Analysis of Intestinal Microflora Combined With DNA Methylation in Stool to Detect Colorectal Cancer

Introduction: Colorectal cancer (CRC) has the third highest incidence rate and the fourth mortality rate in the world. Traditional colonoscopy as an invasive examination method cannot be widely used in screening for colorectal neoplasia. The fecal immunochemical test has some limitations in sensitivity. Also, race and regional differences may affect results. Abnormality in the composition of the gut microbiota has been implicated as a potentially important etiologic factor in the initiation and progression of colorectal cancer. Analyzing fecal flora and exfoliated cell genes may represent a new screening tool for colorectal cancer.This research aims to use 16S rRNA to compare differences in fecal flora between colorectal cancer patients and healthy controls. These data combined with DNA findings of fecal exfoliated cells may further clarify this difference to build a model for screening early colorectal cancer in Chinese people. Methods and analysis: In total, 300 patients with positive colonoscopy results and 200 health controls will be recruited. All participants will complete an information form and questionnaires. Fecal samples will be examined by 16S rRNA analysis. Gene methylation levels will be detected in fecal exfoliated cells. Models of related intestinal microbiota and methylation genes will be built. Receiver operating characteristic (ROC) curve analysis will be used to select some models with appropriate sensitivity and specificity.The models will be further validated by multicenter studys.