Table 3.
Characteristics of the IBD studies included in this systematic review and meta-analysis
| Study No | Author | Study Year | Study Type | Country | IBD, n | UC, n | CD, n | Diagnostic criteria for IBD | Controls n | Type of control | Mode of diagnosis of SIBO | Methane positive SIBO in IBD, n (%) | Methane positive SIBO in UC, n (%) | Methane positive SIBO in CD, n (%) | Methane positive SIBO in Controls (%) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Shah A et al46 | 2020 | Case control | Australia | 81 | 48 | 33 | Known IBD | 63 | Healthy controls | GBT | 5 (31.3) | 4 (25) | 1 (6.3) | 5 (31.3) |
| 2 | Ricci J et al45 | 2017 | Case control | Brazil | 92 | NA | 92 | *IBD diagnosis | 97 | Nonspecific chronic GI symptoms | GBT | 9 (9.8) | NA | 9 (9.8) | 8 (8.2) |
| 3 | Greco A et al42 | 2015 | Prevalence | Italy | 68 | NA | 68 | Internationally accepted criteria | NA | NA | GBT | 1 (1.5) | NA | 1 (1.5) | NA |
| 4 | Lee JM et al43 | 2015 | Case control | Korea | 107 | 64 | 43 | Known IBD | 30 | Healthy controls | GBT | 3 (2.8) | - | - | 0 (0) |
| 5 | Rana S et al44 | 2013 | Case control | India | 137 | 95 | 42 | Confirmed by colonic biopsy | 115 | Healthy controls | GBT | 4 (2.9) | - | - | 28 (24.3) |
| 6 | Castiglione F et al41 | 2000 | Case control | Italy | 57 | NA | 57 | Known IBD | 40 | Healthy controls | LBT | 2 (3.5) | NA | 2 (3.5) | 0 (0) |
| 7 | Peled Y et al47 | 1987 | Case control | Israel | 84 | 51 | 33 | *IBD diagnosis | 152 | Healthy controls | Breath methane was measured | 18 (21.4) | 16 (31.4) | 2 (6.1) | 76 (50) |
IBD: inflammatory bowel disease; UC: ulcerative colitis; CD: Crohn’s disease; SIBO: small intestinal bacterial overgrowth; LBT: lactulose breath test; GBT: glucose breath test; GI: gastrointestinal; NA: not applicable; *IBD diagnosis: clinical, radiological, colonoscopy and histological diagnosis of IBD.