Background: Inflammatory bowel disease (IBD) is showing an increasing incidence in China, posing a significant threat to public health. IBD patients exhibit gut microbiota dysbiosis, and detection of IBD-associated gut microbes can aid in diagnosis and management. Methods: We developed a 2D-PCR method based on base-quenching probe technology, which allowed closed-tube, single-tube simultaneous detection of four IBD-associated microbes: Ruminococcus gnavus, Veillonella spp. Ruminococcus torques , and Clostridioides difficile . Clinical fecal samples were tested including 224 IBD patients, 112 patients with other digestive diseases, and 57 healthy controls. Results: The 2D-PCR method was demonstrated a detection limit of 10 copies/μL and no cross-reactivity between primers. The combination of R. gnavus and Veillonella spp. along with fecal occult blood test (FOBT), distinguished IBD patients from healthy controls (AUC = 0.9224, 95% CI 0.8747– 0.9701, p < 0.0001, Se = 85.11%, Sp = 92.59%) and IBD from other digestive diseases (AUC = 0.7984, 95% CI 0.7132– 0.8837, p < 0.0001, Se = 66.67%, Sp = 84.95%). R. torques was exclusively detected in Crohn’s disease patients (8.33% positivity), suggesting its potential as a specific diagnostic marker, albeit with limited sensitivity. C. difficile was detected in 8.93% of IBD patients and identifying such infections can guide antibiotic therapy and improve patient outcomes. Conclusion: The 2D-PCR method is cost-effective and suitable for widespread clinical application with low technical and instrumental requirements. These detected microbial markers could aid in IBD diagnosis, differential diagnosis, and treatment guidance, serving as noninvasive biomarkers and expanding the clinical utility of gut microbiota in IBD management. Keywords: inflammatory bowel disease, microbiology, PCR, molecular diagnostics
Li et al. (Sun,) studied this question.