Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China.
Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, Chengdu, Sichuan, P. R. China.
Mol Nutr Food Res. 2017 Oct;61(10). doi: 10.1002/mnfr.201700012. Epub 2017 Jul 18.
Dietary fibers, consisting of nonstarch polysaccharides (NSPs) were found to modulate the gut microbiota. However, little is known about the role of a separated fiber fraction. Here, we describe a response in gut microbiome to different fiber fractions using a porcine model.
Ileal and cecal digesta were collected from pigs fed with fiber-free diet (FFD) or diet containing 5% cellulose (CEL), xylan (XYL) or β-glucan (GLU). We observed an elevated 16S rRNA gene copies in ileum and cecum digesta after NSP ingestion. Interestingly, we found that cecum digesta contained higher bacterial diversity than ileum digesta. Moreover, NSPs had no significant influence on overall diversity, but acutely altered the abundance of specific bacteria. Importantly, NSPs decreased the abundance of phylum Firmicutes, but increased the phylum Proteobacteria in ileal samples. Among the NSP-treated groups, pigs on CEL-containing diet had exclusively higher abundance of Lactobacillus spp. in the ileum. Whereas, the GLU-treated samples had more Clostridium spp.
This study not only indicated how the gut microbiome adapts to the three major NSP fractions, but the results also contribute to our understanding of the role of dietary fibers in modulating gut microbiota and health.
膳食纤维由非淀粉多糖（NSPs）组成，被发现可调节肠道微生物群。然而，对于分离的纤维部分的作用知之甚少。在这里，我们使用猪模型描述了肠道微生物组对不同纤维部分的反应。
从用无纤维饮食（FFD）或含有 5%纤维素（CEL）、木聚糖（XYL）或β-葡聚糖（GLU）的饮食喂养的猪中收集回肠和盲肠内容物。我们观察到 NSP 摄入后回肠和盲肠内容物中的 16S rRNA 基因拷贝数升高。有趣的是，我们发现盲肠内容物比回肠内容物含有更高的细菌多样性。此外，NSP 对总体多样性没有显著影响，但急性改变了特定细菌的丰度。重要的是，NSP 降低了厚壁菌门的丰度，但增加了回肠样品中的变形菌门。在 NSP 处理组中，CEL 饮食组的猪回肠中乳杆菌属的丰度明显更高。相比之下，GLU 处理组的样品中梭菌属的丰度更高。
本研究不仅表明了肠道微生物组如何适应三种主要 NSP 部分，而且研究结果也有助于我们理解膳食纤维在调节肠道微生物群和健康方面的作用。
