Iron Deficiency Anemia TreatmentNCT04705662
GI Effects of Iron in Healthy Volunteers
A study testing Lactulose breath test, Stool sample and Daily Diary in people with Iron Deficiency Anemia Treatment and Microbial Colonization, run by Dr Anthony Hobson at 2 sites in United Kingdom.
Trial summary
Over recent years there has been a lot of research looking at how the bacteria in our gut affects our health. Some medications are known to cause changes in gut bacteria. Many patients that are prescribed iron report gastrointestinal side effects. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Iron Deficiency Anemia Treatment, Microbial Colonization, Iron-deficiency
- What is being tested?
- Lactulose breath test, Stool sample and Daily Diary
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 48 participants
- Where
- 2 sitesUnited Kingdom
- Study dates
- 1 Mar 2021to 30 Jun 2022
- 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 60 years
- All sexes
- Healthy volunteers accepted
- 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 is a male or non-pregnant female (confirmed by pregnancy test) and is age 18 years to 60 years.
- 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 no significant medical diagnosis or current or previous chronic gastrointestinal disease requiring medication or surgery (apart from appendectomy). Participant has no disease that would contraindicate iron supplementation e.g. haemochromatosis.
- Participant is not on regular prescription medicines unless a stable dose for the past 6-months and duration of the trial.
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- Participant has a body mass index (BMI) of 18.5 - 34.9 kg/m2 (bounds included).
- Participant agrees to follow pre-test diet for 24 hours before giving test sample.
- Participant agrees to refrain from strenuous physical activity on the day of the breath test.
- Participant agrees to refrain from smoking on the day of the breath test.
- Participant agrees to an overnight fast on the night before the breath test. Food and drink must be withheld until after all breath test samples have been taken.
- Participant agrees to not take any probiotic for 14 days before the breath test or during the study.
- Participant has not taken antibiotics for 4-weeks before the start of the study or during the study
Who cannot join
- Participant has no significant medical diagnosis or current or previous chronic gastrointestinal disease requiring medication or surgery (apart from appendectomy). Participant has no disease that would contraindicate iron supplementation e.g. haemochromatosis.
- Participant is pregnant or breast feeding.
- Participant takes medication known to impact the gut microbiome:
- Antibiotics used in the last 4 weeks
- Regular use of laxatives or anti-diarrheal medication
- Participant is taking a regular prescription medication that has a contraindication with oral iron supplementation.
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- Participant has undergone a colonoscopy/sigmoidoscopy in the 1 week prior to enrolment.
- Participant regularly consumes probiotics, prebiotics, fibre supplements in the 4 weeks prior to enrolment and/or is unwilling to exclude the use of probiotics from the diet during the study period.
- Participant is involved in this study as an Investigator, sub-Investigator, study coordinator, other study staff, or sponsor member.
- Participant has had previous abdominal or colorectal surgery except appendectomy or hysterectomy.
- Participant has had oral iron supplementation of IV iron supplementation in the 12 months prior to enrolment.
Trial locations and contacts
2 sites in 1 country.
United Kingdom2 sites
The Functional Gut Clinic
Cambridge, Greater Manchester, M2 4NG
The Functional Gut Clinic
Manchester, Greater Manchester, M3 4BG
About this study
Official title: Investigating the Effects of Iron on the Gastrointestinal Tract in Health.
Over recent years there has been a lot of research looking at how the bacteria in our gut affects our health. Some medications are known to cause changes in gut bacteria.
Many patients that are prescribed iron report gastrointestinal side effects. This research project aims to see if the cause of the gastrointestinal side effects is due to iron causing changes in the gut bacteria. This can be detected via measuring the levels of hydrogen and methane and other compounds in the breath and stool.
Read the detailed description
Iron deficiency anaemia is the most common health issue worldwide, with approximately >1.2 billion people affected. In the UK, iron deficiency anaemia most commonly affects pre-school aged children and women aged 15-49 years. In 2011, an estimated 14% of non-pregnant, and 23% of pregnant women in the UK had iron deficiency anaemia, and 2-5% of male and post-menopausal women were also affected. Whilst compared to other areas of the world IDA has a mild public health significance to the UK, it can be the reason for up-to 13% of referrals to gastroenterologists.
Treating IDA with oral supplements or IV infusions are both effective at restoring bodily iron stores. However, success is often greater in those receiving their iron intravenously, due to frequent non-adherence to oral tablets as a result of their side effects. Gastrointestinal complaints, most commonly constipation, are reported by up to 60% of people that take oral iron supplements. These GI complaints causes up to 50% of patient to not follow their treatment plan, meaning their iron deficiency anaemia persists. However, patients that receive intravenous iron infusions instead do not report these symptoms. This suggests that oral iron has an impact on the GI tract as intravenous iron will bypass the gastrointestinal lumen but the mechanism of this remains uncertain.
To investigate the side effects of oral iron supplements and research a potential mechanism for the cause of iron supplement side effects, this study will require healthy volunteers to take ferrous sulphate for 4 weeks. Pre and post intervention participants will be required to provide a stool sample, complete a breath test and answer questionnaires.
- Conditions
- Iron Deficiency Anemia Treatment, Microbial Colonization, Iron-deficiency, Iron Deficiency Anemia
- Being tested
- Lactulose breath test, Stool sample, Daily Diary, Irritable Bowel syndrome severity scoring system (IBS-SSS) questionnaire, Ferrous Sulphate
- Keywords
- ferrous sulphate
- Medical subject headings
- Communicable Diseases, Anemia, Iron-Deficiency
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Lactulose breath testDiagnostic test
Participants will complete a 3 hour breath test pre and post iron supplementation. This will include taking 4 exploratory samples for volatile organic compound (VOC) analysis.
Stool sampleOther
Participants will provide a stool sample pre and post iron supplementation
Daily DiaryOther
Monitoring stool form, consistency and frequency on a daily basis
Irritable Bowel syndrome severity scoring system (IBS-SSS) questionnaireOther
Participants will complete the questionnaire pre and post iron supplementation
Ferrous SulphateDietary supplement
Participants will take Ferrous sulphate 200mg (65mg elemental iron) for 4 weeks (+/- 2 days). Participants will be required to take 2 tablets per day.
| Study group | Role | What they receive |
|---|---|---|
| Ferrous Sulphate | Other | This is a single arm study, all participants will take Ferrous sulphate 200mg (65mg elemental iron) for 4 weeks (+/- 2 days). Participants will be required to take 2 tablets per day. Receives: Diagnostic Test: Lactulose breath test; Other: Stool sample; Other: Daily Diary; Other: Irritable Bowel syndrome severity scoring system (IBS-SSS) questionnaire; Dietary Supplement: Ferrous Sulphate |
What is being measured
The primary outcome is the main question the study is designed to answer.
Breath methane levels
Difference in methane levels in breath samples from baseline and 4-weeks since commencing iron therapy. This will be measured in parts per million (ppm).
Measured: 4 weeks apart
Secondary outcomes (4)
Volatile organic compounds (VOC) in breath
Difference in any breath gas markers. This is exploratory so will look to see what is present at baseline and see how it changes over the 4 week study period.
Measured: 4 weeks apart
Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS)
Comparison in change of IBS-SSS score from baseline to 4 weeks since commencing iron therapy. The minimum score is 0 and maximum score is 500. The greater the score, the worse the severity and frequency of symptoms of abdominal pain and distention, and increased dissatisfaction of overall bowel functioning.
Measured: 4 weeks apart
Stool consistency via the Bristol Stool Chart
Change in stool frequency and form according to the bristol stool chart scale from baseline to 4 weeks since commencing iron therapy.
Measured: 4 weeks apart
Gut Microbiome analysis via stool samples
Qualitative and Quantitative data for faecal microorganisms at baseline and 4-weeks since commencing iron therapy.
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 posted12 Jan 2021
- Study start1 Mar 2021
- Primary completion30 Jun 2022
- Study completion30 Jun 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Iron Deficiency Anemia TreatmentStudies 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
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 48 participants (actual)
Sponsor and investigators
- Lead sponsor
- Dr Anthony Hobson
- Sponsor type
- University, hospital or other
- Collaborators
- Anglia Ruskin University
- Responsible party
- Sponsor-investigator, Dr Anthony Hobson, The Functional Gut Clinic
- Investigators
- Anthony Hobson, Study chair, The Functional Gut Clinic
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04705662
- Sponsor's protocol ID
- FGC-20-002
- Status last verified
- Apr 2025
- First submitted
- 5 Jan 2021
- Last updated
- 22 Apr 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Results will be written up and published in journal articles and presented at conferences
Study at a glance
From the registry record, last updated by the sponsor on 22 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigating the Effects of Iron on the Gastrointestinal Tract in Health.
- ClinicalTrials.gov ID
- NCT04705662
- Acronym / sponsor ID
- FGC-20-002
- Conditions
- Iron Deficiency Anemia Treatment, Microbial Colonization, Iron-deficiency, Iron Deficiency Anemia
- Keywords
- ferrous sulphate
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 48 participants (actual)
- Lead sponsor
- Dr Anthony HobsonUniversity, hospital or other
- Collaborators
- Anglia Ruskin University
- Study start
- 1 Mar 2021 (actual)
- Primary completion
- 30 Jun 2022 (actual)
- Study completion
- 30 Jun 2022 (actual)
- First posted
- 12 Jan 2021 (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.
Over recent years there has been a lot of research looking at how the bacteria in our gut affects our health. Some medications are known to cause changes in gut bacteria.
Many patients that are prescribed iron report gastrointestinal side effects. This research project aims to see if the cause of the gastrointestinal side effects is due to iron causing changes in the gut bacteria. This can be detected via measuring the levels of hydrogen and methane and other compounds in the breath and stool.
Detailed description
Iron deficiency anaemia is the most common health issue worldwide, with approximately >1.2 billion people affected. In the UK, iron deficiency anaemia most commonly affects pre-school aged children and women aged 15-49 years. In 2011, an estimated 14% of non-pregnant, and 23% of pregnant women in the UK had iron deficiency anaemia, and 2-5% of male and post-menopausal women were also affected. Whilst compared to other areas of the world IDA has a mild public health significance to the UK, it can be the reason for up-to 13% of referrals to gastroenterologists.
Treating IDA with oral supplements or IV infusions are both effective at restoring bodily iron stores. However, success is often greater in those receiving their iron intravenously, due to frequent non-adherence to oral tablets as a result of their side effects. Gastrointestinal complaints, most commonly constipation, are reported by up to 60% of people that take oral iron supplements. These GI complaints causes up to 50% of patient to not follow their treatment plan, meaning their iron deficiency anaemia persists. However, patients that receive intravenous iron infusions instead do not report these symptoms. This suggests that oral iron has an impact on the GI tract as intravenous iron will bypass the gastrointestinal lumen but the mechanism of this remains uncertain.
To investigate the side effects of oral iron supplements and research a potential mechanism for the cause of iron supplement side effects, this study will require healthy volunteers to take ferrous sulphate for 4 weeks. Pre and post intervention participants will be required to provide a stool sample, complete a breath test and answer questionnaires.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Ferrous Sulphate | Other | Diagnostic Test: Lactulose breath test, Other: Stool sample, Other: Daily Diary, Other: Irritable Bowel syndrome severity scoring system (IBS-SSS) questionnaire, Dietary Supplement: Ferrous SulphateThis is a single arm study, all participants will take Ferrous sulphate 200mg (65mg elemental iron) for 4 weeks (+/- 2 days). Participants will be required to take 2 tablets per day. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (13 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 is a male or non-pregnant female (confirmed by pregnancy test) and is age 18 years to 60 years.
- 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 no significant medical diagnosis or current or previous chronic gastrointestinal disease requiring medication or surgery (apart from appendectomy). Participant has no disease that would contraindicate iron supplementation e.g. haemochromatosis.
Key exclusion criteria (11 listed)
- Participant has no significant medical diagnosis or current or previous chronic gastrointestinal disease requiring medication or surgery (apart from appendectomy). Participant has no disease that would contraindicate iron supplementation e.g. haemochromatosis.
- Participant is pregnant or breast feeding.
- Participant takes medication known to impact the gut microbiome:
- Participant is taking a regular prescription medication that has a contraindication with oral iron supplementation.
- Participant has undergone a colonoscopy/sigmoidoscopy in the 1 week prior to enrolment.
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 |
|---|---|---|
| Lactulose breath testParticipants will complete a 3 hour breath test pre and post iron supplementation. This will include taking 4 exploratory samples for volatile organic compound (VOC) analysis. | Diagnostic test | Ferrous Sulphate |
| Stool sampleParticipants will provide a stool sample pre and post iron supplementation | Other | Ferrous Sulphate |
| Daily DiaryMonitoring stool form, consistency and frequency on a daily basis | Other | Ferrous Sulphate |
| Irritable Bowel syndrome severity scoring system (IBS-SSS) questionnaireParticipants will complete the questionnaire pre and post iron supplementation | Other | Ferrous Sulphate |
| Ferrous SulphateParticipants will take Ferrous sulphate 200mg (65mg elemental iron) for 4 weeks (+/- 2 days). Participants will be required to take 2 tablets per day. | Dietary supplement | Ferrous Sulphate |
Primary outcome
Breath methane levels
Time frame: 4 weeks apart
Difference in methane levels in breath samples from baseline and 4-weeks since commencing iron therapy. This will be measured in parts per million (ppm).
4 secondary outcomes
Volatile organic compounds (VOC) in breath
Time frame: 4 weeks apart
Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS)
Time frame: 4 weeks apart
Stool consistency via the Bristol Stool Chart
Time frame: 4 weeks apart
Gut Microbiome analysis via stool samples
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 22 Apr 2025.
- Individual participant dataSharing planned: No. Results will be written up and published in journal articles and presented at conferences
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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 study chair
The Functional Gut Clinic
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Lactulose breath test, Stool sample and Daily Diary in people with Iron Deficiency Anemia Treatment and Microbial Colonization, run by Dr Anthony Hobson at 2 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 13 inclusion and 11 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 22 Apr 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 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. 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?
Breath methane levels (time frame: 4 weeks apart). 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 22 Apr 2025.