Investigators will conduct a multicenter prospective case control study consisting of three stages.~In the first stage, investigators will collect clinical data and blood, urine and stool samples from diabetic patients with chronic wound (CWD), diabetic patient without newly identified wound (NWD) and patients without diabetes (ND to discover the candidate bioindicator with differences through combined high-throughput non targeted detection.~In the second stage, investigators will expand the sample size and collect the clinical data and biological samples (blood, urine and stool) of the CWD,NWD and ND participants to verify the difference of the candidate bioindicator in the first stage by targeted technologies.~In the third stage, investigators will collect the clinical data and biological samples (blood, urine and stool) of the CWD and NWD participants to evaluate the value of these candidate bioindicators as biomarkers.
This study aims to discover, verify and evaluate the potential biomarkers with regard to the diagnosis, prognostic and/or prediction of diabetic chronic wounds.