Colon Cancer Study of Fecal Samples in Shanghai, China

To examine how risk for colorectal cancer (CRC) is related to the microbes that inhabit the distal human intestine (the microbiota), we have proposed a large study that compares characteristics of the fecal microbiota in CRC patients and controls in the Shanghai population. In advance of that, we are proposing a small pilot study with the following two objectives: 1) determine participation rates among Shanghai adults, age 50-74 who are positive by fecal immunochemical test (FIT+); and 2) determine the suitability of fecal specimens provided by the participants for microbiome analyses. Each of two Shanghai community health centers, where CRC screening is ongoing, will recruit 25 FIT+ participants (half male; half age 50-64, half age 65-74). Each of the 50 participants will provide informed consent, brief questionnaire data, blood plasma and buffy coat, a urine specimen, and four samples of one stool, which will be frozen. Complete blood count and plasma glucose, cholesterol, and creatinine levels will be determined in real time and returned to the participant. Each participant s plasma, buffy coat, urine, and one pair of fecal samples will be stored frozen for future genetic or other assays. DNA will be extracted from the second pair of fecal samples from each participant (n=100 vials), amplified for 16S rRNA genes, and sequenced to determine fecal microbiome profiles. Participation will be deemed unsatisfactory if participation is <30% overall (95% confidence interval 17% - 43% for N=50 participants), or if there are <20 male, female, younger, or older participants. Specimen quality will be deemed unsatisfactory if the intraclass correlation coefficient (ICC) is <0.70 (95% confidence interval 0.53 0.82 for N=50 paired vials) for the Shannon index estimate of microbiome alpha diversity. As amended, the two community health centers will recruit up to 600 additional adults presenting for CRC screening, irrespective of FITstatus, who will be asked to provide saliva as well as the other specimens.