Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China.
South Sichuan Institute of Translational Medicine, Luzhou, China.
Front Cell Infect Microbiol. 2021 Feb 26;11:599734. doi: 10.3389/fcimb.2021.599734. eCollection 2021.
Several reports suggesting that the intestinal microbiome plays a key role in the development of inflammatory bowel disease (IBD) or colorectal cancer (CRC), but the changes of intestinal bacteria in healthy people, patients with IBD and CRC are not fully explained. The study aimed to investigate changes of intestinal bacteria in healthy subjects, patients with IBD, and patients with CRC.
We collected data from the European Nucleotide Archive on healthy people and patients with colorectal cancer with the study accession number PRJEB6070, PRJEB7774, PRJEB27928, PRJEB12449, and PRJEB10878, collected IBD patient data from the Integrated Human Microbiome Project from the Human Microbiome Project Data Portal. We performed metagenome-wide association studies on the fecal samples from 290 healthy subjects, 512 IBD patients, and 285 CRC patients. We used the metagenomics dataset to study bacterial community structure, relative abundance, functional prediction, differentially abundant bacteria, and co-occurrence networks.
The bacterial community structure in both IBD and CRC was significantly different from healthy subjects. Our results showed that IBD patients had low intestinal bacterial diversity and CRC patients had high intestinal bacterial diversity compared to healthy subjects. At the phylum level, the relative abundance of Firmicutes in IBD decreased significantly, while the relative abundance of Bacteroidetes increased significantly. At the genus level, the relative abundance of in IBD was higher than in healthy people and CRC. Compared with healthy people and CRC, the main difference of intestinal bacteria in IBD patients was Bacteroidetes, and compared with healthy people and IBD, the main difference of intestinal bacteria in CRC patients was in Fusobacteria, Verrucomicrobia, and Proteobacteria. The main differences in the functional composition of intestinal bacteria in healthy people, IBD and CRC patients were L-homoserine and L-methionine biosynthesis, 5-aminoimidazole ribonucleotide biosynthesis II, L-methionine biosynthesis I, and superpathway of L-lysine, L-threonine, and L-methionine biosynthesis I. The results of stratified showed that the abundance of Firmicutes, Bacteroidetes, and Actinobacteria involved in metabolic pathways has significantly changed. Besides, the association network of intestinal bacteria in healthy people, IBD, and CRC patients has also changed.
In conclusion, compared with healthy people, the taxonomic and functional composition of intestinal bacteria in IBD and CRC patients was significantly changed.
有几项报告表明，肠道微生物群在炎症性肠病（IBD）或结直肠癌（CRC）的发展中起着关键作用，但健康人群、IBD 患者和 CRC 患者的肠道细菌变化尚不完全清楚。本研究旨在研究健康受试者、IBD 患者和 CRC 患者的肠道细菌变化。
我们从欧洲核苷酸档案中收集了健康人群和结直肠癌患者的数据，研究注册号为 PRJEB6070、PRJEB7774、PRJEB27928、PRJEB12449 和 PRJEB10878，从人类微生物组计划数据门户的综合人类微生物组计划中收集了 IBD 患者的数据。我们对 290 名健康受试者、512 名 IBD 患者和 285 名 CRC 患者的粪便样本进行了宏基因组关联研究。我们使用宏基因组数据集研究了细菌群落结构、相对丰度、功能预测、差异丰度细菌和共现网络。
IBD 和 CRC 的细菌群落结构与健康受试者明显不同。我们的结果表明，与健康受试者相比，IBD 患者的肠道细菌多样性较低，CRC 患者的肠道细菌多样性较高。在门水平上，IBD 中厚壁菌门的相对丰度显著降低，而拟杆菌门的相对丰度显著增加。在属水平上，IBD 中梭菌属的相对丰度高于健康人和 CRC。与健康人和 CRC 相比，IBD 患者肠道细菌的主要差异是拟杆菌门，与健康人和 IBD 相比，CRC 患者肠道细菌的主要差异是梭杆菌门、疣微菌门和变形菌门。健康人群、IBD 和 CRC 患者肠道细菌功能组成的主要差异是 L-同型半胱氨酸和 L-蛋氨酸生物合成、5-氨基咪唑核糖核苷酸生物合成 II、L-蛋氨酸生物合成 I 和 L-赖氨酸、L-苏氨酸和 L-蛋氨酸生物合成 I 的超级途径。分层结果表明，代谢途径中厚壁菌门、拟杆菌门和放线菌门的丰度发生了显著变化。此外，健康人群、IBD 和 CRC 患者肠道细菌的关联网络也发生了变化。
总之，与健康人群相比，IBD 和 CRC 患者的肠道细菌分类和功能组成发生了显著变化。
