Department of Food Science and Technology, University of Nebraska, Lincoln, NE 68583-0919, USA.
Int J Food Microbiol. 2010 Dec 15;144(2):285-92. doi: 10.1016/j.ijfoodmicro.2010.10.007. Epub 2010 Oct 14.
The goal of this research was to determine the effect of different doses of galactooligosaccharide (GOS) on the fecal microbiota of healthy adults, with a focus on bifidobacteria. The study was designed as a single-blinded study, with eighteen subjects consuming GOS-containing chocolate chews at four increasing dosage levels; 0, 2.5, 5.0, and 10.0g. Subjects consumed each dose for 3 weeks, with a two-week baseline period preceding the study and a two-week washout period at the end. Fecal samples were collected weekly and analyzed by cultural and molecular methods. Cultural methods were used for bifidobacteria, Bacteroides, enterobacteria, enterococci, lactobacilli, and total anaerobes; culture-independent methods included denaturing gradient gel electrophoresis (DGGE) and quantitative real-time PCR (qRT-PCR) using Bifidobacterium-specific primers. All three methods revealed an increase in bifidobacteria populations, as the GOS dosage increased to 5 or 10g. Enumeration of bifidobacteria by qRT-PCR showed a high inter-subject variation in bifidogenic effect and indicated a subset of 9 GOS responders among the eighteen subjects. There were no differences, however, in the initial levels of bifidobacteria between the responding individuals and the non-responding individuals. Collectively, this study showed that a high purity GOS, administered in a confection product at doses of 5g or higher, was bifidogenic, while a dose of 2.5g showed no significant effect. However, the results also showed that even when GOS was administered for many weeks and at high doses, there were still some individuals for which a bifidogenic response did not occur.
本研究旨在确定不同剂量半乳糖寡糖（GOS）对健康成年人粪便微生物群的影响，重点关注双歧杆菌。该研究设计为单盲研究，18 名受试者分别摄入四种递增剂量（0、2.5、5.0 和 10.0g）的含 GOS 的巧克力咀嚼片。受试者每种剂量服用 3 周，在研究前有两周的基线期和研究结束时两周的洗脱期。每周收集粪便样本并通过培养和分子方法进行分析。培养方法用于双歧杆菌、拟杆菌、肠杆菌、肠球菌、乳杆菌和总厌氧菌；非培养方法包括变性梯度凝胶电泳（DGGE）和使用双歧杆菌特异性引物的定量实时 PCR（qRT-PCR）。所有三种方法都显示出双歧杆菌种群的增加，随着 GOS 剂量增加到 5 或 10g。qRT-PCR 计数双歧杆菌显示出双歧生成效应的高个体间变异性，并表明在 18 名受试者中有 9 名 GOS 应答者亚组。然而，在应答个体和非应答个体之间，双歧杆菌的初始水平没有差异。总之，这项研究表明，高纯度 GOS，以糖果产品的形式在 5g 或更高剂量下给药，具有双歧生成作用，而 2.5g 的剂量没有显示出显著效果。然而，结果还表明，即使 GOS 被给予数周和高剂量，仍有一些个体没有出现双歧生成反应。
