肠道内菌群结构与大肠肿瘤的相关性

Relationship of Microbial Community Structure in Intestine with Colorectal Cancer

目的:研究肠道内菌群结构与大肠肿瘤的相关性。方法:选取2014年1月—2015年6月年收治的大肠癌患者31例、大肠腺瘤患者31例及同期健康体检者(对照组)31例,收集3组粪便标本,提取粪便DNA,采用荧光定量PCR对DNA指纹图谱进行测序,比较3组肠道菌群结构的差异。结果:3组样本共获得254 271条高质量序列,3组细菌多样性指数比较差异无统计学意义(P>0.05)。对照组拟杆菌属、罗氏菌属、酸杆菌属、真杆菌属、变形菌属所占比例分别为21.00%,4.10%,2.14%,0.61%,0.49%高于大肠癌组的14.00%,1.56%,0.79%,0.11%,0.12%和大肠腺瘤组的16.03%,1.62%,0.82%,0.12%,0.14%。大肠癌组紫单胞菌属、埃希杆菌、肠球菌属、链球菌属、消化链球菌属所占比例分别为1.75%,2.45%,2.34%,1.19%,0.71%;大肠腺瘤组分别为1.62%,2.32%,2.12%,1.09%,0.69%,均高于对照组的0.09%,0.87%,0.10%,0.45%,0.01%。大肠癌组拟杆菌属、罗氏菌属所占比例低于大肠腺瘤组,肠球菌属、链球菌属所占比例高于大肠腺瘤组荧光定量PCR检测显示对照组拟杆菌占总菌相对含量、丁酸盐产生菌占总菌相对含量为(17.38±3.04)%、(4.38±1.03)%分别高于大肠癌组的(10.85±2.54)%、(1.41±0.89)%与大肠腺瘤组的(12.37±2.05)%、(2.07±1.02)%,大肠癌组含量则少于大肠腺瘤组(P<0.05)。结论:人体肠道内拟杆菌属、丁酸盐产生菌及链球菌等条件致病菌的结构失衡,与大肠肿瘤发生密切相关。

ObjectiveTo study the relationship of microbial community structure in the intestine withcolorectal cancer.MethodsStool specimens were collected in 31 patients with colorectal cancer and 31 pa-tients with colorectal adenoma and 31 cases of healthy volunteers from Janurary 2014 to June 2015.Fecal DNAwas extracted with fluorescence quantitative PCR for sequencing DNA fingerprinting to compare differences ingut microflora among the three groups.ResultsTotally 254 271 high quality arrays were obtained from the 3specimen groups,and no statistical differences were found among the 3 groups of multiple polyindices（P〈0.05）.Proportions of bacteroides genus,Roche genus,acid bacillus,bacillus genera and deformation bacteria in controlgroup were respectively 21.00%,4.10%,2.14%,0.61% and 0.49%,higher than those in colorectal cancer group（14.00%,1.56%,0.79%,0.11%,0.12% and 16.03%）and in coloretal adenomas group（16.03%,1.62%,0.82%,0.12%,0.14%）.Proportions of purple aneromonas spp,escherichia coli,enterococcus,streptococcus and pepto-streptococcus in colorectal cancer group were 1.75%,2.45%,2.34%,1.19% and 0.17% respectively.But forcolorectal adenomas group,proportions of these bacteria were 1.62%,2.32%,2.12%,1.09% and 0.69%,respec-tively.Proportions of these bacteria in above two group were higher than those in control group（they were0.09%,0.87%,0.10%,0.45% and 0.01%,respectively）.Proportions of bacteroides and Roche genus in colorectalgroup were lower than those in colorectal adenomas group,but for proportions of enterococcus and streptococcus,higher than those in colorectal group.Fluorescence quantitative PCR detection showed that bacteroides relativecontent and butyric acid salt producing bacteria relative content in control group were（17.38 ± 3.04）% and（4.38±1.03）%,higher than those in colorectal cancer group [（10.85±2.54）%,（1.41±0.89）%] and colorectal ade-nomas group [（12.37±2.05）%,（2.07±1.02）%].ConclusionStructural imbalance of gut bacteroides,butyr-ate-producing bacteria and opportunistic pathogens Streptococcus is closely related to the occurrence of colorec-tal cancer.