IDDF2019-ABS-0226 The potential intestinal fungal biomarkers in patients with colonic polyps

BackgroundEpidemiological data show that at least 80% of colorectal cancers evolved from colon polyps, and early intervention can greatly reduce the risk of colorectal cancer. However, the cost of a colonoscopy is high and the acceptance is low, which causes the patient to miss the opportunity of diagnosis and treatment. Therefore, exploring new and effective colon polyps screening methods is of great significance for the early diagnosis and treatment of colorectal cancer.MethodsWe conducted a randomized controlled trial in Zhongshan Hospital Affiliated to Xiamen University, Xiamen, China. We recruited volunteers with normal hematology and colonoscopy as controls. Patients with polyps were diagnosed with colonoscopy and histopathology. Volunteer’s feces were subjected to Internal Transcribed Spacer (ITS) analysis for fungi, and the microbial community structure changes were investigated by R-analysis method.Results12 controls and 17 patients were enrolled in our project. The results showed that compared with the control, the fungal species richness of colon polyps decreased, and the species community distribution was significantly shifted. The abundance of Ascomycete in patients was up to 50.9%, of which Xylaria was three times higher than the control. In addition, pathogens such as Candida, Saccharomyces, Passalora et al are also doubled in patients. Further, combining Lefse analysis, four fungi of Candida, Xylaria, Saccharomyces and Aspergillus were significantly increased in patients, and the abundance in different individuals was relatively stable. The ROC curve was used to analyze the sensitivity and specificity of these four species to discover colon polyps, and the AUCs were obtained as 0.89583, 0.62037, 0.65714, 0.66667 with the accuracies of 0.857, 0.8, 0.667, 0.7333. In order to improve the specificity of the model, these four species were simultaneously used in the model, and the AUC was 0.75 with an accuracy of 0.667, which up to the clinical laboratory standard. However, there were no differences in fungal community structure between patients with different pathological types and number.ConclusionsIn summary, this study investigated the fungal community structure of polyps and elucidate the characteristics of patients with pathogenic fungi. What’s more, this subject has established innovative intestinal microorganisms as polyps screening biomarkers.