He J D, Kong C, Gao R Y, Yin F, Zhang Y, Qin H L
Department of General Surgery, the Tenth People's Hospital, Tongji University, Shanghai 200072, China; Research Institute of Intestinal Diseases, Tongji University School of Medicine, Shanghai 200072, China.
Research Institute of Intestinal Diseases, Tongji University School of Medicine, Shanghai 200072, China; Department of Difficult Diagnosis and Treatment Center of Abdominal Surgery, The Tenth People's Hospital, Tongji University, Shanghai 200072, China.
Zhonghua Wei Chang Wai Ke Za Zhi. 2020 Jul 10;23(Z1):77-85. doi: 10.3760/cma.j.cn.441530-20200417-00223.
To establish the mice colorectal cancer (CRC) model induced by AOM/DSS with the intervention of high fat diet and probiotics, and to explore the potential mechanism of probiotics intervention in regulating intestinal flora disturbance and antitumor efficiency. Forty 8-week-old male C57BL/6J mice were randomly divided into 4 groups with 10 mice in each group: HFD group, HDF with probiotics intervention (HFD+P) group, normal diet (ND) group, normal diet with probiotics intervention (ND+P) group. The probiotic groups were administered with probiotics preparation by gavage. During the experiment, AOM/DSS was used to induce mouse colorectal cancer model. The mouse body weight was regularly recorded and the body status was evaluated weekly. High-throughput 16S rDNA sequencing was used to analyze the changes of fecal flora in bacterial structure before and after cancer induction. At the end of the experiment, intestinal tissues of mice were collected and the epididymis adipose mass (EAM) and tumor burden were recorded. The Alpha diversity index was used to analyze the abundance and diversity of the intestinal flora (higher chaol index means higher abundance of bacteria and greater Simpson index means lower diversity in flora structure). The Beta diversity index was used to analyze the significance of the difference in the distribution of intestinal flora among the four groups (When R>0, the difference in the distribution of bacteria among the groups is greater than the difference within the group). After 15 weeks of experiment, the body weight of mice in HFD group, HFD+P group, ND group and ND+P group was (33.70±0.52) g, (28.70±0.32) g, (25.90±0.34) g and (25.60±0.40) g, whose difference was statistically significant (=700.89, <0.01). The body weight of HFD group was higher than that of ND group and HFD+P group while the body weight of HFD+P group was still higher than that of ND group, and the differences were statistically significant (all <0.017). The average EAM of HFD group, HFD+P group, ND group and ND+P group was (1.36±0.15) g, (0.67±0.08) g, (0.58±0.10) g and (0.54±0.05) g, whose difference was statistically significant (=114.03, <0.01). Pairwise comparisons showed that EAM in HFD group was higher than that in ND group and HFD+P group respectively, with statistically significant difference (both <0.01), while average EAM of HFD+P group was similar to ND group (=0.09). Under the diet intervention, the Chao1 index of HFD group, HFD+P group, ND group and ND+P group was 217.62, 235.32, 301.51 and 305.71 respectively, and the Simpson index was 0.93, 0.89, 0.91 and 0.90. At the same time, the Anosim analysis of Beta diversity analysis showed that the difference in the flora distribution among four groups was greater than the difference with in each group with statistically significant difference (=0.655, =0.001). Species abundance analysis revealed that, compared with ND group, at phylum level, HFD group had a higher proportion of Bacteroides phylum and Firmicutes phylum in the intestinal flora and lower proportion of Verrucomicrobia; at genus level, the proportion of Bacteroides and Oscillibacter in HFD group was higher while the proportion of Akkermansia and Alloprevotella was lower. After the intervention of probiotics, the flora mentioned above was improved significantly except for Alloprevotella. The average number of tumor in HFD group, HFD+P group, ND group and ND+P group was 4.63±1.19, 2.33±0.52, 2.56±0.73 and 2.38±0.52 with statistically significant difference (=14.92, <0.01). Probiotics therapy can reduce obesity and flora imbalance caused by HFD and reduce the incidence of CRC by regulating intestinal flora disturbance.
建立高脂饮食和益生菌干预下AOM/DSS诱导的小鼠结直肠癌（CRC）模型，探讨益生菌干预调节肠道菌群紊乱及抗肿瘤效果的潜在机制。将40只8周龄雄性C57BL/6J小鼠随机分为4组，每组10只：高脂饮食（HFD）组、高脂饮食加益生菌干预（HFD+P）组、正常饮食（ND）组、正常饮食加益生菌干预（ND+P）组。益生菌组通过灌胃给予益生菌制剂。实验期间，用AOM/DSS诱导小鼠结直肠癌模型。定期记录小鼠体重，每周评估身体状况。采用高通量16S rDNA测序分析致癌前后粪便菌群细菌结构的变化。实验结束时，收集小鼠肠道组织，记录附睾脂肪量（EAM）和肿瘤负荷。用Alpha多样性指数分析肠道菌群的丰度和多样性（Chao1指数越高意味着细菌丰度越高，Simpson指数越大意味着菌群结构多样性越低）。用Beta多样性指数分析四组间肠道菌群分布差异的显著性（当R>0时，组间细菌分布差异大于组内差异）。实验15周后，HFD组、HFD+P组、ND组和ND+P组小鼠体重分别为（33.70±0.52）g、（28.70±0.32）g、（25.90±0.34）g和（25.60±0.40）g，差异有统计学意义（=700.89，<0.01）。HFD组体重高于ND组和HFD+P组，HFD+P组体重仍高于ND组，差异有统计学意义（均<0.017）。HFD组、HFD+P组、ND组和ND+P组的平均EAM分别为（1.36±0.15）g、（0.67±0.08）g、（0.58±0.10）g和（0.54±0.05）g，差异有统计学意义（=114.03，<0.01）。两两比较显示，HFD组EAM分别高于ND组和HFD+P组，差异有统计学意义（均<0.01），而HFD+P组平均EAM与ND组相似（=0.09）。饮食干预下，HFD组、HFD+P组、ND组和ND+P组Chao1指数分别为217.62、235.32、301.51和305.71，Simpson指数分别为0.93、0.89、0.91和0.90。同时，Beta多样性分析的Anosim分析显示，四组间菌群分布差异大于组内差异，差异有统计学意义（=0.655，=0.001）。物种丰度分析显示，与ND组相比，在门水平上，HFD组肠道菌群中拟杆菌门和厚壁菌门比例较高，疣微菌门比例较低；在属水平上，HFD组拟杆菌属和颤杆菌属比例较高，而阿克曼氏菌属和别普雷沃菌属比例较低。益生菌干预后，除别普雷沃菌属外，上述菌群均有明显改善。HFD组、HFD+P组、ND组和ND+P组平均肿瘤数分别为4.63±1.19、2.33±0.52、2.56±0.73和2.38±0.52，差异有统计学意义（=14.92，<0.01）。益生菌治疗可减轻高脂饮食引起的肥胖和菌群失衡，通过调节肠道菌群紊乱降低结直肠癌发病率。
