CST3 and polyp of large intestine: To explore the diagnostic value of the NLR, mean corpuscular haemoglobin (MCH), MCH concentration (MCHC), cystatin C, TG, LDL-C, CEA, P. gingivalis, F. nucleatum, P. intermedia, R. gnavus, B. ovatus, and P. distasonis in colorectal polyps, we plotted ROC curves.