NCT05849012 · University of Michigan
A Pilot Study Examining Low Sulfur Diet as Treatment for Persistent Symptoms in Quiescent Crohn's Disease
What this study is about
The goal of this study is to learn about a low sulfur diet in patients with Crohn's disease. Study participants will be randomly assigned 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.
View original scientific description
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.
Interventions
OTHER
Low Sulfur Diet
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.
OTHER
Usual Diet
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.
Primary outcome measures
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
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- 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)
Exclusion criteria
- 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
- 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.
Where
- Ann Arbor, Michigan
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Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
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Data: ClinicalTrials.gov · synced Jan 15, 2026 · Source of record for eligibility and locations