Predictive Value of Innovative Prognostic Markers (Gut Microbiota, Sarcopenia, Metabolic Syndrome and Obesity) on Surgical and Oncologic Results in the Management of Sporadic Colorectal Adenocarcinoma.

The METABIOTE study will be systematically proposed to patients selected for sporadic CRC surgery during the first preoperative outpatient visit. The attending surgeon will double-check all inclusion and exclusion criteria. An oral and written information will be given to patients, presenting the study. Then, the following data will be collected propectively: * Socio-demographic and medical data (personal and familial medical history, current treatments, comorbidities, allergies, Body Mass Index (BMI), ASA score…) * Blood tests results, including nutritional, hepatic assessment and exploration of a lipidic abnormality. * Body composition profile: Metabolic syndrome screening, BMI, waist circumference, sarcopenia (skeletal muscle index calculation on CT scan). * Thoraco-abdomino-pelvic CT scan: sarcopenia, hepatic and splenic density, thanks to a dedicated software (Slice-O-Matic). Following surgery will be collected : * Pathological data (TNM stage, MSI, RAS and BRAF status…) * Surgical results (30-day postoperative medical and surgical morbidity and 90-day postoperative mortality) * Oncologic results (Overall survival, Disease free survival…) * Metabolic profile evolution: sarcopenia (SMI), BMI and waist circumference after 3, 6, 12 and 36 months, postoperatively. Intraoperatively, samples of peritumoral mucosa and tumor specimen and rectal stools will be frozen (-80°) and moved to the research unit for microbiota analysis. Interest bacteria will be grown on selective gelosis and pathogenic E coli will be identified using PCR as well as other specific bacteria involved in CRC. Moreover, global microbiota modifications will be observed using high-throughput sequencing of the bacterial 16S rRNA gene. These data will be associated with body composition profile, clinical data, surgical and oncologic results, and pathological data thanks to a multivariate analysis. The patients will be monitored according to the Digestive Oncology french recommendations (TNCD).