Analysis of gut microbiota change in colorectal adenomatous polyps patients by 16S rRNA sequencing

Objective To explore the characteristics of gut microbiota change in colorectal adenomatous polyps (CAP), which has been considered as precancerous lesion for colorectal cancer. Methods Thirty patients with colon adenomatous polyps (CAP group) and thirty healthy individuals without adenomatous polyps (HC group) who underwent colonoscopy at the First Affiliated Hospital of Kunming Medical University from November 2017 to April 2018 were randomly collected. The biopsy mucosae were collected by endoscopic electrocoagulation, and DNA was extracted to amplify 16S rRNA V3-V4 region, followed high-throughput sequencing with Illumina MiSeq platform. The experimental results were analyzed using Wilcoxon test. Results The alpha diversity of CAP patients was higher than that of healthy controls (Chao & Ace P<0.01). A decreased abundance of Bacteroidetes (FC=0.38) was observed at phylum level(P<0.05). At genus level, the abundances of Bacteroides (FC=0.32) , Escherichia (FC=0.57) , Ruminococcus (FC=0.42) , Blautia (FC=0.27) , and Dorea (FC=0.57) were decreased (P<0.05), but those of Pseudomonas(FC=2.43), Lactococcus(FC=2.84), Geobacillus(FC=2.07), and Acinetibacter(FC=2.36) were increased in CAP patients (P<0.05). Conclusions Compared with healthy volunteers, there are significant differences in the abundance and diversity of the adenoma tissue in CAP patients, indicating that there is an imbalance of gut microbiota in the adenomatous polyps. The imbalance of intestinal microenvironment may contribute to the occurrence and development of CAP. Key words: Colonic neoplasms; Adenomatous polyps; Gastrointestinal microbiome; RNA, ribosomal, 16S; High-throughput nucleotide sequencing