Degradation of cross-linked and non-cross-linked arabinoxylans by the intestinal microbiota in children
Degradation of cross-linked and non-cross-linked arabinoxylans by the intestinal microbiota in children
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DOI：
10.1128/aem.69.11.6354-6360.2003
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发表时间：
2003-11-01
影响因子：
4.4
通讯作者：
McBain, AJ
中科院分区：
文献类型：
--
作者：
Hopkins, MJ;Englyst, HN;McBain, AJ
在人类中，非淀粉多糖（NSP），如阿拉伯聚糖（AX），在上消化道中不被消化，并为大肠中生长的细菌提供可发酵的碳源。尽管AX在自然界中普遍存在，但对AX在肠道中消化的微生物学和生理学后果知之甚少。在这项研究中，我们研究了阿魏酸交联AX（AXF）和非交联AX在儿童肠道微生物菌群中的分解，使用淀粉作为一种易于发酵的多糖进行比较。在厌氧条件下使用pH控制的发酵容器进行实验。结果表明，结肠微生物对这些多糖的代谢存在差异。AX总是比淀粉降解得更慢，而阿魏酸交联降低了AX发酵的速率，如发酵产物测量所示。淀粉消化与显着的乙酸盐和丁酸盐的生产，而AX分解导致丙酸盐的形成增加。一般而言，可发酵碳水化合物的存在显著增加了总厌氧菌计数和真细菌rRNA浓度（P < 0.01），而非交联AX消化主要与脆弱拟杆菌群生物体的活菌计数增加相关，这得到了拟杆菌-卟啉单胞菌-普雷沃氏菌群rRNA增加的支持（P < 0.01）。在这些发酵中，淀粉比AX的生物合成性高得多。总之，在这项研究中，我们发现AX和AXF对儿童和成人肠道微生物的微生物生态和代谢的影响是相似的。
In humans, nonstarch polysaccharides (NSP), such as arabinoxylans (AX), are not digested in the upper gut and provide fermentable carbon sources for bacteria growing in the large bowel. Despite the ubiquity of AX in nature, the microbiologic and physiologic consequences of AX digestion in the gut are poorly understood. In this study, we investigated the breakdown of ferulic acid-cross-linked AX (AXF) and non-cross-linked AX in children's intestinal microbiotas, using starch as a readily fermentable polysaccharide for comparative purposes. The experiments were performed using pH-controlled fermentation vessels under anaerobic conditions. The results demonstrated that there was variation in the metabolism of these polysaccharides by colonic microbiotas. AX was always degraded more slowly than starch, while ferulic acid cross-linking reduced the rate of AX fermentation, as shown by fermentation product measurements. Starch digestion was associated with significant acetate and butyrate production, whereas AX breakdown resulted in increased propionate formation. In general, the presence of fermentable carbohydrate significantly increased the total anaerobe counts and eubacterial rRNA concentrations (P < 0.01), while non-cross-linked AX digestion was principally associated with increased viable counts of Bacteroides fragilis group organisms, which was supported by increases in Bacteroides-Porphyromonas-Prevotella group rRNA (P < 0.01). Starch was considerably more bifidogenic than AX in these fermentations. In conclusion, in this study we found that the effects of AX and AXF on the microbial ecology and metabolism of intestinal microbiotas are similar in children and adults.