Clinical trial NCT06998277: Impact of the Novel UC-TREAT Diet on the Gut Microbiome and Its Acceptability in Healthy Adults and Adults With Quiescent Ulcerative Colitis
Official title: Impact of the Novel UC-TREAT Diet on the Gut Microbiome and Its Acceptability in Healthy Adults and Adults With Quiescent Ulcerative Colitis
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Ulcerative Colitis (UC)
Keywords: Ulcerative Colitis
Dietary therapy
Lead sponsor: University of Glasgow
Sponsor class: OTHER
First posted: 2025-05-31
Enrollment: 36
Sex: ALL
Minimum age (years): 16
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Two groups of participants. Adults with ulcerative colitis and healthy adult volunteers; both groups receive the same dietary intervention
Primary purpose: TREATMENT

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.

Detailed description: 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" observational period and a 15-day dietary intervention period.

During the 10-day "run-in" observational period (day -15 to day 0), participants will be asked to continue with their regular habitual diet and record their food intake in a provided estimated weight food diary with food photography for the first 3 of the 10 days. After this "run-in" period, participants will start the 15-day UC-TREAT dietary intervention (day 0 to day 15), where they will consume daily micronutrient supplements, increase intake of berries, and gradually increase intake of dietary fibre and fermented foods.

For the first 5 days of the dietary intervention, participants will enter a "ramping" phase, where, with the guidance of the researchers, they will consume 2 portions of berries (blueberries and raspberries) and 1 multivitamin-multimineral tablet each day. Participants will increase their fibre intake by 1 serving of high-fibre food per day until they reach an additional intake of 35g/d and increase fermented food intake by approximately 1 serving per day until they reach at least 5 servings per day. For the final 10 days of the UC-TREAT dietary intervention, participants will enter a "maintenance phase", where they will maintain this additional 35g of fibre intake and at least 5 servings of fermented foods daily. Participants will be asked to record 3 days of food intake in the provided food diaries during this period. The purpose of the ramping period is to reduce the sudden onset of functional abdominal symptoms typically associated with a rapid increase in dietary fibre consumption, including flatulence, bloating, and abdominal cramping. 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 -10, 0, 10, and 15), and to record a total of 6 days of food intake in provided food diaries.

On 4 occasions (days -10, 0, 10, and 15), all participants will be asked to complete a questionnaire assessing their gastrointestinal symptoms (GSRS-IBS), while participants with UC will also be asked to complete a questionnaire assessing their disease-specific quality of life (sIBDQ) and self-reported disease activity (SCCAI). At the end of the study (day 15), all participants will also be asked to complete an acceptability questionnaire to assess their tolerance of the diet.

Eligibility criteria: Inclusion Criteria:

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

Exclusion Criteria:

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
* 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.

Primary outcomes:
measure: Change in faecal butyrate concentration
timeFrame: At day -10, day 0, day 10, and day 15
measure: Gastrointestinal symptoms
timeFrame: At day -10, day 0, day 10, and day 15
Secondary outcomes:
measure: Faecal metabolites
timeFrame: At day -10, day 0, day 10, and day 15.
measure: Faecal microbiota diversity
timeFrame: At day -10, day 0, day 10, and day 15
measure: Faecal microbiota composition
timeFrame: At day -10, day 0, day 10, and day 15
measure: Faecal calprotectin
timeFrame: At day -10, day 0, day 10, and day 15.
measure: Blood inflammatory markers
timeFrame: At day -10, day 0 and day 15.
measure: Clinical disease activity
timeFrame: At day -10, day 0, day 10, and day 15.
measure: Diet acceptability
timeFrame: Once at the end of the study period (day 15).
measure: Quality of life (sIBDQ)
timeFrame: At day -10, day 0, day 10, and day 15.
measure: Dietary adherence
timeFrame: Throughout the dietary intervention period (~15 days).
measure: Dietary intake
timeFrame: 3 days on 2 occasions (6 days in total) throughout the entire study period (~25 days).
measure: Stool form
timeFrame: At day -10, day 0, day 10, and day 15.
measure: Body composition
timeFrame: At day -10, day 0 and day 15.
Other outcomes:
Locations:
city: Glasgow
country: United Kingdom
facility: University of Glasgow
Study officials:
affiliation: University of Glasgow
name: Konstantinos Gerasimidis
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Glasgow
name: Athanasios Koutsos
role: PRINCIPAL_INVESTIGATOR
References: