Irritable Bowel Syndrome (IBS)NCT07052890
Curcumin, Vitamin D and Green Tea in IBS-D
A study testing Curcumin, vitamin d and green tea extract in people with Irritable Bowel Syndrome (IBS) and Irritable Bowel Syndrome With Diarrhea (IBS-D), run by Dr Anthony Hobson at 3 sites in United Kingdom.
Trial summary
Irritable Bowel Syndrome (IBS) is a highly prevalent condition of the gastrointestinal tract that has significant impact on sufferer's quality of life. The diarrhoea variant (IBS-D) makes up around one third of all IBS sufferers. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Irritable Bowel Syndrome (IBS), Irritable Bowel Syndrome With Diarrhea (IBS-D)
- What is being tested?
- Curcumin, vitamin d and green tea extract
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 78 participants
- Where
- 3 sitesUnited Kingdom
- Study dates
- 19 Sep 2024to 30 Jan 2026
- 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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Participant has provided written informed consent before participating in the study after being given a full description of the study and prior to any study-specific procedures being performed.
- Participant has irritable bowel syndrome with diarrhoea (IBS-D), as defined by the Rome IV criteria.
- Participant has an IBS-SSS score of >175 at screening.
- Participant is a male or non-pregnant female and is ≥18 years of age
- Participant can communicate well with the Investigator and to comply with the requirements for the entire study.
- Participant has capacity to understand written English.
- Participant has a body mass index (BMI) of 18.5 - 39.9kg/m2 (bounds included).
- Participant agrees to follow all pre-test preparation before breath testing visits.
Who cannot join
- Prior abdominal surgery other than appendectomy and cholecystectomy.
- Known hypercalcaemia.
- Participating in another trial or taken an IMP within the last 1 month.
- Females who report to be pregnant or lactating
- Unwilling to maintain stable doses of permitted concomitant medication
- Unwilling to maintain a stable diet for the duration of the trial
Show all 19Show fewer
- Being in the opinion of the investigator unsuitable
- Insufficient knowledge of English to complete the daily bowel diary and food diary
- Hypersensitivity to any component of the supplement
- Hypersensitivity or known allergy to lactulose
- Drug interactions with any component of the supplement
- Consumption of antibiotics, prebiotics or probiotics (in food products or as supplements) in the last 4 weeks prior to, or during the study.
- Vitamin D two week washout
- Participants who have received bowel preparation for investigative procedures in the 4 weeks prior to the study
- Individuals declaring additional specific dietary needs
- Inflammatory bowel disease or coeliac disease
- Any other condition, deemed by the investigator, that may be causing their symptoms
- No major co-morbidity.
- Participant is involved in this study as an Investigator, sub-Investigator, study coordinator, other study staff, or Sponsor member.
Trial locations and contacts
3 sites in 1 country.
United Kingdom3 sites
The Functional Gut Clinic Cambridge
Cambridge, CB2 1LR
The Functional Gut Clinic London
London, NW1 6PU
The Functional Gut Clinic Manchester
Manchester, m3 4bg
About this study
Official title: Role of a Food Supplement Containing Curcumin, Green Tea and Vitamin D on Symptom Control in Diarrhoea Predominant Irritable Bowel Syndrome (IBS-D)
Irritable Bowel Syndrome (IBS) is a highly prevalent condition of the gastrointestinal tract that has significant impact on sufferer's quality of life. The diarrhoea variant (IBS-D) makes up around one third of all IBS sufferers. There is currently a lack of both effective pharmacological and non-pharmacological treatments for IBS-D.
Three food supplements: Green tea, vitamin D and curcumin have all been shown to demonstrate benefit in either reducing symptoms in IBS or diarrhoea as individual ingredients, but have never been tested in combination to assess their effectiveness in IBS. This research study aims to examine the effectiveness of green tea, vitamin D and curcumin in combination compared to a placebo capsule in individual suffering from IBS-D.
The study will aim to enroll 78 participants with IBS-D and utilise a placebo-controlled double blind design. The study will consist of a 2 week screening period, a 4 week randomised treatment period (50% participants to receive placebo, 50% to receive active treatment), followed by a 4 week open label treatment period (all participants to receive the active study product).
- Being tested
- Curcumin, vitamin d and green tea extract, Placebo Capsule(s)
- Medical subject headings
- Irritable Bowel Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Curcumin, vitamin d and green tea extractDietary supplement
A combination of the following ingrediants per 4 capsules:
CurcuWin® 1000mg - of which 200mg Curcuminoids
Green Tea Extract 400mg - (0.1-0.5% caffeine)
Vitamin D₃ 50 µg 2000IU
Placebo Capsule(s)Dietary supplement
Placebo - identical capsules containing inert color matched power
| Study group | Role | What they receive |
|---|---|---|
| Placebo | Placebo comparator | 28 days placebo capsules 4x daily, followed by 28 days of open label active treatment Receives: Dietary Supplement: Placebo Capsule(s) |
| Curcumin, Vitamin D and Green tea | Experimental | 28 days Curcumin, Vitamin D and Green tea capsules 4x daily, followed by a further 28 days of this treatment but non-blinded (open label) Receives: Dietary Supplement: Curcumin, vitamin d and green tea extract; Dietary Supplement: Placebo Capsule(s) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean decrease of Irritable bowel syndrome symptom severity score (IBS-SSS)
Mean change in IBS-SSS at the end of the randomised treatment phase between Active and placebo arms.
The IBS-SSS is numeric score based on 5 questions (each rated 0-100), with a total minimum score of 0 and maximum of 500, with a higher score indicating greater severity of symptoms.
Measured: From Enrollment to end of 4 week randomised treatment period
Secondary outcomes (9)
Use of rescue medication
Average change in rescue medication use from week 1 of randomisation period compared to week 4 of randomisation period, between active and placebo arms
Measured: 4 weeks
Assessment of change breath methane levels during hydrogen and methane breath testing (HMBT)
Assessment of effect of active treatment vs placebo on breath hydrogen levels from baseline to end of randomised treatment period.
Breath hydrogen levels will be measured using a lactulose hydrogen and methane breath test. Total area under the curve for methane during the test will be calculated.
Measured: 4 weeks
Mean change irritable bowel syndrome quality of life (IBS-QoL) questionnaire score
Mean change IBS-QoL scores from baseline to end of randomised treatment period, between active and placebo groups.
The IBS-QoL questionnaire is made up of 34 questions each scored 1-5. Higher scores indicate better quality of life. Lower scores suggest more severe impact of IBS on daily living.
Measured: 4 weeks
Longevity of treatment effect
Longevity of treatment effect assessed in the active group with comparison of IBS-SSS scores from the randomised treatment period to end of open label period.
The IBS-SSS is numeric score based on 5 questions (each rated 0-100), with a total minimum score of 0 and maximum of 500, with a higher score indicating greater severity of symptoms.
Measured: 8 weeks
Stool Consistency
Stool Consistency assessed as average number of days with Bristol Stool Scale type (mean over 4 weeks, mean of first week and last week of the randomisation period).
A favorable change in mean score would be changes from type 6 or 7 stools (diarrhoea type stool consistency) to type 3,4,5 stools, which are considered normal stool consistency.
Measured: 4 weeks
Stool frequency
Stool Frequency (mean of 4 weeks, mean of first week and last week of the randomisation period)
Measured: 4 weeks
Change in bloating measured using daily bowel diary.
Change in average daily bloating score for week 1 of the randomised treatment period to week 4 of the randomised treatment period.
Severity of bloating will be scored daily by participants on a scale of 0-3, 0 being no bloating, 3 being severe bloating.
Measured: 4 weeks
Change in abdominal pain measured using the daily bowel diary
Change in average daily abdominal pain score for week 1 of the randomised treatment period to week 4 of the randomised treatment period.
Severity of abdominal pain will be scored daily by participants on a scale of 0-3, 0 being no bloating, 3 being severe bloating.
Measured: 4 weeks
Breath Hydrogen levels measured using hydrogen and methane breath testing (HMBT)
Assessment of effect of active treatment vs placebo on breath hydrogen levels from baseline to end of randomised treatment period.
Breath hydrogen levels will be measured using a lactulose hydrogen and methane breath test. Total area under the curve for hydrogen during the test will be calculated.
Measured: 4 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jul 2025
- Study start19 Sep 2024
- Primary completion8 Dec 2025
- Study completion30 Jan 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Irritable Bowel Syndrome (IBS)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
- Randomised
- Intervention model
- Parallel groups
- Model description
- The study will utilise a double blind design with 1:1 active to placebo, with crossover to open label treatment. The study comprises of a 2 week screening period followed by a 4 week randomised treatment period. At the end of the randomisation treatment period, participants will all receive active treatment open label for a further 4 weeks.
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 78 participants (actual)
Sponsor and investigators
- Lead sponsor
- Dr Anthony Hobson
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Dr Anthony Hobson, The Functional Gut Clinic
- Investigators
- Anthony Hobson, PhD, Principal investigator, The Functional Gut Clinic
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07052890
- Sponsor's protocol ID
- FGC-24-002
- Status last verified
- Mar 2026
- First submitted
- 10 Jun 2025
- Last updated
- 11 Mar 2026
- Results posted
- No
- Data monitoring committee
- 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 11 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Role of a Food Supplement Containing Curcumin, Green Tea and Vitamin D on Symptom Control in Diarrhoea Predominant Irritable Bowel Syndrome (IBS-D)
- ClinicalTrials.gov ID
- NCT07052890
- Acronym / sponsor ID
- FGC-24-002
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 78 participants (actual)
- Lead sponsor
- Dr Anthony HobsonUniversity, hospital or other
- Study start
- 19 Sep 2024 (actual)
- Primary completion
- 8 Dec 2025 (actual)
- Study completion
- 30 Jan 2026 (actual)
- First posted
- 8 Jul 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.
Irritable Bowel Syndrome (IBS) is a highly prevalent condition of the gastrointestinal tract that has significant impact on sufferer's quality of life. The diarrhoea variant (IBS-D) makes up around one third of all IBS sufferers. There is currently a lack of both effective pharmacological and non-pharmacological treatments for IBS-D.
Three food supplements: Green tea, vitamin D and curcumin have all been shown to demonstrate benefit in either reducing symptoms in IBS or diarrhoea as individual ingredients, but have never been tested in combination to assess their effectiveness in IBS. This research study aims to examine the effectiveness of green tea, vitamin D and curcumin in combination compared to a placebo capsule in individual suffering from IBS-D.
The study will aim to enroll 78 participants with IBS-D and utilise a placebo-controlled double blind design. The study will consist of a 2 week screening period, a 4 week randomised treatment period (50% participants to receive placebo, 50% to receive active treatment), followed by a 4 week open label treatment period (all participants to receive the active study product).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- The study will utilise a double blind design with 1:1 active to placebo, with crossover to open label treatment. The study comprises of a 2 week screening period followed by a 4 week randomised treatment period. At the end of the randomisation treatment period, participants will all receive active treatment open label for a further 4 weeks.
| Arm | Type | Receives |
|---|---|---|
| Placebo | Placebo comparator | Dietary Supplement: Placebo Capsule(s)28 days placebo capsules 4x daily, followed by 28 days of open label active treatment |
| Curcumin, Vitamin D and Green tea | Experimental | Dietary Supplement: Curcumin, vitamin d and green tea extract, Dietary Supplement: Placebo Capsule(s)28 days Curcumin, Vitamin D and Green tea capsules 4x daily, followed by a further 28 days of this treatment but non-blinded (open label) |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- Participant has provided written informed consent before participating in the study after being given a full description of the study and prior to any study-specific procedures being performed.
- Participant has irritable bowel syndrome with diarrhoea (IBS-D), as defined by the Rome IV criteria.
- Participant has an IBS-SSS score of >175 at screening.
- Participant is a male or non-pregnant female and is ≥18 years of age
- Participant can communicate well with the Investigator and to comply with the requirements for the entire study.
Key exclusion criteria (19 listed)
- Prior abdominal surgery other than appendectomy and cholecystectomy.
- Known hypercalcaemia.
- Participating in another trial or taken an IMP within the last 1 month.
- Females who report to be pregnant or lactating
- Unwilling to maintain stable doses of permitted concomitant medication
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 |
|---|---|---|
| Curcumin, vitamin d and green tea extractA combination of the following ingrediants per 4 capsules: CurcuWin® 1000mg - of which 200mg Curcuminoids Green Tea Extract 400mg - (0.1-0.5% caffeine) Vitamin D₃ 50 µg 2000IU | Dietary supplement | Curcumin, Vitamin D and Green tea |
| Placebo Capsule(s)Placebo - identical capsules containing inert color matched power | Dietary supplement | Curcumin, Vitamin D and Green tea, Placebo |
Primary outcome
Mean decrease of Irritable bowel syndrome symptom severity score (IBS-SSS)
Time frame: From Enrollment to end of 4 week randomised treatment period
Mean change in IBS-SSS at the end of the randomised treatment phase between Active and placebo arms. The IBS-SSS is numeric score based on 5 questions (each rated 0-100), with a total minimum score of 0 and maximum of 500, with a higher score indicating greater severity of symptoms.
9 secondary outcomes
Use of rescue medication
Time frame: 4 weeks
Assessment of change breath methane levels during hydrogen and methane breath testing (HMBT)
Time frame: 4 weeks
Mean change irritable bowel syndrome quality of life (IBS-QoL) questionnaire score
Time frame: 4 weeks
Longevity of treatment effect
Time frame: 8 weeks
Stool Consistency
Time frame: 4 weeks
Stool frequency
Time frame: 4 weeks
Change in bloating measured using daily bowel diary.
Time frame: 4 weeks
Change in abdominal pain measured using the daily bowel diary
Time frame: 4 weeks
Breath Hydrogen levels measured using hydrogen and methane breath testing (HMBT)
Time frame: 4 weeks
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 11 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.
Anthony Hobson, PhD principal investigator
The Functional Gut Clinic
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Curcumin, vitamin d and green tea extract in people with Irritable Bowel Syndrome (IBS) and Irritable Bowel Syndrome With Diarrhea (IBS-D), run by Dr Anthony Hobson at 3 sites 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 8 inclusion and 19 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 11 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 3 sites 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. Some participants in this study may receive a placebo. 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?
Mean decrease of Irritable bowel syndrome symptom severity score (IBS-SSS) (time frame: From Enrollment to end of 4 week randomised treatment period). 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 11 Mar 2026.