Using Breath Tests to Study Gut Sulfur Changes During Dietary Therapy
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Elemental formula (mBiota Elemental, Good LFE, Santa Monica, CA), Reduced Sulfur diet, Habitual Diet.
- Who it may be relevant to
- Registry conditions: Ulcerative Colitis (UC). Basic parameters: 19 years — 70 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Canada
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Sulfur on the Breath: Using Breath Biomarkers to Monitor Gut Microbial Sulfur Metabolism During Elemental and Reduced Sulfur Dietary Therapy
Overview
This study aims to test whether a short liquid-based diet, followed by a low-sulfur eating plan, is safe, manageable, and helpful for people with mild to moderate ulcerative colitis. Investigators want to see if this approach can improve gut health, lower inflammation, and reduce symptoms. Investigators will also test breath samples as an easy, non-invasive way to track gut bacteria activity and disease changes. Investigators believe this diet plan can reduce harmful gut bacteria that produce irritating sulfur compounds, leading to better gut health and measurable improvements that can be detected through breath testing.
Detailed description
Purpose To determine whether a short-term elemental diet followed by a reduced sulfur diet is a safe, tolerable, and effective non-pharmacologic strategy to improve clinical outcomes, reduce inflammation, and beneficially modulate the gut microbiome in adults with mild-to-moderate ulcerative colitis. A secondary purpose is to validate breath-based biomarkers as non-invasive tools to monitor sulfur metabolism and disease activity. Breath biomarkers include volatile organic compounds (VOCs) and exhaled breath condensate (EBC) to assess sulfur-related metabolites.
Hypothesis A 2-week elemental diet followed by a 10-week reduced sulfur diet will reduce intestinal inflammation and improve clinical outcomes by shifting the gut microbiome away from pro-inflammatory, sulfur-metabolizing bacteria, resulting in reduced sulfur metabolite production detectable through exhaled volatile organic compounds and exhaled breath condensate.
Justification Despite advances in biologic therapies, many UC patients fail to achieve sustained remission, and current treatments do not address upstream drivers such as diet-microbiome interactions. Elemental diets have demonstrated efficacy in Crohn's disease but remain understudied in UC. Emerging evidence links dietary sulfur, microbial sulfur metabolism, and toxic metabolites to UC pathogenesis. This study addresses critical gaps by testing a feasible dietary intervention and validating non-invasive breath biomarkers for real-time disease monitoring and precision nutrition.
Objectives
* Evaluate the clinical efficacy, safety, and feasibility of an elemental diet followed by an reduced sulfur diet. * Characterize changes in gut microbiome composition, inflammatory markers, and sulfur-related metabolic outputs. * Validate breath-based volatile organic compounds and exhaled breath condensate as biomarkers of sulfur metabolism and treatment response. * Identify microbial and metabolic signatures predictive of dietary response.
Research Design A prospective, randomized, controlled trial in adults with mild-to-moderate UC. All participants complete a 2-week elemental diet, followed by randomization (2:1) to either a reduced sulfur diet group (intervention group) or return to habitual diet group (control group) for 10 weeks. Clinical indices, inflammatory biomarkers, stool microbiome profiles and breath samples are collected longitudinally. The initial 2-week elemental diet is applied uniformly to standardize baseline microbial and metabolic conditions prior to randomization and does not replace or delay clinical care decisions.
Statistical Analysis Primary outcomes will be assessed using within- and between-group comparisons of clinical and biochemical response at week 12. Microbiome and metabolomic data will be analyzed using multivariate and differential abundance methods. Correlations between breath biomarkers, microbiome features, and clinical outcomes will assess sensitivity and specificity.
Interventions
- Dietary supplement Elemental formula (mBiota Elemental, Good LFE, Santa Monica, CA)
Elemental liquid diets (EDs) are a subset of Exclusive Enteral Nutrition (EEN). Similar to EEN, they are nutritionally complete formulas, but differ in that they consist of free amino acids, monosaccharides, and fatty acids instead of whole, intact macronutrients, which are designed for optimal digestibility and to minimize antigenicity. EDs have been shown to reduce immune activation, favourably modulate the microbiota, suppress proinflammatory cytokines, support epithelial repair, and exclude - Behavioral Reduced Sulfur diet
This diet excludes high sulfur foods (e.g., red meat, seafood, eggs), cruciferous vegetables, dried fruits, and fermented beverages. It also accounts for sulfate intake from drinking water and processed food additives. - Behavioral Habitual Diet
Participants randomized to the comparator group will continue their usual dietary intake for 10 weeks without specific dietary restrictions.
Primary outcome measures
- Composite clinical and biochemical response [Time frame: Baseline, Week 2 and week 12]
Secondary outcome measures (11)
- Stool Biomarkers [Time frame: Baseline, week 2 and week 12]
- C-Reactive Protein (CRP) concentration [Time frame: Baseline, week 2 and week 12]
- Complete Blood Count (CBC) parameters [Time frame: Baseline, week 2 and week 12]
- Serum inflammatory biomarker concentrations [Time frame: Baseline, week 2 and week 12]
- Breath Biomarkers [Time frame: Baseline, week 2 and week 12]
- Adherence to the Elemental Diet and Reduced Sulfur Diet Intervention [Time frame: Baseline, week 2 and week 12]
- Change in Quality of Life [Time frame: Baseline, week 2 and week 12]
- Change in Anxiety [Time frame: Baseline, week 2 and week 12]
- Change in Depression [Time frame: Baseline, week 2 and week 12]
- Change in Weight [Time frame: Baseline, week 2 and week 12]
- Change in Body Mass Index (BMI) [Time frame: Baseline, week 2 and week 12]
Eligibility criteria
Inclusion criteria
- Age 19-70 years.
=Diagnosis of mild-to-moderate ulcerative colitis, defined by a partial Mayo score (pMayo) of 2-7.
- Evidence of active inflammation at enrollment, defined as:
- C-reactive protein (CRP) > 5 mg/L; or
- Fecal calprotectin (FCP) > 200 µg/g.
- Receiving stable medical therapy for ulcerative colitis for at least 8 weeks prior to enrollment.
- No corticosteroid use at the time of recruitment.
- Under consideration by the treating physician for treatment escalation or biologic switch due to inadequate response to current therapy.
Exclusion criteria
- Partial Mayo score (pMayo) > 7.
- Pregnant or breastfeeding.
- Body mass index (BMI) < 18 kg/m².
- History of an eating disorder.
- Severe psychiatric disorder.
- Severe medical conditions, including:
- Active cancer;
- Significant cardiovascular disease;
- Diabetes mellitus; or
- Severe food allergies.
- Known allergy or intolerance to corn, dextrose, or maltodextrin.
- Antibiotic use within 3 months prior to enrollment.
- Probiotic use within 3 months prior to enrollment.
- Use of herbal anti-inflammatory supplements during the study period, including but not limited to:
- Serrapeptidase;
- Curcumin;
- Boswellia; or
- Bromelain.
- History of major gastrointestinal surgery, including:
- Ostomy;
- Total colectomy; or
- Short bowel syndrome.
- Inability or unwillingness to comply with study procedures, including anticipated travel or other commitments that may interfere with participation.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Single blind
- Primary purpose
- Treatment
Study locations
Canada · 1 center
- University of British Columbia-Okanagan — Kelowna
Identifiers
NCT: NCT07640659 · H26-00017 · POP25-11968