Accurately Profiling the Changes and Functions of Key Microflora in the Whole Intestinal Microenvironment Based on the Visual Sampling Capsule Endoscopy in Patients With Inflammatory Bowel Disease

This is a prospective, single-center, observational cohort study that will enroll 250 participants: 50 with active Crohn\'s disease, 50 with Crohn\'s disease in remission, 50 with active ulcerative colitis, 50 with ulcerative colitis in remission, and 50 healthy volunteers. Using a novel visual sampling capsule endoscope, intestinal fluid will be collected non-invasively from four intestinal regions: the upper jejunum, the upper ileum, the terminal ileum, and the colon. Saliva and stool samples will also be collected. All samples will be analyzed using 16S rRNA sequencing, metagenomic sequencing, and non-targeted metabolomics. The study aims to characterize the distribution and function of gut microbiota and metabolites across different intestinal regions in patients with inflammatory bowel disease (IBD), to compare active-stage and remission-stage disease, and to compare IBD patients with healthy volunteers, while evaluating the feasibility and safety of the visual sampling capsule endoscope in IBD patients.