肠癌大鼠与正常大鼠粪便菌群的结构性差异

Compositional differences in fecal microbiota between rats with colorectal cancer and normal rats

目的:研究结肠癌大鼠与正常大鼠粪便菌群结构性变化.方法:通过1,2-二甲肼(dimethyl hydrazine,DMH)腹腔注射构建大肠癌的动物模型,造模成功后收集实验组和对照组大鼠肠道粪便,利用PCR-DGGE(polymerase chain reactiondenaturing gradient electrophoresis)技术分离菌群,对两组菌群相似性(聚类分析)和多态性(丰富度、均一性、Shannon-Wiener指数、Simpson指数)进行分析,并对目的菌群与GenBank进行比对,确定菌群种属,研究其变化规律.结果:相较于对照组,实验组中毛螺菌科(Lachnospiraceae)、Ruminococcaceae科菌、肠乳杆菌(Lactobacillus intestinalis)、帕拉普氏菌属(Paraprevotella)、鼠乳杆菌(Lactobacillus murinus)、乳杆菌属(Lactobacillus)、普氏菌属(Prevotella)、卷曲乳杆菌(Lactobacillus crispatus)和Lachnospiracea incertae sedis等菌群丰度显著降低,而粪芽孢菌属(Coprobacillus)丰度则明显增加.尽管两组菌群多样性均较丰富,但菌群结构相似性存在明显差异.结论:肠癌大鼠与正常对照组相比出现粪便菌群结构的偏移,有益菌减少,潜在致病菌增加.

AIM： To investigate the compositional differences in fecal flora between rats with colorectal cancer and normal rats. METHODS： A rat model of colorectal cancer was developed by intraperitoneal injection of 1, 2-dimethyl hydrazine （DMH）. Fecal samples were collected from rats with colorectal cancer and normal controls, and the microbiota was isolated by PCR-DGGE technique to perform flora similarity analysis （cluster analysis） and polymorphism analysis （richness, uniformity,Shannon-Wiener index, Simpson index） and to compare with the GenBank to identify the genus so as to study the variation. RESULTS： Compared with normal rats, the abundance of Lachnospiraceae, Ruminococcaceae, Lactobacillus intestinalis, Paraprevotella, Lactobacillus murinus, Lactobacillus, Prevotella, Lactobacillus crispatus and Lachnospiracea incertae sedis was significantly reduced and that of Coprobacillus was significantly increased in rats with colorectal cancer. Although the flora diversity between the two groups showed no statistical difference, there was a significant difference in flora composition. CONCLUSION： The composition of fecal mi- croflora changes in rats with colorectal cancer compared with normal rats, with the number of beneficial bacteria reduced and that of potential pathogens increased.