Impact of the Novel UC-TREAT Diet on the Gut Microbiome and Its Acceptability in Healthy Adults and Adults With Quiescent Ulcerative Colitis

NCT06998277 | Completed

• 1 other identifier: UC-TREAT
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 1

Brief Summary

This will be an open-label dietary intervention study recruiting both healthy adults (≥16y) and adults with quiescent Ulcerative Colitis (UC). The study will span a total of 25 days and is divided into two phases; a 10-day run-in observation period (day -10 to day 0), during which the participant continues with their normal diet, and a 15-day dietary intervention period (day 0 to day 15), during which they will consume a diet high in specific high-fibre foods, fermented foods, berries, and a multivitamin-multimineral tablet. Throughout the study, participants will be asked to provide 3 blood samples (at days -10, 0, and 15), 4 stool and urine samples (at days -15, 0, 10, and 15), and to record a total of 6 days of food intake in provided food diaries. Disease activity, gastrointestinal symptoms, and quality of life will be assessed on 4 occasions (days -10, 0, 10, and 15) via validated questionnaires, and diet acceptability will be assessed at the end of the study.

Conditions

Ulcerative Colitis (UC)

Keywords

Ulcerative Colitis; Dietary therapy

Outcome Measures

Primary Outcomes (2)

• Change in faecal butyrate concentration

  Change faecal butyrate concentration at the end of the diet (day 15) compared to baseline (day 0) and control (day -10).

  At day -10, day 0, day 10, and day 15

• Gastrointestinal symptoms

  Change in gastrointestinal symptoms compared to baseline, assessed via the GI Symptom Rating Scale (GSRS-IBS), will be used to assess GI tolerance of the diet. The GSRS-IBS assesses GI symptoms in 5 domains: pain, bloating, constipation, diarrhoea, and satiety, where a score increase indicates symptom increase.

  At day -10, day 0, day 10, and day 15

Secondary Outcomes (12)

• Faecal metabolites

  At day -10, day 0, day 10, and day 15.

• Faecal microbiota diversity

  At day -10, day 0, day 10, and day 15

• Faecal microbiota composition

  At day -10, day 0, day 10, and day 15

• Faecal calprotectin

  At day -10, day 0, day 10, and day 15.

• Blood inflammatory markers

  At day -10, day 0 and day 15.

Study Arms (2)

Adults with quiescent Ulcerative Colitis

EXPERIMENTAL

Adults with Ulcerative Colitis currently in remission (SCCAI ≤ 5)

Other: Dietary therapy

Healthy controls

EXPERIMENTAL

Healthy adults (≥ 16y)

Other: Dietary therapy

Interventions

Dietary therapy OTHER

Participants with quiescent UC will undergo a 10-day "observational" period followed by 15-days of the UC-TREAT dietary intervention. Disease activity, quality of life, and gastrointestinal symptoms will be assessed throughout

Adults with quiescent Ulcerative Colitis

Eligibility Criteria

• Age: 16 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Individuals with Ulcerative Colitis:
• Confirmed diagnosis of Ulcerative Colitis
• ≥16 years of age
• Motivated to follow the prescribed diet for the study period
• Healthy controls:
• ≥16 years of age
• Motivated to follow the prescribed diet for the study period

You may not qualify if:

• Individuals with Ulcerative Colitis:
• Self-reported active disease (SCCAI≥5) and/or a score ≥2 on any variable within SCCAI
• Previous surgery related to their UC (e.g. colectomy)
• Adjustment of medication dose in the previous month
• Initiation of a new medication in the prior 3 months
• BMI≥35kg/m2
• Pregnancy or lactation
• Regular use of pre/probiotic supplements
• Antibiotics or steroid use in the past 2 months
• Weight fluctuations ≥ 2kg in the past month
• Dietary restrictions (vegetarian, vegan, gluten-free etc)
• Participation in other interventional research.
• Healthy controls:
• Regular use of medication or regular visits to a physician
• History of gut surgery

Sponsors & Collaborators

• University of Glasgow: lead

Study Sites (1)

University of Glasgow

Glasgow, G31 2ER, United Kingdom

Location

MeSH Terms

Conditions

Colitis, Ulcerative

Interventions

Diet Therapy

Condition Hierarchy (Ancestors)

Colitis; Gastroenteritis; Gastrointestinal Diseases; Digestive System Diseases; Inflammatory Bowel Diseases; Colonic Diseases; Intestinal Diseases

Intervention Hierarchy (Ancestors)

Nutrition Therapy; Therapeutics

Study Officials

• Konstantinos Gerasimidis

  University of Glasgow

  PRINCIPAL INVESTIGATOR

• Athanasios Koutsos

  University of Glasgow

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Model Details: Two groups of participants. Adults with ulcerative colitis and healthy adult volunteers; both groups receive the same dietary intervention

Study Record Dates

• First Submitted: May 9, 2025
• First Posted: May 31, 2025
• Study Start: May 8, 2024
• Primary Completion: July 9, 2025
• Study Completion: July 9, 2025
• Last Updated: March 5, 2026

Record last verified: 2026-03

Locations

GB (1)