微生物转化影响不同内源雌激素水平大鼠粪便雌马酚含量和菌群结构

Microbial conversion of daidzein affects fecal equol concentration and bacterial composition of rats with or without ovariectomy

雌马酚(Equol)是肠道中特定细菌转化大豆异黄酮的产物,与其前体大豆苷元(Daidzein)相比,雌马酚具有更强的生物学活性。【目的】研究口服雌马酚产生菌对大鼠转化大豆苷元能力的可能促进作用及内源雌激素对大鼠肠道菌群的可能影响。【方法】使用平均体重为211±9g的卵巢摘除和假手术雌性大鼠各30只,分别随机分为5组,并灌胃蒸馏水、雌二醇、大豆苷元、雌马酚和大豆苷元+雌马酚产生菌ZX7。【结果】从灌胃第2天开始,接受大豆苷元后大鼠粪样中始终具有较高水平的雌马酚,显著高于对照和雌二醇组(P<0.01);灌胃大豆苷元+雌马酚产生菌ZX7的大鼠和直接灌胃雌马酚的大鼠在粪样雌马酚含量上十分接近;DGGE图谱的PCA分析显示,卵巢摘除大鼠和假手术大鼠粪便菌群存在明显差异;大鼠粪便拟杆菌门细菌数量与粪样中雌马酚水平显著正相关。【结论】大鼠肠道固有菌群中可能存在能够将大豆苷元转化为雌马酚的细菌,利用外源菌株改变大鼠雌马酚产生能力具有一定的可行性,不同的内源雌激素水平可能影响大鼠肠道菌群结构,拟杆菌门细菌可能在大豆苷元的生物转化过程中起着十分重要的作用。

Equol is the end metabolite of daidzein by certain intestinal bacteria, which has stronger bioactivity comparing with daidzein. [ Objective] To evaluate the role of orally administrated equol-produeing bacterium on increasing equol production and shifting intestinal microbiota of embracer animal. [ Methods] In total 60 rats with or without ovariectomy at average bodyweight 211 ＋ 9g were divided into 5 groups. The differences on equol concentration and bacterial composition were compared in rats orally treated with distilled water, estradiol, daidzein, equol and daidzein ＋ ZX7. [ Results] The fecal equol concentration in daidzein groups was significantly higher than that in control and estradiol groups. The fecal equol concentration in daidzein ＋ ZX7 groups was comparable to that in equol groups. Principal Components Analysis （PCA） of fecal DGGE profiles showed clear difference of fecal microbiota between ovariectomy done or undone rats. Fecal population of Bacteriodetes showed strong correlation with fecal equol concentration. [ Conclusion] Normal intestinal microbiota in rats might have the capacity to convert daidzein into equol. Dietary source of equol- producing bacterium ZX7 might have the possibility to increase the equol production of embracer animal. Endogenous estrogen concentration might shift the intestinal microbiota on rats. Bacteriodetes might have an important role on equol production.