TABLE 5.
ETBF association with IBD or colorectal cancer
Reference (author, yr [reference no.]) | Study design | Location | n | ETBF diagnostic method | Main results | Limitations |
---|---|---|---|---|---|---|
Prindiville et al., 2000 (88) | Endoscopy-based case series, with controls | University of California, Davis, Sacramento, CA | 101 patients with IBD or diarrhea, 69 controls | Stool culture, HT29 cell assay, nested PCR for bft gene DNA extracted from stool | 11/57 (19.3%) patients with active IBD were positive for ETBF by stool PCR vs 0/26 patients with inactive IBD (P < 0.01); 5/18 (27.8%) patients with diarrhea and 2/69 (2.9%) controls were ETBF positive by stool PCR (P < 0.0005); only 4.8% with IBD and 11% with diarrhea were ETBF positive by culture and HT29 cell assay | Limited study design details, including source of controls; stools were frozen for 2 weeks prior to analysis by culture; B. fragilis isolation rates not reported |
Bassett et al., 2004 (7) | Endoscopy-based case series, with controls | London, United Kingdom | 35 patients with IBD and 37 controls; control population included 19 patients with culture-negative diarrhea and 18 patients without diarrhea, all of whom were being investigated by endoscopy for abdominal pain or changes in bowel habits | Nested PCR for bft gene on DNA extracted from luminal washings or biopsies | Of 60 patients with luminal washings available for analysis, 10/28 (35.7%) “controls” (6/14 with diarrhea and 4/14 without diarrhea) and 8/32 (25%) IBD patients were ETBF positive; 7/25 (28%) patients with active IBD and 1/7 (14.3%) patients with inactive IBD were ETBF positive (difference not significant); 4/32 (12.5%) IBD patients and 6/33 (18.2%) controls with colonic biopsies were ETBF positive | Small study with limited details on control population; population defined as controls included patients with and without diarrhea; colonic biopsies and luminal washings were frozen for an unspecified time prior to analysis |
Ulger et al., 2006 (113) | Prospective, consecutive case series with concurrent controls | Istanbul, Turkey | 73 patients with colorectal cancer; 59 healthy controls (age and gender matched) | Stool culture, PCR for bft gene on fecal B. fragilis isolates | B. fragilis isolated from 77% of patients and 68% of controls (difference not significant); 21/56 (38%) patients and 5/40 (12%) controls were ETBF positive (P = 0.009) | Small cross-sectional study without full colon cancer risk factor analysis |