Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Department of Food Science and Engineering, Inner Mongolia Agricultural University, Huhhot, Inner Mongolia 010018, PR China.
Res Microbiol. 2012 Jun;163(5):357-65. doi: 10.1016/j.resmic.2012.04.002. Epub 2012 Apr 20.
Studies have found that the survival of probiotics could be strongly enhanced with dairy products as delivery vehicles, but the molecular mechanism by which this might occur has seldom been mentioned. In this study, microarray technology was used to detect the gene expression profile of Lactobacillus casei Zhang with and without fermented milk used as a delivery vehicle during transit in simulated gastrointestinal juice. Numerous genes of L. casei Zhang in strain suspension were upregulated compared to those from L. casei Zhang in fermented milk. These data might indicate that L. casei Zhang is stimulated directly without the protection of fermented milk, and the high-level gene expression observed here may be a stress response at the transcriptional level. A large proportion of genes involved in translation and cell division were downregulated in the bacteria that were in strain suspension during transit in simulated intestinal juice. This may impede protein biosynthesis and cell division and partially explain the lower viability of L. casei Zhang during transit in the gastrointestinal tract without the delivery vehicle.
研究发现，益生菌的存活率可以通过乳制品作为载体得到显著提高，但这种情况发生的分子机制却很少被提及。在这项研究中，我们使用微阵列技术来检测在模拟胃肠道消化液中运输时，有无发酵乳作为载体对干酪乳杆菌张的基因表达谱的影响。与发酵乳中的干酪乳杆菌张相比，悬浮在菌悬液中的干酪乳杆菌张的许多基因被上调。这些数据可能表明，干酪乳杆菌张在没有发酵乳保护的情况下受到了直接刺激，而这里观察到的高水平基因表达可能是转录水平的应激反应。在模拟肠液中运输时，悬浮在菌悬液中的细菌中参与翻译和细胞分裂的大量基因下调。这可能会阻碍蛋白质生物合成和细胞分裂，并部分解释了在没有载体的情况下，干酪乳杆菌张在胃肠道中的存活率较低的原因。
