A new method for the in vitro determination of the bile tolerance of potentially probiotic lactobacilli
A new method for the in vitro determination of the bile tolerance of potentially probiotic lactobacilli
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DOI：
10.1007/s00253-018-8742-x
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发表时间：
2018-02-01
影响因子：
5
通讯作者：
Guo, Chun-Feng
中科院分区：
文献类型：
--
作者：
Hu, Peng-Li;Yuan, Ya-Hong;Guo, Chun-Feng
开发了一种新的体外方法来确定潜在益生菌乳酸杆菌的胆汁耐受性。将各种乳杆菌菌株的过夜培养物接种到添加或不添加0.3%（wt/vol）牛胆汁的无菌半强MRS肉汤中，用0.1M磷酸钠缓冲液缓冲至最终pH 7.3，并在厌氧条件下于37℃孵育12小时。乳杆菌菌株的胆汁耐受能力表示为牛胆汁存在下的细菌细胞的繁殖代数与牛胆汁不存在下的细菌细胞的繁殖代数的百分比。采用新开发的方法和两种传统方法分析了 8 种乳杆菌的 11 株菌株（包括 3 株胆盐水解酶（BSH）阴性菌株和 8 株 BSH 阳性菌株）的胆汁耐受能力。结果表明，根据所使用的分析方法，菌株的胆汁耐受能力有很大差异。新开发的方法模拟了人体小肠的生理环境，避免了潜伏期内pH值和胆汁盐成分的变化，这是传统胆汁耐受性测试方法的缺点。因此，本研究开发的分析方法更适合筛选或比较乳酸菌菌株的胆汁耐受能力。
A new in vitro method was developed to determine the bile tolerance of potentially probiotic lactobacilli. The overnight culture of various lactobacilli strains was inoculated into sterile, half-strength MRS broth supplemented with and without 0.3% (wt/vol) oxgall, buffered with 0.1 M sodium phosphate buffer at a final pH of 7.3, and incubated at 37 degrees C for 12 h under anaerobic conditions. The bile tolerance ability of the lactobacilli strains was expressed as the percentage of the propagation generations of the bacterial cells in the presence of oxgall to those in the absence of oxgall. The bile tolerance ability of 11 strains of 8 Lactobacillus species, including 3 bile salt hydrolase (BSH)-negative strains and 8 BSH-positive strains, was analyzed using the newly developed method and two traditional methods. The results showed that bile tolerance ability of the strains was considerably different depending on the analysis method used. The newly developed method mimics the physiological environment of the human small intestine, and avoids changes in pH and bile salt composition during the incubation period, which are drawbacks of the traditional bile tolerance test methods. Therefore, the analysis method developed in this study is more suitable to screen or compare the bile tolerance ability of lactobacilli strains.