Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan,
Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Digestion. 2022;103(4):308-318. doi: 10.1159/000524023. Epub 2022 Apr 8.
An association has been found between human-gut microbiota and various diseases (e.g., metabolic disease) by analyzing fecal or colonic microbiota. Despite the importance of the small intestinal microbiota, sampling difficulties prevent its full analysis. We investigated the composition and metagenomic functions of microbiota along the small intestine and compared them with the microbiota from feces and from other gastrointestinal (GI) sites.
Mucosal samples from the six GI sites (stomach, duodenum, distal jejunum, proximal ileum, terminal ileum, and rectum) were collected under balloon-assisted enteroscopy. Fecal samples were collected from all participants. The microbial structures and metagenomic functions of the small intestinal mucosal microbiota were compared with those from feces and other GI sites using 16S ribosomal RNA gene sequencing.
We analyzed 133 samples from 29 participants. Microbial beta diversity analysis showed that the jejunum and ileum differed significantly from the lower GI tract and the feces (p < 0.001). Jejunal and duodenal microbiotas formed similar clusters. Wide clusters spanning the upper and lower GI tracts were observed with the ileal microbiota, which differed significantly from the jejunal microbiota (p < 0.001). Veillonella and Streptococcus were abundant in the jejunum but less so in the lower GI tract and feces. The metagenomic functions associated with nutrient metabolism differed significantly between the small intestine and the feces.
The fact that the compositional structures of small intestinal microbiota differed from those of fecal and other GI microbiotas reveals that analyzing the small intestinal microbiota is necessary for association studies on metabolic diseases and gut microbiota.
通过分析粪便或结肠微生物群，发现人类肠道微生物群与各种疾病（例如代谢疾病）之间存在关联。尽管小肠微生物群很重要，但采样困难阻止了对其进行全面分析。我们研究了小肠内微生物群的组成和宏基因组功能，并将其与粪便和其他胃肠道（GI）部位的微生物群进行了比较。
通过气囊辅助式内镜收集六个 GI 部位（胃、十二指肠、远端空肠、近端回肠、回肠末端和直肠）的黏膜样本。从所有参与者中收集粪便样本。使用 16S 核糖体 RNA 基因测序比较小肠黏膜微生物群的微生物结构和宏基因组功能与粪便和其他 GI 部位的微生物群。
我们分析了 29 名参与者的 133 个样本。微生物β多样性分析表明，空肠和回肠与下消化道和粪便有显著差异（p<0.001）。空肠和十二指肠的微生物群形成相似的聚类。观察到回肠微生物群具有广泛的聚类，跨越上消化道和下消化道，与空肠微生物群有显著差异（p<0.001）。韦荣球菌和链球菌在空肠中丰富，但在下消化道和粪便中较少。与营养代谢相关的宏基因组功能在小肠和粪便之间有显著差异。
小肠微生物群的组成结构与粪便和其他 GI 微生物群的组成结构不同，这表明分析小肠微生物群对于代谢疾病和肠道微生物群的关联研究是必要的。
