ABSTRACT
Colorectal cancer (CRC) is a growing cause of mortality in developing countries, warranting investigation into its etiopathogenesis and earlier diagnosis. Here, we investigated the fecal metabolic phenotype of patients with advanced colorectal neoplasia and controls using (1)H-nuclear magnetic resonance (NMR) spectroscopy and multivariate modeling. The fecal microbiota composition was assessed by quantitative real-time PCR as well as Wif-1 methylation levels in stools, serum, and urine and correlated to the metabolic profile of each patient. The predictivity of the model was 0.507 (Q(2)Y), and the explained variance was 0.755 (R(2)Y). Patients with advanced colorectal neoplasia demonstrated increased fecal concentrations of four short-chain fatty acids (valerate, acetate, propionate, and butyrate) and decreased signals relating to ß-glucose, glutamine, and glutamate. The predictive accuracy of the multivariate (1)H NMR model was higher than that of the guaiac-fecal occult blood test and the Wif-1 methylation test for predicting advanced colorectal neoplasia. Correlation analysis between fecal metabolites and bacterial profiles revealed strong associations between Faecalibacterium prausnitzii and Clostridium leptum species with short-chain fatty acids concentration and inverse correlation between Faecalibacterium prausnitzii and glucose. These preliminary results suggest that fecal metabonomics may potentially have a future role in a noninvasive colorectal screening program and may contribute to our understanding of the role of these dysregulated molecules in the cross-talk between the host and its bacterial microbiota.
Subject(s)
Colorectal Neoplasms/diagnosis , Feces/chemistry , Case-Control Studies , Cohort Studies , Humans , Proton Magnetic Resonance SpectroscopyABSTRACT
BACKGROUND AND STUDY AIMS: Urgent endoscopy is often used to diagnose and sometimes treat acute upper gastrointestinal syndromes (hemorrhage, toxic ingestion, and occlusion). However, its suitability concerning the management of lower gastrointestinal conditions in emergency circumstances is controversial. PATIENTS AND METHODS: We studied the role of emergency colonoscopy in diagnosis and treatment of all consecutive patients presenting with acute lower gastrointestinal symptoms referred to our hospital on an emergency basis. All patients were first managed by physicians from the emergency room and/or the intensive care unit (ICU); the treatments included fluid resuscitation, blood transfusion, and antibiotic or cardiotonic as needed. Bowel cleansing was performed to purge the colon of clots, stool, and blood when clinically possible; alternatively, a bowel enema was used. Patients only underwent a computed tomography (CT) scan prior to the colonoscopy in clinically relevant situations. Colonoscopy was performed within 6â-â36 hours after hospitalization or the beginning of the clinical symptoms (hemorrhage, sepsis, colon distension) or occlusion, as assessed by abdominal CT scan. RESULTS: From 2010 to 2015, 603 patients underwent urgent colonoscopy; among them, 214 (36â%) presented with lower GI bleeding, while 264 (44â%) had symptoms suggestive of intestinal ischemia; almost half (49â%, nâ=â295) of the patients were hospitalized in the ICU. Patients received therapies, such as clips (15â%), epinephrine injections (5â%), bipolar coagulation (7â%), or devolvulation (3â%) using colonoscopy or antibiotic therapy when needed. No perforation was observed after colonoscopy and only three cases of hemorrhage recurrence were documented as complications after the procedure. Overall, 192 patients died within 1 month after colonoscopy due to four independent risk situations, as follows: septic shock, heart transplantation, multiorgan failure, and ischemic colitis. Only 67 (35â%) underwent urgent intestinal surgery when ischemic colitis was identified, and this did not have a significant effect on the mortality rate. CONCLUSIONS: Urgent bedside colonoscopy is feasible and safe for routine use. The highest advantage was observed in patients with red blood hemorrhage, diarrhea, and colon distension when symptoms were not associated with multiorgane failure, heart transplantation, or septic shock. As revealed by colonoscopy and pathological features, ischemic colitis is associated with a bad prognosis, and patients experience a higher rate of early mortality regardless of whether they undergo urgent colon surgery.