Crohn's Disease in RemissionNCT05849012
A Pilot Study Examining Low Sulfur Diet as Treatment for Persistent Symptoms in Quiescent Crohn's Disease
A study testing Low Sulfur Diet and Usual Diet in people with Crohn's Disease in Remission, run by University of Michigan at 1 site in United States.
Trial summary
The goal of this study is to learn about a low sulfur diet in patients with Crohn's disease. Study participants will be randomized to receive a low sulfur diet or usual diet for 8 weeks. Participants will work with study nutritionists and receive dietary educational materials. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Crohn's Disease in Remission
- What is being tested?
- Low Sulfur Diet and Usual Diet
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 12 Dec 2023to 30 Apr 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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
- Prior diagnosis of Crohn's disease based on endoscopic, radiographic, and/or histologic findings
- Quiescent Crohn's disease as defined by fecal calprotectin level less than 150 micrograms/gram (mcg/g) stool and/or absence of inflammation on colonoscopy within 30 and 90 days, respectively, of enrollment
- Persistent symptoms will be defined by abdominal pain and/or diarrhea T-scores greater than or equal to 55 by the National Institutes of Health (NIH) Patient-Reported outcomes measurement information system Gastrointestinal scale (PROMIS-GI)
Who cannot join
- Prior total colectomy
- Presence of an end ileostomy or colostomy in place
- Changes in immunosuppressive medications within the past 4 weeks
- Use of antibiotics or probiotics within the past 4 weeks
- Active or suspected stricture/stenosis of the GI tract
- Habitual vegetarian or vegan diet
Show all 11Show fewer
- Active or suspected gastrointestinal stricture or stenosis
- Unable or unwilling to follow a low sulfur diet
- Patients who are underweight as defined by BMI < 18.5 kg/m2 or have significant unintentional weight loss as defined by >7.5% body weight in the past 3 months
- Currently pregnant, breastfeeding, and/or unwillingness/inability to use contraception start of the study until the last 13C-mannitol:lactulose test is complete. Sexually active male participants and/or their female partners of reproductive potential must agree to use effective contraception from the start of the study and until the last 13C-mannitol:lactulose test is complete. Women who are breastfeeding must stop breastfeeding during and for at least 12 hours after consuming the 13C-mannitol:lactulose test. Breastfeeding women must pump and dispose of the breastmilk during this time period
- Subjects must agree to not donate sperm or ova (eggs) or breast milk from the start of the study until the last 13C-mannitol:lactulose test is complete.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Merrick Bay contact
United States1 site, 1 recruiting
- Recruiting
University of Michigan
Ann Arbor, Michigan, 48109
Allen Lee, MD, MS, 734-936-9454, allenlee@umich.edu
Allen Lee, MD
About this study
The goal of this study is to learn about a low sulfur diet in patients with Crohn's disease. Study participants will be randomized to receive a low sulfur diet or usual diet for 8 weeks. Participants will work with study nutritionists and receive dietary educational materials. Participants will attend 2 in-person visits as well as 6 phone visits during the study. In addition, subjects will undergo testing, including a test to measure rectal sensation, a test to look for small intestinal bacterial overgrowth, and a test to measure leaky gut.
Read the detailed description
Even in the absence of active inflammation, persistent symptoms are reported in up to 46% of inflammatory bowel disease (IBD) patients, especially in Crohn's disease (CD). While persistent symptoms in quiescent Crohn's disease result in worsened quality of life and worse outcomes, evidence-based treatments do not currently exist due to lack of mechanistic understanding of this condition. The gut microbiome, which are the microbes that live in our gut, have been suggested as a potential cause of persistent symptoms. Diet is a major influence on the microbiome and may have a modifiable impact on persistent symptoms in Crohn's disease. However, this has not been well established.
The investigators propose a study period of approximately 8 weeks to evaluate the effects of a low sulfur diet in Crohn's disease. Participants will have an initial phone visit to determine eligibility to participate in the study and to review potential participants normal diet with a study nutritionist.
The treatment phase of 8 weeks will begin at the baseline visit (week 0). Participants will be randomized to receive a low sulfur diet or usual diet for 8 weeks. Participants on the low sulfur diet will meet with the study nutritionist to receive educational materials and recipes for the low sulfur diet. During this visit, participants will undergo testing, including a rectal barostat test to evaluate rectal sensation, glucose hydrogen breath test to assess for small intestinal bacterial overgrowth, lactulose-mannitol test to evaluate intestinal permeability, and a 24-hour urine sample to measure urine sulfate levels. Participants will be asked to collect saliva, serum, and stool samples.
Participants will then have phone visits every 2 weeks (week 2, week, 4, and week 6). Study nutritionists will monitor their dietary history and answer questions about the low sulfur diet if applicable.
At the conclusion of the 8 weeks, participants will have a final in-person study visit where rectal barostat, glucose hydrogen breath test, lactulose mannitol testing, and 24-hour urine sulfate level will be repeated. Stool and serum samples will be collected by participants.
Optional Low Sulfur Diet for participants randomized to the usual diet:
At the conclusion of the study (week 8), if participants randomized to usual diet are interested, will be offered treatment with a low sulfur diet for the next 8 weeks. Participants will meet with the study nutritionist that will provide educational materials on a low sulfur diet. Participants will have phone visits every 2 weeks (week 10, week 12, and week 14) to review dietary history and answer questions about the low sulfur diet. At the conclusion of the 16 weeks, participants will have a final in-person study visit where they will undergo testing, including a rectal barostat test to evaluate rectal sensation, glucose hydrogen breath test to assess for small intestinal bacterial overgrowth, lactulose-mannitol test to evaluate intestinal permeability, and a 24-hour urine sample to measure urine sulfate levels. Participants will be asked to collect saliva, serum, and stool samples.
- Conditions
- Crohn's Disease in Remission
- Being tested
- Low Sulfur Diet, Usual Diet
- Keywords
- Crohn's disease, Quiescent Crohn's disease, Low sulfur diet, Microbiome
- Medical subject headings
- Crohn Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Low Sulfur DietOther
Subjects will be placed on a low sulfur diet for 8 weeks with the support of a nutritionist.
In addition, participants will be asked to complete: surveys, lactulose-mannitol test, glucose hydrogen breath test, blood samples, visceral sensation test, 24-hour urine sample for sulfate level, provide stool samples, optional colonoscopy.
Usual DietOther
Subjects will continue on their usual diet for 8 weeks. At the end of 8 weeks, if participants are interested, they will be offered treatment with low sulfur diet for 8 weeks with the support of a nutritionist.
In addition, participants will be asked to complete: surveys, lactulose-mannitol test, glucose hydrogen breath test, blood samples, visceral sensation test, 24-hour urine sample for sulfate level, provide stool samples, optional colonoscopy.
| Study group | Role | What they receive |
|---|---|---|
| Low Sulfur Diet | Experimental | Participants in this group will follow a low sulfur diet. This diet decreases the amount of animal products (including meat, dairy, and eggs) as well as sulfur additives in the diet. The main types of foods in the low sulfur diet include fruits, vegetables, whole grains, nuts, seeds, and soy products. Receives: Other: Low Sulfur Diet |
| Usual Diet | Active comparator | Participants in this group will follow a standard of care usual diet for 8 weeks. Receives: Other: Usual Diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Dietary Protein Intake for both groups as assessed by 24 hour diet recall
Dietary protein intake (animal-based) as assessed by 24 hour diet recall
Measured: 8 weeks
Dietary Protein Intake as assessed by 24 hour diet recall
Dietary protein intake (animal-based) as assessed by 24 hour diet recall. This is for the group that voluntarily goes on the low sulfur diet after standard of care arm is completed.
Measured: Approximately 16 weeks
Change in 24 hour urinary sulfate
Change in 24 hour urinary sulfate level from baseline
Measured: 8 weeks
Change in 24 hour urinary sulfate
Change in 24 hour urinary sulfate level from baseline. This is for the group that voluntarily goes on the low sulfur diet after standard of care arm is completed
Measured: Approximately 16 weeks
Secondary outcomes (4)
Tolerability of Low Sulfur Diet based on the Visual Analog Scale (VAS)
The VAS has 5 questions in which participants are asked about knowledge, purchase, preparation, ease of following the diet, and overall tolerability of the sulfur diet. Each question participants will score between 0-100 (higher score is more tolerable with total points of 500).
Measured: Week 4
Tolerability of Low Sulfur Diet based on the Visual Analog Scale (VAS)
The VAS has 5 questions in which participants are asked about knowledge, purchase, preparation, ease of following the diet, and overall tolerability of the sulfur diet. Each question participants will score between 0-100 (higher score is more tolerable with total points of 500). This is for the group that voluntarily goes on the low sulfur diet after standard of care arm is completed.
Measured: Approximately week 12
Tolerability of Low Sulfur Diet based on the Visual Analog Scale (VAS)
The VAS has 5 questions in which participants are asked about knowledge, purchase, preparation, ease of following the diet, and overall tolerability of the sulfur diet. Each question participants will score between 0-100 (higher score is more tolerable with total points of 500).
Measured: Week 8
Tolerability of Low Sulfur Diet based on the Visual Analog Scale (VAS)
The VAS has 5 questions in which participants are asked about knowledge, purchase, preparation, ease of following the diet, and overall tolerability of the sulfur diet. Each question participants will score between 0-100 (higher score is more tolerable with total points of 500). This is for the group that voluntarily goes on the low sulfur diet after standard of care arm is completed.
Measured: Approximately 16 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 May 2023
- Study start12 Dec 2023
- Primary completion30 Dec 2026 (estimated)
- Study completion30 Apr 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Crohn's Disease in RemissionStudies of the same condition, open and under way.
- More trials run by University of MichiganThe sponsor's other registered studies.
- 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
- 20 subjects will be randomized to receive either a low sulfur diet or usual diet.
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Michigan
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Allen Lee, University of Michigan
- Investigators
- Allen Lee, MD, MS, Principal investigator, Assistant Professor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05849012
- Sponsor's protocol ID
- HUM00218796
- Status last verified
- Jan 2026
- First submitted
- 25 Apr 2023
- Last updated
- 15 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: To be determined
Study at a glance
From the registry record, last updated by the sponsor on 15 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Pilot Study Examining Low Sulfur Diet as Treatment for Persistent Symptoms in Quiescent Crohn's Disease
- ClinicalTrials.gov ID
- NCT05849012
- Acronym / sponsor ID
- HUM00218796
- Conditions
- Crohn's Disease in Remission
- Keywords
- Crohn's disease, Quiescent Crohn's disease, Low sulfur diet, Microbiome
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- University of MichiganUniversity, hospital or other
- Study start
- 12 Dec 2023 (actual)
- Primary completion
- 30 Dec 2026 (estimated)
- Study completion
- 30 Apr 2027 (estimated)
- First posted
- 8 May 2023 (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.
The goal of this study is to learn about a low sulfur diet in patients with Crohn's disease. Study participants will be randomized to receive a low sulfur diet or usual diet for 8 weeks. Participants will work with study nutritionists and receive dietary educational materials. Participants will attend 2 in-person visits as well as 6 phone visits during the study. In addition, subjects will undergo testing, including a test to measure rectal sensation, a test to look for small intestinal bacterial overgrowth, and a test to measure leaky gut.
Detailed description
Even in the absence of active inflammation, persistent symptoms are reported in up to 46% of inflammatory bowel disease (IBD) patients, especially in Crohn's disease (CD). While persistent symptoms in quiescent Crohn's disease result in worsened quality of life and worse outcomes, evidence-based treatments do not currently exist due to lack of mechanistic understanding of this condition. The gut microbiome, which are the microbes that live in our gut, have been suggested as a potential cause of persistent symptoms. Diet is a major influence on the microbiome and may have a modifiable impact on persistent symptoms in Crohn's disease. However, this has not been well established.
The investigators propose a study period of approximately 8 weeks to evaluate the effects of a low sulfur diet in Crohn's disease. Participants will have an initial phone visit to determine eligibility to participate in the study and to review potential participants normal diet with a study nutritionist.
The treatment phase of 8 weeks will begin at the baseline visit (week 0). Participants will be randomized to receive a low sulfur diet or usual diet for 8 weeks. Participants on the low sulfur diet will meet with the study nutritionist to receive educational materials and recipes for the low sulfur diet. During this visit, participants will undergo testing, including a rectal barostat test to evaluate rectal sensation, glucose hydrogen breath test to assess for small intestinal bacterial overgrowth, lactulose-mannitol test to evaluate intestinal permeability, and a 24-hour urine sample to measure urine sulfate levels. Participants will be asked to collect saliva, serum, and stool samples.
Participants will then have phone visits every 2 weeks (week 2, week, 4, and week 6). Study nutritionists will monitor their dietary history and answer questions about the low sulfur diet if applicable.
At the conclusion of the 8 weeks, participants will have a final in-person study visit where rectal barostat, glucose hydrogen breath test, lactulose mannitol testing, and 24-hour urine sulfate level will be repeated. Stool and serum samples will be collected by participants.
Optional Low Sulfur Diet for participants randomized to the usual diet:
At the conclusion of the study (week 8), if participants randomized to usual diet are interested, will be offered treatment with a low sulfur diet for the next 8 weeks. Participants will meet with the study nutritionist that will provide educational materials on a low sulfur diet. Participants will have phone visits every 2 weeks (week 10, week 12, and week 14) to review dietary history and answer questions about the low sulfur diet. At the conclusion of the 16 weeks, participants will have a final in-person study visit where they will undergo testing, including a rectal barostat test to evaluate rectal sensation, glucose hydrogen breath test to assess for small intestinal bacterial overgrowth, lactulose-mannitol test to evaluate intestinal permeability, and a 24-hour urine sample to measure urine sulfate levels. Participants will be asked to collect saliva, serum, and stool samples.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- 20 subjects will be randomized to receive either a low sulfur diet or usual diet.
| Arm | Type | Receives |
|---|---|---|
| Low Sulfur Diet | Experimental | Other: Low Sulfur DietParticipants in this group will follow a low sulfur diet. This diet decreases the amount of animal products (including meat, dairy, and eggs) as well as sulfur additives in the diet. The main types of foods in the low sulfur diet include fruits, vegetables, whole grains, nuts, seeds, and soy products. |
| Usual Diet | Active comparator | Other: Usual DietParticipants in this group will follow a standard of care usual diet for 8 weeks. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Prior diagnosis of Crohn's disease based on endoscopic, radiographic, and/or histologic findings
- Quiescent Crohn's disease as defined by fecal calprotectin level less than 150 micrograms/gram (mcg/g) stool and/or absence of inflammation on colonoscopy within 30 and 90 days, respectively, of enrollment
- Persistent symptoms will be defined by abdominal pain and/or diarrhea T-scores greater than or equal to 55 by the National Institutes of Health (NIH) Patient-Reported outcomes measurement information system Gastrointestinal scale (PROMIS-GI)
Key exclusion criteria (11 listed)
- Prior total colectomy
- Presence of an end ileostomy or colostomy in place
- Changes in immunosuppressive medications within the past 4 weeks
- Use of antibiotics or probiotics within the past 4 weeks
- Active or suspected stricture/stenosis of the GI tract
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 |
|---|---|---|
| Low Sulfur DietSubjects will be placed on a low sulfur diet for 8 weeks with the support of a nutritionist. In addition, participants will be asked to complete: surveys, lactulose-mannitol test, glucose hydrogen breath test, blood samples, visceral sensation test, 24-hour urine sample for sulfate level, provide stool samples, optional colonoscopy. | Other | Low Sulfur Diet |
| Usual DietSubjects will continue on their usual diet for 8 weeks. At the end of 8 weeks, if participants are interested, they will be offered treatment with low sulfur diet for 8 weeks with the support of a nutritionist. In addition, participants will be asked to complete: surveys, lactulose-mannitol test, glucose hydrogen breath test, blood samples, visceral sensation test, 24-hour urine sample for sulfate level, provide stool samples, optional colonoscopy. | Other | Usual Diet |
Primary outcome
Dietary Protein Intake for both groups as assessed by 24 hour diet recall
Time frame: 8 weeks
Dietary protein intake (animal-based) as assessed by 24 hour diet recall
Dietary Protein Intake as assessed by 24 hour diet recall
Time frame: Approximately 16 weeks
Dietary protein intake (animal-based) as assessed by 24 hour diet recall. This is for the group that voluntarily goes on the low sulfur diet after standard of care arm is completed.
Change in 24 hour urinary sulfate
Time frame: 8 weeks
Change in 24 hour urinary sulfate level from baseline
Change in 24 hour urinary sulfate
Time frame: Approximately 16 weeks
Change in 24 hour urinary sulfate level from baseline. This is for the group that voluntarily goes on the low sulfur diet after standard of care arm is completed
4 secondary outcomes
Tolerability of Low Sulfur Diet based on the Visual Analog Scale (VAS)
Time frame: Week 4
Tolerability of Low Sulfur Diet based on the Visual Analog Scale (VAS)
Time frame: Approximately week 12
Tolerability of Low Sulfur Diet based on the Visual Analog Scale (VAS)
Time frame: Week 8
Tolerability of Low Sulfur Diet based on the Visual Analog Scale (VAS)
Time frame: Approximately 16 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Jan 2026.
- Individual participant dataSharing planned: Yes. To be determined
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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.
Merrick Bay contact
Allen Lee, MD, MS principal investigator
Assistant Professor
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Low Sulfur Diet and Usual Diet in people with Crohn's Disease in Remission, run by University of Michigan at 1 site in United States.
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 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: looking for participants now, as of the sponsor's last update on 15 Jan 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 States. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Allen Lee, MD, MS (734-936-9454, allenlee@umich.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Dietary Protein Intake for both groups as assessed by 24 hour diet recall (time frame: 8 weeks). The study lists 4 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 15 Jan 2026; AzTrials last refreshed its copy on 6 Nov 2026.