 109 CFU, once a day for 3wks. Finally, the 4th period was washout for another 3 wks. All subjects had good compliance confirmed by their diet records and fecal bacterial counts throughout the trial. Both the saliva sample for sIgA analysis and the peripheral blood were obtained from subjects at the end of each period. The peripheral blood was for analysis of complete blood cell count, blood chemistry panel, serum IgA, phagocytic activity of granulocytes and monocytes, lymphocyte subpopulation (helper T cells, cytotoxic T cells, B lymphocytes and NK cells), NK-cell activity, and the proliferation of lymphocytes after stimulating by mitogens LPS, PHA, and Con A. The results indicated that the concentrations of sIgA and serum IgA, phagocytic activity of granulocytes and monocytes, and the cytotoxicity and ratio of NK cell increased significantly after consumption of LAB tablets. However, neither the lymphocyte subpopulation (except NK cell) nor lymphocyte proliferation had significant difference. In summary, this study showed that oral consumption of Bifidobacterium longum BB536, Bifidobacterium lactis Bb12, Lactobacillus acidophilus, Lactobacillus casei, and Enterococcus faecium did efficiently enhance human immunity by modulating their non-specific and mucosal immune response.

並列關鍵字

LAB ； phagocytosis ； NK cells ； lymphocyte subpopulation ； lymphocyte proliferation ； sIgA ； immune response

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