Determining the optimal route of faecal microbiota transplant in patients with ulcerative colitis: the STOP-Colitis pilot RCT
Authors: Quraishi Mohammed N , Moakes Catherine A , Yalchin Mehmet , Segal Jonathan , Ives Natalie J , Magill Laura , Manzoor Susan E , Gerasimidis Konstantinos , Loi Shrushma , McMullan Christel , Mathers Jonathan , Quince Christopher , Kaur Manjinder , Loman Nicholas J , Sharma Naveen , Hawkey Peter , McCune Victoria , Nichols Ben , Svolos Vaios , Kerbiriou Caroline , McMurray Claire , Beggs Andrew , Hansen Richard , Hart Ailsa L , Gaya Daniel R , Iqbal Tariq H 
Published: September 2024

Background
Ulcerative colitis is an autoimmune reaction to imbalanced colonic microbiome in genetically predisposed patients. There have been four published randomised controlled trials of faecal microbiota transplant versus placebo in ulcerative colitis; three being positive. However, the methodology used varied and mechanistic data were sparse.

Objective
To identify an optimal faecal microbiota transplant delivery route to test in a future efficacy-powered randomised controlled trial.

Design
Prospective, multicentre, open-label, parallel-group, randomised pilot study. Participants were randomised in a 1 : 1 ratio to faecal microbiota transplant by nasogastric or by colonoscopy, minimised by partial Mayo score and current smoking status.

Setting
Three secondary care hospitals in the United Kingdom.

Participants
Thirty adult patients with mild to moderately active ulcerative colitis (partial Mayo score of ≥4 and ≤8).

Interventions
Faecal microbiota transplant samples were prepared at the University of Birmingham Microbiome Treatment Centre and administered to participants either via a nasogastric tube on 4 consecutive days repeated after a month (nasogastric) or by colonoscopy followed by 7 weekly enemas (COLON). Each treatment course was from a single matched donor. Participants and researchers underwent qualitative interviews regarding the faecal microbiota transplant experience.

Main outcome measure
Composite assessment of qualitative and quantitative data based on efficacy, acceptability and safety. Clinical response (primary measure of efficacy) was defined as a ≥3 point and ≥30% reduction in full Mayo score from randomisation to week 8 and a ≥1 point reduction in rectal bleeding subscore or absolute rectal bleeding subscore of 0 or 1.

Results
Thirty ulcerative colitis patients were randomised: 16 to nasogastric; 14 to COLON. Seven participants in the nasogastric arm and two in the COLON arm withdrew from treatment and clinical follow-up. Eight of 16 (50%) nasogastric participants were adherent compared to 12/14 (86%) COLON participants.
Clinical response data were available for 20 of 30 randomised participants. Clinical response was seen in 2/8 (25%) nasogastric participants versus 9/12 (75%) COLON participants: adjusted risk ratio 2.94 (95% CI 0.84 to 10.30). Adverse events were reported in 11/16 (69%) nasogastric participants versus 11/14 (79%) COLON participants. There were three serious adverse events in two nasogastric participants. Faecal microbiota transplant was deemed an acceptable treatment for ulcerative colitis, with greater participant and clinician acceptability for the COLON route.
Faecal microbiota transplant responders had a greater reduction in faecal calprotectin compared to non-responders (t-test p = 0.03) and increase in faecal microbiome diversity (Shannon diversity p < 0.01). In the whole cohort, a negative association between faecal calprotectin and diversity was seen (Kendall’s tau z = −2.8231, p = 0.004757). There were increases in faecal acetate (p = 0.05) and butyrate (p = 0.03) after faecal microbiota transplant intervention, but these were not associated with clinical response.
A limitation was that this was an open-label pilot study, which was not powered to assess for efficacy of faecal microbiota transplant.

Conclusions
Faecal microbiota transplant delivered by the colonic route was considered safe and better tolerated than the nasogastric route. The colonic route was preferred by both participants and clinicians. Mechanistic signals indicated reduction in colonic inflammation and increased microbiome diversity in faecal microbiota transplant responders.

Future work
An efficacy-powered randomised controlled trial.

Trial registration
This trial is registered as ISRCTN74072945 and EudraCT 2015-005753-12.

Funding
This award was funded by the National Institute for Health and Care Research (NIHR) Efficacy and Mechanism Evaluation (EME) programme (NIHR award ref: 13/179/01) and is published in full in Efficacy and Mechanism Evaluation; Vol. 11, No. 14. See the NIHR Funding and Awards website for further award information.