The gut microbial diversity of colon cancer patients and the clinical significance

The microbial diversity and communities in the excrement of healthy and patients suffered from cancer were identified by 16SrDNA sequencing performed on the Illumina Hi Seq sequencing platform. The microbial difference was also analyzed. The sequencing results showed high quality of the data, and the microbial communities were more various in the excrement of cancer patients. And the abundance of Firmicutes phylum was significantly reduced in cancer group. The phylum of Fermicutes, Bacteroidetes in cancer group are significantly down-regulated and up-regulated compared with normal group. The species of <i>Faecalibacterium prausnitzii, Bateroides vulgatus</i> and <i>Fusicatenibacter saccharivorans</i> are significantly lower in cancer group than that in normal group (<i>P</i>&lt; 0.05). The species of <i>Prevetella copri, M. uniformis,</i> and <i>Escherichia coli</i> are significantly higher in the cancer group than that in normal group. The comparative results indicated that beneficial bacterium significantly decreased in colorectal cancer (CRC) group, and harmful bacterium significantly increased in the colon cancer group, meanwhile the acidity, sugar increased whereas the oxygen content decreased to facilitate the growth of harmful bacterium. The results would provide microbial approaches for the treatment of colon cancer by the intake of beneficial microbial communities.

本研究通过在Illumina HiSeq测序平台（Illumina HiSeq sequencing platform）上开展的16S rDNA测序（16S rDNA sequencing）技术，鉴定了健康人群与癌症患者粪便样本中的微生物多样性及群落组成，并分析了微生物群落差异。测序结果显示数据质量优异，癌症患者粪便中的微生物群落多样性更为丰富。厚壁菌门（Firmicutes）在癌症组中的丰度显著降低；与正常对照组相比，癌症组的厚壁菌门丰度显著下调，拟杆菌门（Bacteroidetes）丰度显著上调。普拉梭菌（Faecalibacterium prausnitzii）、普通拟杆菌（Bacteroides vulgatus）及食糖产酸梭杆菌（Fusicatenibacter saccharivorans）的丰度在癌症组中显著低于正常组（P<0.05）；而普雷沃菌（Prevotella copri）、M. uniformis及大肠杆菌（Escherichia coli）的丰度则显著高于正常组。对比分析结果表明，结直肠癌（colorectal cancer, CRC）组内有益菌丰度显著降低，结肠癌组内有害菌丰度显著升高；同时肠道内酸度与糖分含量上升，氧含量下降，为有害菌的增殖提供了有利条件。本研究结果可为通过摄入有益微生物群落治疗结肠癌提供微生物学干预途径。