Trial outcomes (feasibility and clinical outcomes)
| Outcome | Measure | Analysis | ||
| Feasibility outcomes | Participant recruitment | Recruitment/month | Cumulative across all study sites | ≥2 participants/month recruited and retained for duration of study |
| Participant retention | Percent dropout post enrolment | |||
| Participant eligibility | Percent meeting eligibility | |||
| Adverse events | Hospitalisation or ↑PUCAI ≥20×2 consecutive measures | <10% of participants | ||
| Blood specimens | Participant provides all required blood samples | >90% of participants | ||
| Stool specimens | Participants provides all required stool samples | >90% of participants | ||
| Microbiome | Microbiome analyses (16 s rRNA profile, metagenomics) performed for participant at all required time points | >80% of participants | ||
| PUCAI | Participant provides information to calculate all required PUCAI scores | >90% of participants | ||
| Week 30 Endoscopy | Endoscopy obtained | >10% of participants | ||
| Clinical outcomes | Clinical remission (6 weeks) | PUCAI≤10 | χ2 test | |
| Clinical remission (30 weeks) | PUCAI≤10 | χ2 test | ||
| Clinical remission (6–30 weeks) | Sustained PUCAI<10 | χ2 test | ||
| Clinical improvement (6 weeks) | ↓ PUCAI≥15 | χ2 test | ||
| Clinical improvement (6–30 weeks) | Sustained ↓ PUCAI≥15 | χ2 test | ||
| Biological improvement (6 weeks) | ↓ C-reactive protein | t-test | ||
| Biological improvement (6 weeks) | ↓ faecal calprotectin | t-test | ||
| Biological improvement (30 weeks) | ↓ C-reactive protein | t-test | ||
| Biological improvement (30 weeks) | ↓ faecal calprotectin | t-test | ||
| Mucosal healing (30 weeks) | Endoscopy | t-test | ||
| Change in microbiota (6 weeks) | ∆ 16 s rRNA profile, metagenomics profile | t-test, αβ diversity | ||
| Change in microbiota (30 weeks) | ∆ 16 s rRNA profile, metagenomics profile | t-test, αβ diversity | ||
PUCAI, Paediatric Ulcerative Colitis Activity Index.