PDF(Pubmed)
Abstract：
The human gut microbiome is currently recognized to play a vital role in human biology and development, with diet as a major modulator. Therefore, novel indigestible polysaccharides that confer a health benefit upon their fermentation by the microbiome are under investigation. Based on the recently demonstrated prebiotic potential of a carrot-derived pectin extract enriched for rhamnogalacturonan I (cRG-I), the current study aimed to assess the impact of cRG-I upon repeated administration using the M-SHIME technology (3 weeks at 3g cRG-I/d). Consistent effects across four simulated adult donors included enhanced levels of acetate (+21.1 mM), propionate (+17.6 mM), and to a lesser extent butyrate (+4.1 mM), coinciding with a marked increase of OTUs related to Bacteroides dorei and Prevotella species with versatile enzymatic potential likely allowing them to serve as primary degraders of cRG-I. These Bacteroidetes members are able to produce succinate, explaining the consistent increase of an OTU related to the succinate-converting Phascolarctobacterium faecium (+0.47 log10(cells/mL)). While the Bifidobacteriaceae family remained unaffected, a specific OTU related to Bifidobacterium longum increased significantly upon cRG-I treatment (+1.32 log10(cells/mL)). Additional monoculture experiments suggested that Bifidobacterium species are unable to ferment cRG-I structures as such and that B. longum probably feeds on arabinan and galactan side chains of cRG-I, released by aforementioned Bacteroidetes members. Overall, this study confirms the prebiotic potential of cRG-I and additionally highlights the marked consistency of the microbial changes observed across simulated subjects, suggesting the involvement of a specialized consortium in cRG-I fermentation by the human gut microbiome.
摘要：
人类肠道微生物组目前被认为在人类生物学和发育中起着至关重要的作用。以饮食为主要调节剂。因此,正在研究通过微生物组发酵的新型难消化多糖对健康有益。基于最近证明的富含鼠李糖半乳糖醛酸I（cRG-I）的胡萝卜衍生果胶提取物的益生元潜力，本研究旨在评估cRG-I在使用M-SHIME技术重复给药(3周,3gcRG-I/d)时的影响.四个模拟成人供体的一致效果包括增加乙酸盐水平（+21.1mM），丙酸盐（+17.6mM），和较小程度的丁酸盐（+4.1mM），与多氏拟杆菌和普雷沃氏菌物种相关的OTU的显着增加同时，具有多种酶促潜力，可能使它们成为cRG-I的主要降解剂。这些拟杆菌成员能够产生琥珀酸，解释了与琥珀酸转化型屎相分枝杆菌相关的OTU的持续增加(+0.47log10(细胞/mL))。虽然双歧杆菌科没有受到影响，cRG-I治疗后,与长双歧杆菌相关的特定OTU显著增加(+1.32log10(细胞/mL)).其他单一培养实验表明，双歧杆菌无法发酵cRG-I结构，而长双歧杆菌可能以cRG-I的阿拉伯聚糖和半乳聚糖侧链为食，由上述拟杆菌成员释放。总的来说,这项研究证实了cRG-I的益生元潜力，并强调了在模拟受试者中观察到的微生物变化的显着一致性，这表明一个专门的财团参与了人类肠道微生物组的cRG-I发酵。
