Modulation of the human gut microbiota by dietary fibres occurs at the species level.
Modulation of the human gut microbiota by dietary fibres occurs at the species level.
复制标题
通过饮食纤维对人肠道微生物群的调节发生在物种水平上。
DOI：
10.1186/s12915-015-0224-3
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发表时间：
2016-01-11
期刊：
影响因子：
5.4
通讯作者：
Flint HJ
中科院分区：
文献类型：
--
作者：
Chung WS;Walker AW;Louis P;Parkhill J;Vermeiren J;Bosscher D;Duncan SH;Flint HJ
膳食摄入特定的不可消化的碳水化合物（包括益生元）越来越被视为一种非常有效的方法，可以操纵人体肠道微生物群的组成和活动，从而有益于健康。然而，令人惊讶的是，我们对微生物群落对特定碳水化合物的全球反应知之甚少。最近的体内饮食研究表明，人类粪便微生物群的种类组成受到饮食摄入的影响。现在有可能通过使用产生高度控制的pH和底物供应条件的体外系统来深入了解所涉及的机制。我们在厌氧、ph控制的连续流发酵罐中为三种不同的人类肠道微生物群落提供了两种可选的不可消化多糖作为能量来源。群落分析表明，苹果果胶或菊粉的添加导致特定细菌操作分类单位（OTUs；基于16S rRNA基因序列）的高度特异性富集。在检测到的8个最丰富的拟杆菌OTUs中，2个由菊粉特异性促进，6个由果胶特异性促进。在厚壁菌门中，果胶对真杆菌有强烈的促进作用，而菊粉对一些物种有刺激作用。反应受到pH值的影响，在每个实验中，平行容器的pH值在5.5、6.0、6.4和6.9之间升高或降低。特别是，在pH降至5.5的实验中，观察到prausnitzii Faecalibacterium取代拟杆菌（Bacteroides）成为优势序列。以果胶为饲料的发酵罐比以菊粉为饲料的发酵罐的群落多样性更大，这可能反映了两种基质的不同复杂性。我们已经证明，特定的不可消化的膳食碳水化合物具有改变肠道微生物群的巨大潜力，但这些改变发生在单个菌株和物种的水平上，并且不容易先验地预测。此外，肠道环境，特别是pH值，在决定种间竞争的结果中起着关键作用。因此，我们必须付出更大的努力，确定一种特定的益生元方法可能刺激的细菌范围。出于有效性和安全性的考虑，旨在造福人类健康的益生元的开发必须考虑到可能产生的高度个性化的物种概况。本文的在线版本（doi:10.1186/s12915-015-0224-3）包含补充材料，可供授权用户使用。
Dietary intake of specific non-digestible carbohydrates (including prebiotics) is increasingly seen as a highly effective approach for manipulating the composition and activities of the human gut microbiota to benefit health. Nevertheless, surprisingly little is known about the global response of the microbial community to particular carbohydrates. Recent in vivo dietary studies have demonstrated that the species composition of the human faecal microbiota is influenced by dietary intake. There is now potential to gain insights into the mechanisms involved by using in vitro systems that produce highly controlled conditions of pH and substrate supply. We supplied two alternative non-digestible polysaccharides as energy sources to three different human gut microbial communities in anaerobic, pH-controlled continuous-flow fermentors. Community analysis showed that supply of apple pectin or inulin resulted in the highly specific enrichment of particular bacterial operational taxonomic units (OTUs; based on 16S rRNA gene sequences). Of the eight most abundant Bacteroides OTUs detected, two were promoted specifically by inulin and six by pectin. Among the Firmicutes, Eubacterium eligens in particular was strongly promoted by pectin, while several species were stimulated by inulin. Responses were influenced by pH, which was stepped up, and down, between 5.5, 6.0, 6.4 and 6.9 in parallel vessels within each experiment. In particular, several experiments involving downshifts to pH 5.5 resulted in Faecalibacterium prausnitzii replacing Bacteroides spp. as the dominant sequences observed. Community diversity was greater in the pectin-fed than in the inulin-fed fermentors, presumably reflecting the differing complexity of the two substrates. We have shown that particular non-digestible dietary carbohydrates have enormous potential for modifying the gut microbiota, but these modifications occur at the level of individual strains and species and are not easily predicted a priori. Furthermore, the gut environment, especially pH, plays a key role in determining the outcome of interspecies competition. This makes it crucial to put greater effort into identifying the range of bacteria that may be stimulated by a given prebiotic approach. Both for reasons of efficacy and of safety, the development of prebiotics intended to benefit human health has to take account of the highly individual species profiles that may result. The online version of this article (doi:10.1186/s12915-015-0224-3) contains supplementary material, which is available to authorized users.