Laboratory of Applied Microbiology, Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9 Nishi 9, Kita-ku, Sapporo 060-8589, Japan.
Department of Agronomy, Purdue University, West Lafayette, Indiana 47907-2054, USA.
Biosci Microbiota Food Health. 2013;32(4):167-78. doi: 10.12938/bmfh.32.167. Epub 2013 Oct 30.
The yacon (Smallanthus sonchifolius) tuber was examined with regard to its prebiotic effects compared with commercialized fructo-oligosaccharides (FOS). A feed containing 10% yacon tuber, which is equivalent to 5% commercialized FOS in terms of the amount of fructo-oligosaccharides (GF2, GF3 and GF4), was administrated to rats for 28 days. The yacon diet changed the intestinal microbial communities beginning in the first week, resulting in a twofold greater concentration of cecal short-chain fatty acids (SCFAs). The SCFA composition differed, but the cecal pH in rats fed yacon tuber was equal to that in rats fed FOS. Serum triglycerides were lower in rats fed yacon compared with rats fed FOS and the control diet. Cecal size was greater with the yacon tuber diet compared with the control diet. The abundant fermentation in the intestines created a selective environment for the intestinal microbiota, which included Lactobacillus acidophilus, Bifidobacterium pseudolongum, Bifidobacterium animalis and Barnesiella spp. according to identification with culture-independent analysis, 16S rRNA gene PCR-DGGE combined with cloning and sequencing. Barnesiella spp. and B. pseudolongum were only found in the rats fed the yacon diet, while L. acidophilus and B. animalis were found in abundance in rats fed both the yacon and FOS diets. The genus Barnesiella has not previously been reported to be associated with yacon or FOS fermentation. We concluded that the physiological and microbiological effects of the yacon tuber were different from those of FOS. Differences in cecal size, blood triglycerides and microbial community profiles including their metabolites (SCFAs) between the yacon tuber and FOS were shown to be more greatly affected by the yacon tuber rather than FOS.
雪莲果块根与商业化低聚果糖（FOS）的益生元作用进行了比较研究。用含有 10%雪莲果块根的饲料（相当于 5%商业化 FOS 的低聚果糖含量，GF2、GF3 和 GF4）对大鼠进行 28 天喂养。雪莲果饮食从第一周开始改变肠道微生物群落，导致盲肠短链脂肪酸（SCFA）浓度增加一倍。SCFA 组成不同，但雪莲果喂养组大鼠的盲肠 pH 值与 FOS 喂养组大鼠相同。与 FOS 喂养组和对照组相比，雪莲果喂养组大鼠的血清甘油三酯水平较低。与对照组相比，雪莲果块根饮食组大鼠的盲肠体积更大。肠道的大量发酵为肠道微生物群创造了一个选择性环境，根据非培养分析、16S rRNA 基因 PCR-DGGE 结合克隆和测序鉴定，包括嗜酸乳杆菌、假长双歧杆菌、动物双歧杆菌和 Barnesiella 属。Barnesiella 属和假长双歧杆菌仅在雪莲果饮食组大鼠中发现，而嗜酸乳杆菌和动物双歧杆菌在雪莲果和 FOS 饮食组大鼠中均大量存在。Barnesiella 属以前没有报道与雪莲果或 FOS 发酵有关。我们得出结论，雪莲果块根的生理和微生物作用与 FOS 不同。与 FOS 相比，雪莲果块根和 FOS 对盲肠大小、血液甘油三酯和微生物群落谱及其代谢物（SCFA）的影响更大。
