Sugiyama Yukiko, Nagata Yoshie, Fukuta Fumimasa, Takayanagi Akio, Masumori Naoya, Tsukamoto Taiji, Akasaka Hiroshi, Ohnishi Hirofumi, Saito Shigeyuki, Miura Tetsuji, Moriyama Kaoru, Tsuji Hirokazu, Akaza Hideyuki, Mori Mitsuru
Department of Public Health, Sapporo Medical University School of Medicine, Sapporo, Japan E-mail :
Asian Pac J Cancer Prev. 2014;15(6):2693-7. doi: 10.7314/apjcp.2014.15.6.2693.
Isoflavones, which are included in soybeans, have been suggested to protect against prostate cancer. Equol, one of isoflavones, is an intestinally derived bacterial metabolite of daidzein. A newly identified equol-producing bacterium, Slackia sp. strain NATTS, with a high equol-producing activity was isolated from human feces in Japanese adults. Counts of Slackia sp. strain NATTS in intestinal flora have not been assessed with regard to prostate cancer risk. In this study, we investigated the association of serum isoflavones and counts of Slackia sp. strain NATTS with prostate cancer risk in a case-control study.
Concentrations of isoflavones and counts of Slackia sp. strain NATTS in feces were measured from 44 patients with prostate cancer and 28 hospital controls. The risk of prostate cancer was evaluated in terms of odds ratios (ORs) and 95% confidence intervals (CIs) by the logistic regression analysis.
The detection proportions of Slackia sp. strain NATTS in cases and controls were 34.1% and 25.0%, respectively. Counts of Slackia sp. strain NATTS were significantly correlated with serum concentrations of equol both in cases and controls (Spearman correlation coefficients, rs=0.639 and rs=0.572, p<0.01, respectively). Serum concentrations of genistein, daidzein, glycitein, and equol were not significantly associated with risk of prostate cancer.
This study found that counts of Slackia sp. strain NATTS correlated with serum concentrations of equol both in prostate cancer cases and controls, but serum isoflavone concentrations were not associated with risk of prostate cancer in our patients.
大豆中含有的异黄酮被认为具有预防前列腺癌的作用。雌马酚是异黄酮之一，是大豆苷元在肠道内由细菌代谢产生的产物。从日本成年人的粪便中分离出一种新发现的高产雌马酚的细菌——Slackia sp. 菌株NATTS。尚未评估肠道菌群中Slackia sp. 菌株NATTS的数量与前列腺癌风险之间的关系。在本病例对照研究中，我们调查了血清异黄酮和Slackia sp. 菌株NATTS数量与前列腺癌风险的关联。
测量了44例前列腺癌患者和28例医院对照者粪便中异黄酮的浓度以及Slackia sp. 菌株NATTS的数量。通过逻辑回归分析，根据比值比（OR）和95%置信区间（CI）评估前列腺癌风险。
病例组和对照组中Slackia sp. 菌株NATTS的检出比例分别为34.1%和25.0%。病例组和对照组中Slackia sp. 菌株NATTS的数量均与血清雌马酚浓度显著相关（斯皮尔曼相关系数，rs分别为0.639和0.572，p<0.01）。染料木黄酮、大豆苷元、黄豆黄素和雌马酚的血清浓度与前列腺癌风险无显著关联。
本研究发现，前列腺癌病例组和对照组中Slackia sp. 菌株NATTS的数量均与血清雌马酚浓度相关，但在我们的患者中，血清异黄酮浓度与前列腺癌风险无关。
