PDF(Pubmed)
Abstract：
Isomalto/malto-polysaccharides (IMMPs) are a novel type of soluble dietary fibres with a prebiotic potential promoting growth of beneficial microbes in the gut. However, the mode of action of IMMPs remains unknown. Previous studies on IMMPs showed an increase in total bacteria, especially lactobacilli, and higher production of short chain fatty acids (SCFA) when IMMPs were fed to rats or used during in vitro fermentation. Here we used metatranscriptomics to investigate how IMMPs with different amounts of α - (1 → 6) glycosidic linkages affected microbial function during incubation with human fecal inoculum. We showed that active microbial community dynamics during fermentation varied depending on the type of IMMP used and that the observed changes were reflected in the community gene expression profiles. Based on metatranscriptome analysis, members of Bacteroides, Lactobacillus and Bifidobacterium were the predominant degraders of IMMPs, and the increased gene expression in these bacteria correlated with high amounts of α - (1 → 6) glycosidic linkages. We also noted an increase in relative abundance of these bacteria and an activation of pathways involved in SCFA synthesis. Our findings could provide a baseline for more targeted approaches in designing prebiotics for specific bacteria and to achieve more controlled modulation of microbial activity towards desired health outcomes.
摘要：
异麦芽酮/麦芽多糖（IMMPs）是一种新型的可溶性膳食纤维，具有促进肠道有益微生物生长的益生元潜力。然而,IMMP的行动模式仍然未知。先前对IMMP的研究表明细菌总数增加，尤其是乳酸杆菌,当将IMMPs喂给大鼠或在体外发酵过程中使用时，短链脂肪酸（SCFA）的产量更高。在这里，我们使用metatracscriptomics来研究具有不同量的α-（1→6）糖苷键的IMMP在与人粪便接种物孵育期间如何影响微生物功能。我们表明，发酵过程中活跃的微生物群落动态取决于所使用的IMMP类型，并且观察到的变化反映在群落基因表达谱中。基于metatrandscriptome分析，拟杆菌的成员，乳杆菌和双歧杆菌是IMMPs的主要降解剂，这些细菌中基因表达的增加与大量的α-（1→6）糖苷键相关。我们还注意到这些细菌的相对丰度增加以及SCFA合成中涉及的途径的激活。我们的发现可以为设计特定细菌的益生元的更有针对性的方法提供基线，并实现对期望的健康结果的微生物活性的更受控的调节。
