The Relationship Between Intestinal Flora Chnges And Colorectal Cancer After Cholecystectomy

Objective: Colorectal cancer(CRC)is one of the most common malignant tumors of digestive tract,and its morbidity and mortality are on the rise.This study suggests that many factors are involved in the occurrence and development of CRC.In recent years,studies have found that cholecystectomy can lead to intestinal microbiological disorders,followed by bile acid metabolism disorders,making patients in a high-risk state of colorectal cancer,but little is known about the characteristics of gut microbiota after cholecystectomy.In view of this,the study used high-throughput sequencing technique to find the diversity,relative abundance and distribution of intestinal microorganisms in patients after cholecystectomy.the purpose of this study is to explore the changes of microflora that cholecystectomy may play an important role in the occurrence and development of colorectal cancer.Methods: 20 patients who met the requirements in Shanxi people's Hospital from March2018 to September 2019 were selected,including 4 healthy volunteers(group A),5patients after LC(group B),6 patients with colorectal cancer(group C)and 5 patients with colorectal cancer after LC(group D).A total of 20 stool samples were collected.Then DNA extraction and detection of sample-related bacteria,PCR amplification,product purification,library preparation and library test,Miseq sequencing.Then many information such as species composition,relative abundance,diversity and distribution of bacteria in specific experimental samples were obtained by bioinformatics analysis.Results: In this study,a total of 835502 high-quality amplified feature sequences were obtained from 20 samples(that is,OTU),was clustered according to 99% sequence similarity,and compared with ribosomal RNA database to obtain species annotation information.We counted the proportion of the sequence number to the total sequencenumber of each sample on a total of 7 classification levels.Alpha diversity dilution curve tends to smooth,basically covering 99.9% of bacterial species.There was no significant difference in the diversity of microflora in Shnnon index among groups,and there was no significant difference in the species richness in Chao1 index among groups,and there was no significant difference among groups(P > 0.05).At the gate level,the dominant bacteria in groups A,B,C and D were basically the same,which were Firmicutes,Bacteroidetes and Proteobactenia,which accounted for more than 90% of the intestinal flora.The abundance of Verrucomicrobia in tumor group was significantly higher than that in healthy group(P < 0.05).The relative abundance of TM7 in group B was significantly higher than that in group A(P < 0.05).The relative abundance of Fusobacteria in group D was significantly lower than that in group B(P < 0.05).The relative abundance of Actinobacteria in group D was significantly higher than that in group C(P < 0.05).The relative abundance of Synergistetes in group C was significantly higher than that in other groups(P < 0.05).At the genus level,the relative abundance of Peptostreptococcaceae,Paraprevotellaceae,Verrucomicrobia,Prevotella and Oscillospira in tumor group was significantly higher than that in healthy group(P < 0.05),and the relative abundance of bacteria in tumor group was significantly higher than that in healthy group(P < 0.05),and the relative abundance of Streptococcus albicans in tumor group was significantly higher than that in healthy group(P < 0.05).The relative abundance of Fusobacteria in group B and C was significantly higher than that in group A(P < 0.05).The relative abundance of Megamonas,Paraprevotellaceae,Prevotella,TG5 and Selenomonas in group D was significantly higher than that in group C(P < 0.05).Conclusion:1.Compared with healthy people,the microecology of gut microbiota in patients with colorectal cancer changed significantly.2.There was no significant difference in intestinal microflora diversity between patients after cholecystectomy and healthy people.3.The relative abundance of Fusobacterium in the intestines of patients after cholecystectomy is significantly increased,which may cause intestinal inflammation,promote the growth of conditional pathogenic bacteria and promote the occurrence and development of colorectal cancer.4.The changes of intestinal microecology caused by cholecystectomy may play an important role in the occurrence and development of colorectal cancer.