Nettleton Jennifer A, Greany Kristin A, Thomas William, Wangen Kerry E, Adlercreutz Herman, Kurzer Mindy S
Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55108, USA.
J Altern Complement Med. 2005 Dec;11(6):1067-74. doi: 10.1089/acm.2005.11.1067.
Observational studies suggest that dietary isoflavones reduce breast cancer risk, and this may be caused in part by effects on endogenous hormone concentrations. Because intestinal bacteria metabolize isoflavones, it was hypothesized that consumption of probiotic bacteria would enhance the biologic effects of isoflavones, including effects on endogenous hormones.
Twenty (20) postmenopausal breast cancer survivors and 20 healthy postmenopausal women completed four 42-day diet periods in a randomized, crossover design. They received one of the following: isolated soy protein; isolated milk protein; soy + probiotic capsules; or milk + probiotic capsules. Each protein supplement provided 0.38 g protein/(kg body weight/day) (26.6 +/- 4.5 g protein/day) and soy protein provided 0.64 mg isoflavones/(kg body weight/day) (44.4 +/- 7.5 mg isoflavones/day). Probiotic capsules provided 10(9) colony-forming units Lactobacillus acidophilus (strain DDS-1), Bifidobacterium longum, and 15-20 mg fructo-oligosaccharide.
Plasma samples were collected at baseline and after each diet for analysis of estrogens, follicle-stimulating hormone (FSH), androgens, and sex hormone?binding globulin (SHBG).
Hormone levels were not affected by soy, probiotic supplements, or equol producer status, and neither cancer status nor equol producer status altered the effects of soy or probiotics. Furthermore probiotics did not alter the effects of soy consumption. Soy protein tended to decrease SHBG compared to milk protein diets (p = 0.05), although both proteins significantly decreased SHBG relative to baseline (p = 0.0001 and p = 0.03).
These data suggest that short-term, moderate consumption of isoflavone-containing soy protein and consumption of these particular probiotic capsules do not significantly alter reproductive hormone concentrations in breast cancer survivors or controls, regardless of equol producer status.
观察性研究表明，膳食异黄酮可降低乳腺癌风险，这可能部分归因于其对体内激素浓度的影响。由于肠道细菌可代谢异黄酮，因此推测食用益生菌会增强异黄酮的生物学效应，包括对体内激素的影响。
20名绝经后乳腺癌幸存者和20名健康绝经后女性采用随机交叉设计完成了4个为期42天的饮食阶段。她们分别接受以下一种处理：分离大豆蛋白；分离乳蛋白；大豆+益生菌胶囊；或牛奶+益生菌胶囊。每种蛋白质补充剂提供0.38克蛋白质/（千克体重/天）（26.6±4.5克蛋白质/天），大豆蛋白提供0.64毫克异黄酮/（千克体重/天）（44.4±7.5毫克异黄酮/天）。益生菌胶囊提供10⁹个嗜酸乳杆菌（菌株DDS-1）、长双歧杆菌的菌落形成单位，以及15 - 20毫克低聚果糖。
在基线期和每个饮食阶段结束后采集血浆样本，用于分析雌激素、促卵泡激素（FSH）、雄激素和性激素结合球蛋白（SHBG）。
激素水平不受大豆、益生菌补充剂或雌马酚产生状态的影响，癌症状态和雌马酚产生状态均未改变大豆或益生菌的作用。此外，益生菌并未改变大豆消费的影响。与乳蛋白饮食相比，大豆蛋白倾向于降低SHBG（p = 0.05），尽管两种蛋白质相对于基线均显著降低了SHBG（p = 0.0001和p = 0.03）。
这些数据表明，短期适度食用含异黄酮的大豆蛋白以及食用这些特定的益生菌胶囊，无论雌马酚产生状态如何，均不会显著改变乳腺癌幸存者或对照组的生殖激素浓度。
