Study On The Difference Of Intestinal Flora In Benign And Malignant Colorectal Cancer In Tibet

Objective: Analysis of the differences between intestinal flora of patients with benign and malignant colorectal cancer in Tibet.Functional predictive analysis of intestinal flora between groups was performed to determine the effectiveness of intestinal flora changes in screening for colorectal adenomas.Methods: The clinical data of 94 patients who underwent colonoscopy at the People’s Hospital of Tibet Autonomous Region from 2020 to 2022 were collected and grouped into 4 groups according to the results of colonoscopy,control group(18 cases),nonadenomatous polyp group(29 cases),adenoma group(32 cases),and colorectal cancer group(15 cases).Stool specimens from subjects were collected prior to colorectal microscopy bowel preparation and stored in a -20℃ refrigerator,followed by DNA extraction of bacteria from stool samples,extraction followed by PCR amplification and high-throughput sequencing of the V3-V4 variable region of the 16 S rRNA gene,and finally the composition of the flora of stool samples,followed by a series of in-depth statistical and visualization analyses such as multivariate analysis of species and significance of differences test.Results: 1.α-diversity analysis showed a significant increase in species richness in the colorectal cancer group compared with the control group and the non-adenomatous polyp group,and a significant increase in species diversity in the CRC group compared with the adenoma group.β-diversity analysis showed no significant differences among the four groups.2.The analysis of group differences in terms of phylum and genus levels showed significant changes in intestinal flora abundance between the benign and malignant colorectal tumor and control groups.The LefSe multilevel species difference discrimination analysis between the non-adenomatous polyp group and the colorectal cancer group showed that the non-adenomatous polyp group was dominated by elevated Actinobacteria and Bifidobacterium spp.and the colorectal cancer group was dominated by elevated Bifidobacterium spp.and contributed more to the division between the two groups.And the LefSe multilevel species difference discriminant analysis between the adenomatous and colorectal cancer groups showed that Actinobacteria and Bifidobacterium spp.were predominantly elevated in the adenomatous group and Christensenia spp.were predominantly elevated in the colorectal cancer group,which contributed more to the division of the two groups.3.The abundance of Clostridium phylum、Bifidobacterium phylum 、Clostridium spp.、and Bifidobacterium spp.increased significantly in the colorectal cancer group,while the abundance of Bifidobacterium spp.decreased significantly.4.Phenotype prediction analysis showed that the phenotype Potentially-Pathogenic was significantly more abundant in the colorectal cancer group compared to the control group.Conclusions: Compared with the control group,there were differences in species richness and diversity of colorectal benign and malignant tumor intestinal flora and differences in intestinal flora composition in Tibet.Potentially-Pathogenic(potentially pathogenic)phenotypes may provide a basis for future studies on colorectal adenocarcinoma screening and pathogenesis,and are worthy of further in-depth studies with expanded sample sizes to explore phenotypes that can effectively screen for colorectal cancer.