XV. 3 Profile 3: Ulcerative Colitis (UC)
In ulcerative colitis, FMT can bring remission for a subset of patients when it draws on multiple donors and weeks of patient consolidation.
| Parameter | UC-specific detail |
|---|---|
| Evidence level | ★★★☆☆ Moderate. Multiple RCTs show benefit in subset of patients. Response rates 24–32% remission in pooled analysis. Not yet standard of care. |
| Mechanism of dysbiosis | Th17-dominant mucosal immune activation; Faecalibacterium prausnitzii depletion; reduced butyrate production; increased mucosal permeability; microbiota-driven cytokine amplification. |
| Primary microbiota targets | Restore F. prausnitzii, Roseburia, Lachnospiraceae butyrate producers. Reduce Proteobacteria and Fusobacterium nucleatum. Normalize mucosal IgA secretion. |
| Protocol modification | Full 4-phase protocol including Phase 0 compatibility assessment. Multiple donors tested; donor with highest anti-inflammatory microbiota profile selected. Extended consolidation (8+ weeks) associated with higher remission rates in RCTs. |
| Minimum transfer duration | 60 days from induction. Evidence supports ≥8 weeks of active dosing for durable response (Moayyedi et al. 2015; Paramsothy et al. 2017). |
| Priority exposome focus | High dietary fiber + Mediterranean diet pattern. Strict stress management (HPA axis directly modulates mucosal inflammation). Sleep regularization. Anti-inflammatory omega-3 intake. Minimize NSAIDs. |
| Expected response timeline | Symptom improvement: 4–8 weeks. Endoscopic remission (if assessed): 8–12 weeks. Clinical response precedes histological healing – partial improvement early does not indicate failure. |
| Warning signs (UC-specific) | Bloody diarrhea worsening after initial improvement (flare). Fever + bloody stool (rule out superimposed infection). Significant weight loss during consolidation. Severe abdominal pain (toxic colitis). |
Table 14 – Clinical profile: Ulcerative Colitis (UC) # Protocol parameters, evidence level, and clinical modifications specific to UC.
The FOCUS trial 5-year follow-up (Paramsothy et al., Gastroenterology 2024) demonstrated sustained clinical remission in 26% of the active multi-donor FMT group vs. 11% placebo – the first long-term durability data for UC-FMT . Multi-donor approach (3–5 donor pooled preparation) is established to outperform single-donor FMT in preserving strain diversity.
UC-FMT Clinical Protocol (2024)
| Parameter | Specification |
|---|---|
| Indication window | Mild-moderate active UC (Mayo 4–9), biologic-naïve or after 1st biologic failure |
| Induction | Colonoscopic FMT after endoscopic remission achieved + 6 weeks daily enema |
| Consolidation | Capsule FMT 8–12 weeks: 1×/week |
| Donor pool | Multi-donor (3–5), enriched with: Roseburia, Faecalibacterium, Bifidobacterium |
| Primary endpoint | Mayo score ≥2 point reduction + endoscopic improvement |
| Expected response | 36% week-8 clinical remission, 26% sustained 5-year remission |
| Refractory cases | Vedolizumab[G] + FMT combination (FACTU results: 41% response) |
Clinical Pearl
UC-FMT does not replace conventional therapy (5-ASA, corticosteroids, biologics) but complements it. The precise combination algorithm is provided in the 2024 ECCO consensus . Patients must be informed: FMT is a therapeutic option but is not currently routine standard care in many countries, and application takes place within clinical trial protocols.