Fred M. Konikoff

BACKGROUND AND STUDY AIMS: A second-generation capsule endoscopy system, using the PillCam Colon 2, was developed to increase sensitivity for colorectal polyp detection compared with the first-generation system. The performance of this new system is reported. PATIENTS AND METHODS: In a five-center feasibility study, second-generation capsule endoscopy was prospectively compared with conventional colonoscopy as gold standard for the detection of colorectal polyps and other colonic disease, in a cohort of patients scheduled for colonoscopy and having known or suspected colonic disease. Colonoscopy was independently performed within 10 hours after capsule ingestion. Capsule-positive but colonoscopy-negative cases were counted as false-positive. RESULTS: 104 patients (mean age 49.8 years) were enrolled; data from 98 were analyzed. Patient rate for polyps of any size was 44 %, 53 % of these patients having adenomas. No adverse events related to either procedure were reported. The capsule sensitivity for the detection of patients with polyps >or= 6 mm was 89 % (95 % confidence interval [CI] 70 - 97) and for those with polyps >or= 10 mm it was 88 % (95 %CI 56 - 98), with specificities of 76 % (95 %CI 72 - 78) and 89 % (95 %CI 86 - 90), respectively. Both polyps missed by colonoscopy and mismatch in polyp size by study definition lowered specificity. Overall colon cleanliness for capsule endoscopy was adequate in 78 % of patients (95 %CI 68 - 86). CONCLUSIONS: The new second-generation colon capsule endoscopy is a safe and effective method for visualizing the colon and detecting colonic lesions. Sensitivity and specificity for detecting colorectal polyps appear to be very good, suggesting a potential for improved accuracy compared with the first-generation system. Further prospective and comparative studies are needed.

Cholecystectomy, surgical removal of the gallbladder, changes bile flow to the intestine and can therefore alter the bidirectional interactions between bile acids (BAs) and the intestinal microbiota. We quantified and correlated BAs and bacterial community composition in gallstone patients scheduled for cholecystectomy before and after the procedure, using gas-liquid chromatography and 16S rRNA amplicon sequencing, followed by quantitative real-time polymerase chain reaction of the phylum Bacteroidetes. Gallstone patients had higher overall concentrations of faecal BAs and a decreased microbial diversity, accompanied by a reduction in the beneficial genus Roseburia and an enrichment of the uncultivated genus Oscillospira, compared with controls. These two genera may thus serve as biomarkers for symptomatic gallstone formation. Oscillospira was correlated positively with secondary BAs and negatively with primary BAs, while the phylum Bacteroidetes showed an opposite trend. Cholecystectomy resulted in no substantial change in patients' faecal BAs. However, bacterial composition was significantly altered, with a significant increase in the phylum Bacteroidetes. Given that cholecystectomy has been associated with a higher risk of colorectal cancer and that members of the Bacteroidetes are increased in that disease, microbial consequences of cholecystectomy should be further explored.