Lampe J W, Karr S C, Hutchins A M, Slavin J L
Cancer Prevention Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA.
Proc Soc Exp Biol Med. 1998 Mar;217(3):335-9. doi: 10.3181/00379727-217-44241.
Equol is an isoflavonoid phytoestrogen produced from the soy isoflavone daidzein by gut microflora. Not all humans produce equol from daidzein, presumably due to differences in colonic bacterial populations among individuals. Previously, smaller studies reported that approximately 30% of participants excreted equol when consuming soy. The purpose of our study was to determine the prevalence of equol excreters in a larger sample and to examine what dietary components might influence the tendency to be an equol excreter. Thirty men and thirty women consumed a soy protein beverage containing 22 mg genistein and 8 mg daidzein for 4 days as a supplement to their habitual diets. The mean daily nutrient content of their habitual intakes was determined from 4-day food records. On Day 4, participants provided a 24-hour urine collection. Urinary isoflavonoid (genistein, daidzein, equol, and O-desmethylangolensin) excretion was measured by gas chromatography-mass spectrometry. Twenty-one of the 60 participants (35%) excreted equol (> 2000 nmol/day) after 3 days of consuming the soy supplement. Daily equol excretion ranged from 2,134-20,301 nmol/day in the excreters and 21-233 nmol/day in the nonexcreters. There was no difference in equol excreter prevalence between men (43%) and women (27%). Daily excretion of daidzein, genistein, and O-desmethylangolensin was similar between equol excreters and nonexcreters and between men and women. Among the women, equol excreters consumed a significantly higher percentage of energy as carbohydrate and greater amounts of plant protein and dietary fiber, both as soluble and insoluble fiber compared to nonexcreters. Such differences were not observed in the men, who overall had significantly higher fiber intakes than the women. These data suggest that, among women, dietary fiber or other components of a high-fiber diet may promote the growth and/or the activity of bacterial populations responsible for equol production in the colon.
雌马酚是一种异黄酮类植物雌激素，由肠道微生物群从大豆异黄酮黄豆苷原转化而来。并非所有人都能从黄豆苷原产生雌马酚，这可能是由于个体之间结肠细菌种群存在差异。此前，规模较小的研究报告称，约30%的参与者在食用大豆时会排出雌马酚。我们研究的目的是在更大的样本中确定雌马酚排泄者的比例，并研究哪些饮食成分可能影响成为雌马酚排泄者的倾向。30名男性和30名女性将一种含有22毫克染料木黄酮和8毫克黄豆苷原的大豆蛋白饮料作为日常饮食的补充剂，连续饮用4天。他们日常饮食的平均每日营养成分是根据4天的食物记录确定的。在第4天，参与者收集24小时尿液。通过气相色谱-质谱法测量尿液中异黄酮（染料木黄酮、黄豆苷原、雌马酚和O-去甲基安哥拉紫檀素）的排泄量。60名参与者中有21人（35%）在食用大豆补充剂3天后排出了雌马酚（>2000纳摩尔/天）。排泄者的每日雌马酚排泄量在2134至20301纳摩尔/天之间，非排泄者的排泄量在21至233纳摩尔/天之间。男性（43%）和女性（27%）的雌马酚排泄者比例没有差异。雌马酚排泄者和非排泄者之间以及男性和女性之间，黄豆苷原、染料木黄酮和O-去甲基安哥拉紫檀素的每日排泄量相似。在女性中，与非排泄者相比，雌马酚排泄者摄入的碳水化合物能量百分比显著更高，并且摄入了更多的植物蛋白和膳食纤维，包括可溶性纤维和不可溶性纤维。在男性中未观察到此类差异，男性的纤维摄入量总体上显著高于女性。这些数据表明，在女性中，膳食纤维或高纤维饮食的其他成分可能会促进结肠中负责产生雌马酚的细菌种群的生长和/或活性。
