Ulcerative Colitis (UC)UC-TREATNCT06998277
Impact of the Novel UC-TREAT Diet on the Gut Microbiome and Its Acceptability in Healthy Adults and Adults With Quiescent Ulcerative Colitis
A study testing Dietary therapy in people with Ulcerative Colitis (UC), run by University of Glasgow at 1 site in United Kingdom.
Trial 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… Read more about this study
- Who is it for?
- Ages 16 years and olderHealthy volunteers can take part
- Conditions the study is for
- Ulcerative Colitis (UC)
- What is being tested?
- Dietary therapy
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 36 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 8 May 2024to 9 Jul 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 16 years and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
Show all 22Show fewer
- 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.
Trial locations and contacts
1 site in 1 country.
About this study
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.
Read the 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.
- Conditions
- Ulcerative Colitis (UC)
- Being tested
- Dietary therapy
- Keywords
- Ulcerative Colitis, Dietary therapy
- Medical subject headings
- Colitis, Ulcerative
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Dietary therapyOther
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
Dietary therapyOther
Healthy participants will undergo a 10-day "observational" period, followed by 15-days of the UC-TREAT dietary intervention. Gastrointestinal symptoms will be assessed throughout.
| Study group | Role | What they receive |
|---|---|---|
| Adults with quiescent Ulcerative Colitis | Experimental | Adults with Ulcerative Colitis currently in remission (SCCAI ≤ 5) Receives: Other: Dietary therapy |
| Healthy controls | Experimental | Healthy adults (≥ 16y) Receives: Other: Dietary therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
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).
Measured: 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.
Measured: At day -10, day 0, day 10, and day 15
Secondary outcomes (12)
Faecal metabolites
Targeted faecal metabolites will be assessed via gas chromatography, colorimetry, and NMR metabolomics to evaluate changes to the faecal metabolome throughout the study period
Measured: At day -10, day 0, day 10, and day 15.
Faecal microbiota diversity
Change in faecal microbiota alpha-diversity during the diet compared to baseline and control.
Measured: At day -10, day 0, day 10, and day 15
Faecal microbiota composition
Change in faecal microbiota composition (beta-diversity and taxa abundance) during the diet compared to baseline and control, as well as the differences between participants with UC and healthy controls.
Measured: At day -10, day 0, day 10, and day 15
Faecal calprotectin
Faecal calprotectin will be measured in all participants to assess any changes in gut inflammation throughout the study.
Measured: At day -10, day 0, day 10, and day 15.
Blood inflammatory markers
Biomarkers of inflammation in plasma, such as C-reactive protein, will be measured in fasted blood samples.
Measured: At day -10, day 0 and day 15.
Clinical disease activity
Clinical disease activity will be assessed via the Simple Clinical Colitis Activity Index (SCCAI), where a score increase indicates disease worsening and a score ≥ 5 indicates active disease.
Measured: At day -10, day 0, day 10, and day 15.
Diet acceptability
Acceptability of the diet will be assessed in all participants at the end of the study, using a study specific 9-item questionnaire employing a 5-point likhert scale ("Strongly Agree", "Agree", "No opinion", "Disagree", "Strongly Disagree").
Measured: Once at the end of the study period (day 15).
Quality of life (sIBDQ)
Quality of life will be assessed in participants with Ulcerative Colitis via the short-Inflammatory Bowel Disease Questionnaire (sIBDQ). This questionnaire assesses QoL in 4 domains: bowel, social, emotional, and systemic, where a score increase indicates improve quality of life.
Measured: At day -10, day 0, day 10, and day 15.
Dietary adherence
Adherence to the prescribed diet will be assessed using daily food checklists.
Measured: Throughout the dietary intervention period (~15 days).
Dietary intake
Dietary intake will be assessed via 3-day, estimated-portion food diaries supplemented with food photography. Food diaries will be recorded during the observational phase and during the dietary intervention phase of the study.
Measured: 3 days on 2 occasions (6 days in total) throughout the entire study period (~25 days).
Stool form
Bristol Stool Chart Rating (BSCR) and percentage water content will be assessed to inform of any changes to stool form throughout the study.
Measured: At day -10, day 0, day 10, and day 15.
Body composition
BMI and %fat mass will be assessed throughout the study to evaluate any changes to body composition throughout the study.
Measured: At day -10, day 0 and day 15.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 May 2025
- Study start8 May 2024
- Primary completion9 Jul 2025
- Study completion9 Jul 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Ulcerative Colitis (UC)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- Two groups of participants. Adults with ulcerative colitis and healthy adult volunteers; both groups receive the same dietary intervention
- Masking
- None (open label)
- Enrolment
- 36 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Glasgow
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dr Konstantinos Gerasimidis, University of Glasgow
- Investigators
- Konstantinos Gerasimidis, Principal investigator, University of GlasgowAthanasios Koutsos, Principal investigator, University of Glasgow
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06998277
- Sponsor's protocol ID
- UC-TREAT
- Acronym
- UC-TREAT
- Status last verified
- Mar 2026
- First submitted
- 9 May 2025
- Last updated
- 5 Mar 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 5 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- 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
- ClinicalTrials.gov ID
- NCT06998277
- Acronym / sponsor ID
- UC-TREAT / UC-TREAT
- Conditions
- Ulcerative Colitis (UC)
- Keywords
- Ulcerative Colitis, Dietary therapy
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 36 participants (actual)
- Lead sponsor
- University of GlasgowUniversity, hospital or other
- Study start
- 8 May 2024 (actual)
- Primary completion
- 9 Jul 2025 (actual)
- Study completion
- 9 Jul 2025 (actual)
- First posted
- 31 May 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Two groups of participants. Adults with ulcerative colitis and healthy adult volunteers; both groups receive the same dietary intervention
| Arm | Type | Receives |
|---|---|---|
| Adults with quiescent Ulcerative Colitis | Experimental | Other: Dietary therapyAdults with Ulcerative Colitis currently in remission (SCCAI ≤ 5) |
| Healthy controls | Experimental | Other: Dietary therapyHealthy adults (≥ 16y) |
Who may qualify
- Ages
- 16 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (7 listed)
- Confirmed diagnosis of Ulcerative Colitis
- ≥16 years of age
- Motivated to follow the prescribed diet for the study period
- ≥16 years of age
- Motivated to follow the prescribed diet for the study period
Key exclusion criteria (22 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Dietary therapyParticipants 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 | Other | Adults with quiescent Ulcerative Colitis |
| Dietary therapyHealthy participants will undergo a 10-day "observational" period, followed by 15-days of the UC-TREAT dietary intervention. Gastrointestinal symptoms will be assessed throughout. | Other | Healthy controls |
Primary outcome
Change in faecal butyrate concentration
Time frame: At day -10, day 0, day 10, and day 15
Change faecal butyrate concentration at the end of the diet (day 15) compared to baseline (day 0) and control (day -10).
Gastrointestinal symptoms
Time frame: At day -10, day 0, day 10, and day 15
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.
12 secondary outcomes
Faecal metabolites
Time frame: At day -10, day 0, day 10, and day 15.
Faecal microbiota diversity
Time frame: At day -10, day 0, day 10, and day 15
Faecal microbiota composition
Time frame: At day -10, day 0, day 10, and day 15
Faecal calprotectin
Time frame: At day -10, day 0, day 10, and day 15.
Blood inflammatory markers
Time frame: At day -10, day 0 and day 15.
Clinical disease activity
Time frame: At day -10, day 0, day 10, and day 15.
Diet acceptability
Time frame: Once at the end of the study period (day 15).
Quality of life (sIBDQ)
Time frame: At day -10, day 0, day 10, and day 15.
Dietary adherence
Time frame: Throughout the dietary intervention period (~15 days).
Dietary intake
Time frame: 3 days on 2 occasions (6 days in total) throughout the entire study period (~25 days).
Stool form
Time frame: At day -10, day 0, day 10, and day 15.
Body composition
Time frame: At day -10, day 0 and day 15.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Mar 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Konstantinos Gerasimidis principal investigator
University of Glasgow
Athanasios Koutsos principal investigator
University of Glasgow
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Dietary therapy in people with Ulcerative Colitis (UC), run by University of Glasgow at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 22 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in faecal butyrate concentration (time frame: At day -10, day 0, day 10, and day 15). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Mar 2026.