β-葡聚糖

β-葡聚糖

β葡聚糖的功能

β葡聚糖是一种纤维形式的聚糖（多聚糖），从贝克酵母、燕麦和大麦纤维和许多医用蘑菇的细胞壁中分解而来。在它们的天然成分中，酵母和蘑菇含有一种β-1，3-葡聚糖和β-1，6-葡聚糖的混合体。燕麦和大麦则包含有β-1，3-葡聚糖和β-1，4葡聚糖的混合体。除了纯化的β-1，3-葡聚糖，市场上可以看到从酵母中得来的列有β-1，3葡聚糖/1，6-葡聚糖和从燕麦中得来的β-1，3-葡聚糖/1，4-葡聚糖。类似的特性还可体现在从燕麦、酵母和蘑菇中得来的富含β-葡聚糖的提取物和纯化β葡聚糖。这两种主要的β葡聚糖可用于增强免疫力和降低血胆固醇水平。大量的试管试验和动物试验表明β葡聚糖可以激活白细胞^{[1 2 3 4 5]}。实际上，从1960年开始已有大量的关于β葡聚糖的研究^[6]。这些研究指出β-1，3-葡聚糖对于激活白细胞中的巨噬细胞和中性粒细胞有很强的作用。这些细胞作为人体免疫系统的第一防御线能有效的抵御外来侵入。葡聚糖继获得巨噬细胞和中性粒细胞可以识别和杀灭肿瘤细胞、清除氧化损害的细胞残骸，加速回复受损组织以及激活免疫系统的其他部分。^{[7 8]}尽管动物试验和试管试验体现出很好的前景，但仍有许多关于β葡聚糖作为口服补充剂增强免疫功能的有效性问题未能解决。

β葡聚糖是燕麦降低胆固醇作用的主要因子。^{[9 10 11 12 13]}和其他可溶纤维及胆固醇（胆汁酸）联合在一起时，β葡聚糖可以清除粪便中的这些分子，从而对于降低血胆固醇有一定帮助^{[14 15 16]}。许多关于燕麦或酵母提取出的β葡聚糖的双盲试验得出，4周后可以降低10%的总胆固醇和8%的低密度脂蛋白（有害的），以及将高密度脂蛋白（有益的）从0提高到16%。^{[17 18 19 20 21]}

和其他可溶性纤维一样，在以前的试验中可看到，β葡聚糖对于降低餐后血糖有一定帮助。^{[22 23 24 25]}β葡聚糖通过延缓胃的排空来改善糖的吸收，同时还可能提高了组织对胰岛素的敏感性。这些作用对于糖尿病人的血糖控制有一定的功效。

β葡聚糖的分布

许多酵母和谷类如燕麦、大麦的细胞壁中含有β葡聚糖。作为饮食补充，β葡聚糖可作为流质、胶囊和药片服用。

β葡聚糖认为与以下疾病有关（以下所有信息适用于个体化健康情况）：

哪些人可能会缺乏β葡聚糖？

因为β葡聚糖不是必需营养素，所以不存在缺乏。

一般需要多少β葡聚糖？

为了降低胆固醇水平，β葡聚糖在临床试验中的剂量为每天2900~15000毫克。为了增强免疫力，有效的剂量还缺乏试验支持。可是，厂家们生产的β葡聚糖通常在每天50~1000毫克（空腹服用），另外还有些胶囊制成500毫克。

是否有副作用和药物相互作用？

还没有关于β葡聚糖副作用的报道。

到目前为止，还不知道β葡聚糖与其他药物间的相互作用。

参考文献

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