Coulman Karen D, Liu Zhen, Hum Winston Quan, Michaelides John, Thompson Lilian U
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
Nutr Cancer. 2005;52(2):156-65. doi: 10.1207/s15327914nc5202_6.
The mammalian lignans enterolactone and enterodiol, which are produced by the microflora in the colon of humans and animals from precursors in foods, have been suggested to have potential anticancer effects. This study determined the production of mammalian lignans from precursors in food bars containing 25 g unground whole flaxseed (FB), sesame seed (SB), or their combination (FSB; 12.5 g each). In a randomized crossover study, healthy postmenopausal women supplemented their diets with the bars for 4 wk each separated by 4-wk washout periods, and urinary mammalian lignan excretion was measured at baseline and after 4 wk as a marker of mammalian lignan production. Results showed an increase with all treatments (65.1-81.0 mumol/day; P < 0.0001), which did not differ among treatments. Lignan excretion with the whole flaxseed was similar to results of other studies using ground flaxseed. An unidentified lignan metabolite was detected after consumption of SB and FSB but not of FB. Thus, we demonstrated for the first time that 1) precursors from unground whole flaxseed and sesame seed are converted by the bacterial flora in the colon to mammalian lignans and 2) sesame seed, alone and in combination with flaxseed, produces mammalian lignans equivalent to those obtained from flaxseed alone.
哺乳动物木脂素肠内酯和肠二醇由人和动物结肠中的微生物群利用食物中的前体物质产生，据推测具有潜在的抗癌作用。本研究测定了含有25克未研磨的全亚麻籽（FB）、芝麻籽（SB）或其组合（FSB；各12.5克）的食物棒中前体物质产生哺乳动物木脂素的情况。在一项随机交叉研究中，健康的绝经后女性在饮食中补充这些食物棒，每次为期4周，中间间隔4周的洗脱期，并在基线期和4周后测量尿中哺乳动物木脂素的排泄量，以此作为哺乳动物木脂素产生的标志物。结果显示，所有处理组的排泄量均增加（65.1 - 81.0微摩尔/天；P < 0.0001），各处理组之间无差异。全亚麻籽的木脂素排泄量与其他使用研磨亚麻籽的研究结果相似。食用SB和FSB后检测到一种未鉴定的木脂素代谢物，但食用FB后未检测到。因此，我们首次证明：1）未研磨的全亚麻籽和芝麻籽中的前体物质被结肠中的细菌菌群转化为哺乳动物木脂素；2）芝麻籽单独或与亚麻籽组合时产生的哺乳动物木脂素与仅从亚麻籽中获得的相当。
