PreDiabetesNCT05628584
High FODMAP Diet With Metformin in preDM
A study testing High FODMAP diet with metformin and Low FODMAP diet with metformin in people with PreDiabetes and Impaired Glucose Tolerance, run by Elaine Chow at 1 site in Hong Kong.
Trial summary
This is a prospective, double blinded, randomised cross over feeding trial examine high or low FODMAP diet in combination with metformin on postprandial glucose responses and gastrointestinal tolerability and gut microbiota profiles. Read more about this study
- Who is it for?
- Ages 18 to 70 years
- Conditions the study is for
- PreDiabetes, Impaired Glucose Tolerance
- What is being tested?
- High FODMAP diet with metformin and Low FODMAP diet with metformin
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 26 participants
- Where
- 1 siteHong Kong
- Study dates
- 11 Nov 2022to 15 Oct 2023
- 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 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age 18-70 years
- Body mass index 18 to 40 kg/m 2
- Prediabetes defined as impaired fasting PG 5.6-6.9 mmol/l and/or impaired glucose tolerance with 2-hour PG 7.8-11.1 mmol/l on 75g oral glucose tolerance test (OGTT) and/or HbA1c 5.7-6.4% at screening
Who cannot join
- Currently pregnant, lactating, as demonstrated by a positive pregnancy test at screening or planning pregnancy
- Known current diabetes
- Current or previous use of glucose-lowering or weight loss drugs in 3 months prior to screening
- Concurrent participation in other weight loss or lifestyle intervention programmes
- Current use or recent exposure to any medication that in the opinion of the investigator could have an influence on the patient's ability to participate in this study or on the performance of the test device.
- Recent intake of prebiotic/probiotic or antibiotic, immunosuppressants (within 8 weeks of randomisation)
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- Extensive skin changes/diseases that preclude wearing the FGM on normal skin at the proposed application sites (e.g., extensive psoriasis, recent burns or severe sunburn, extensive eczema, extensive scarring, extensive tattoos, dermatitis herpetiformis).
- Known uncontrolled thyrotoxicosis
- Known vitamin B deficiency
- Known irritable bowel syndrome or gastrointestinal disorders
- Estimated glomerular filtration rate (eGFR) <45 ml/min/1.73m2 at screening
- Current use of steroids
- Have a known allergy to medical-grade adhesives
- Known current or recent alcohol or drug abuse
- Hypersensitivity to metformin
- Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma within 3 months of randomisation
- Currently participating in another investigational study protocol where the testing or results may interfere with study compliance, diagnostic results, or data collection.
- An identified protected vulnerable patient (including but not limited to those in detention, or a prisoner).
- Participants who are on a vegetarian or vegan diet as their habitual diet at screening.
- Participants with clinically significant food allergy to components of the study diet
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Impact of High or Low FODMAP Diets on Postprandial Glucose Response and Gut Microbiota in Individuals With Prediabetes Treated With Metformin: A Randomized Crossover Controlled-Feeding Trial
This is a prospective, double blinded, randomised cross over feeding trial examine high or low FODMAP diet in combination with metformin on postprandial glucose responses and gastrointestinal tolerability and gut microbiota profiles.
The trial will compare high or low FODMAP diet, each of 10 days duration in combination with 5 days metformin, separated by a washout period of at least 2 weeks.
- Conditions
- PreDiabetes, Impaired Glucose Tolerance
- Being tested
- High FODMAP diet with metformin, Low FODMAP diet with metformin
- Medical subject headings
- Prediabetic State, Glucose Intolerance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High FODMAP diet with metforminCombination product
Controlled High FODMAP diet (15g/day) from day 1-10, metformin XR 1000mg daily day 6-10 for each treatment period
Low FODMAP diet with metforminCombination product
Controlled low FODMAP diet (3g/day) from day 1-10, metformin XR 1000mg daily day 6-10 for each treatment period
| Study group | Role | What they receive |
|---|---|---|
| High FODMAP | Experimental | Not described Receives: Combination Product: High FODMAP diet with metformin |
| LOW FODMAP | Placebo comparator | Not described Receives: Combination Product: Low FODMAP diet with metformin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Differences in postprandial glycemia
incremental area under curve on continuous glucose monitoring post meal
Measured: 10 days
Secondary outcomes (6)
Glucose response to 75g oral glucose tolerance test
fasting and postchallenge plasma glucose
Measured: 10 days
Insulin response to 75g oral glucose tolerance test
insulin levels
Measured: 10 days
Change in alpha diversity of gut microbiota
Changes in alpha diversity in gut microbiota
Measured: 10 days
Change in beta diversity of gut microbiota
Changes in beta diversity in gut microbiota
Measured: 10 days
Body weight
Differences in body weight between arms
Measured: 10 days
Gastrointestinal symptoms
Measured on visual analogue scale 1-10 for each item, higher score indicates worse symptoms
Measured: 10 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Nov 2022
- Study start11 Nov 2022
- Primary completion25 Aug 2023
- Study completion15 Oct 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for PreDiabetesStudies 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 26 participants (actual)
Sponsor and investigators
- Lead sponsor
- Elaine Chow
- Sponsor type
- University, hospital or other
- Collaborators
- Merck KGaA, Darmstadt, Germany
- Responsible party
- Sponsor-investigator, Elaine Chow, Chinese University of Hong Kong
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05628584
- Sponsor's protocol ID
- FODMAPMet
- Status last verified
- Nov 2022
- First submitted
- 8 Nov 2022
- Last updated
- 5 Mar 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Chu NHS, Ling J, Poon EWM, Lee JYS, Song Q, Zuo Z, Muir J, Chan JCN, Chow E. Combining a diet rich in fermentable carbohydrates with metformin improves glycaemic control and reshapes the gut microbiota in people with prediabetes. Nat Metab. 2025 Aug;7(8):1614-1629. doi: 10.1038/s42255-025-01336-4. Epub 2025 Jul 31.
PubMed 40745466
Study at a glance
From the registry record, last updated by the sponsor on 5 Mar 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Impact of High or Low FODMAP Diets on Postprandial Glucose Response and Gut Microbiota in Individuals With Prediabetes Treated With Metformin: A Randomized Crossover Controlled-Feeding Trial
- ClinicalTrials.gov ID
- NCT05628584
- Acronym / sponsor ID
- FODMAPMet
- Conditions
- PreDiabetes, Impaired Glucose Tolerance
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 26 participants (actual)
- Lead sponsor
- Elaine ChowUniversity, hospital or other
- Collaborators
- Merck KGaA, Darmstadt, Germany
- Study start
- 11 Nov 2022 (actual)
- Primary completion
- 25 Aug 2023 (actual)
- Study completion
- 15 Oct 2023 (actual)
- First posted
- 28 Nov 2022 (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 is a prospective, double blinded, randomised cross over feeding trial examine high or low FODMAP diet in combination with metformin on postprandial glucose responses and gastrointestinal tolerability and gut microbiota profiles.
The trial will compare high or low FODMAP diet, each of 10 days duration in combination with 5 days metformin, separated by a washout period of at least 2 weeks.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| High FODMAP | Experimental | Combination Product: High FODMAP diet with metformin |
| LOW FODMAP | Placebo comparator | Combination Product: Low FODMAP diet with metformin |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Age 18-70 years
- Body mass index 18 to 40 kg/m 2
- Prediabetes defined as impaired fasting PG 5.6-6.9 mmol/l and/or impaired glucose tolerance with 2-hour PG 7.8-11.1 mmol/l on 75g oral glucose tolerance test (OGTT) and/or HbA1c 5.7-6.4% at screening
Key exclusion criteria (20 listed)
- Currently pregnant, lactating, as demonstrated by a positive pregnancy test at screening or planning pregnancy
- Known current diabetes
- Current or previous use of glucose-lowering or weight loss drugs in 3 months prior to screening
- Concurrent participation in other weight loss or lifestyle intervention programmes
- Current use or recent exposure to any medication that in the opinion of the investigator could have an influence on the patient's ability to participate in this study or on the performance of the test device.
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 |
|---|---|---|
| High FODMAP diet with metforminControlled High FODMAP diet (15g/day) from day 1-10, metformin XR 1000mg daily day 6-10 for each treatment period | Combination product | High FODMAP |
| Low FODMAP diet with metforminControlled low FODMAP diet (3g/day) from day 1-10, metformin XR 1000mg daily day 6-10 for each treatment period | Combination product | LOW FODMAP |
Primary outcome
Differences in postprandial glycemia
Time frame: 10 days
incremental area under curve on continuous glucose monitoring post meal
6 secondary outcomes
Glucose response to 75g oral glucose tolerance test
Time frame: 10 days
Insulin response to 75g oral glucose tolerance test
Time frame: 10 days
Change in alpha diversity of gut microbiota
Time frame: 10 days
Change in beta diversity of gut microbiota
Time frame: 10 days
Body weight
Time frame: 10 days
Gastrointestinal symptoms
Time frame: 10 days
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 2025.
- Derived from this study: PubMed 40745466Chu NHS, Ling J, Poon EWM, Lee JYS, Song Q, Zuo Z, Muir J, Chan JCN, Chow E. Combining a diet rich in fermentable carbohydrates with metformin improves glycaemic control and reshapes the gut microbiota in people with prediabetes. Nat Metab. 2025 Aug;7(8):1614-1629. doi: 10.1038/s42255-025-01336-4. Epub 2025 Jul 31.
- 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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing High FODMAP diet with metformin and Low FODMAP diet with metformin in people with PreDiabetes and Impaired Glucose Tolerance, run by Elaine Chow at 1 site in Hong Kong.
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 3 inclusion and 20 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 2025. 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 Hong Kong. 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?
Differences in postprandial glycemia (time frame: 10 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05628584, which also lists 1 linked publication.
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 2025.