Relative Fecalabundance Of Clostridium Symbiosum For Detection Of Colorectal Adenomas And Adenocarcinoma

Objectives: This study focuses on identifying one or more species of gut microbiota the relative abundance of which may change along with different stages of colorectal neoplasia and by which a new model for detection of early and late stage colorectal cancer may be established.Methods: A total number of 1137 subjects from 3 different centers was enrolled in this study.Fecal DNA was extracted and q PCR was done for all subjects to quantify the microbial relative abundance of the potiential microbiota for different gut neoplasia.Subsequent comparison with the routine screen methods such as fecal occult blood test and serum CEA test was done and new models were established using markers above to assist the diagnosis in different stages of colorectal neoplasia.All results were validated in an independent cohort.Results:The relative abundance of Fusobacterium nucleatum and Clostridium symbiosum was significantly elevated along with healthy control-adenomas-early stage colorectal cancer-late stage colorectal cancer and the latter exhibited stronger trend with long-lasting high abundance after curative surgery.The relative abundance of clostridium symbiosum showed stronger ability in predicting advanced colorectal adenoma(AUC=0.626)and early stage colorectal cancer(AUC=0.659)than fusobacterium nucleatum and fecal occult blood test or serum CEA test.For late stage colorectal cancer,the relative abundance of Fusobacterium nucleatum and clostridium symbiosum shared higher sensitivity than fecal occult blood test or serum CEA test.Combination of these markers may reach even better diagnositic power against early stage colorectal cancer(AUC=0.740)and late stage colorectal cancer(AUC=0.898).Conclusion:The relative abundance of Clostridium symbiosum rises through gut adenomas to cancers and thus may be more helpful in diagnosis of precancerous lesions and early colorectal cancer than existing screening methods.Combining Fusobacterium nucleatum as well as fecal occult blood test and serum CEA test may strengthen this trend and further assist in identifying late stage colorectal cancer.