Table 1.
Summarized characteristics of 45 eligible observational studies.
| Characteristics | Number of studies (%) |
|---|---|
| Participant region | |
| Europe | 10 (22.2) |
| Asia | 26 (57.8) |
| America | 8 (17.8) |
| Other | 1 (2.2) |
| Study design | |
| Prospective study | 20 (44.4) |
| Retrospective study | 25 (55.6) |
| Outcome | |
| Diagnosis | 36 (80.0) |
| Metastasis | 5 (11.1) |
| Survival | 4 (8.9) |
| Reason for colonoscopy | |
| Routine screening | 26 (57.8) |
| qFIT/gFOBT positive | 5 (11.1) |
| Symptoms + Screening | 5 (11.1) |
| Patients recruited at hospital | 9 (20.0) |
| Antibiotic use prior to sample | |
| Not in 1–4 weeks | 7 (15.6) |
| Not in 4–24 weeks | 18 (40.0) |
| At the time of baseline assessment | 3 (6.7) |
| Not mention | 17 (37.7) |
| Sample collection | |
| Faecal samples | 36 (70.0) |
| Tissue samples | 6 (13.3) |
| Oral samples | 1 (2.2) |
| Blood samples | 2 (4.4) |
| Database used for taxonomy assignment | |
| RDP | 15 (33.3) |
| Silva | 6 (13.3) |
| Greengenes | 5 (11.1) |
| Other | 5 (11.1) |
| Not mention | 14 (31.2) |