Using Breath Tests to Study Gut Sulfur Changes During Dietary Therapy

NCT07640659 | Not Yet Recruiting DMC

• 2 other identifiers: H26-00017POP25-11968
• Study Type: interventional
• Target: 45
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Ulcerative Colitis (UC)

Keywords

Ulcerative colitis

Outcome Measures

Primary Outcomes (1)

• Composite clinical and biochemical response

  Composite clinical and biochemical response at week 12, defined as \>30% and \>1-point reduction in pMayo score from baseline, plus rectal bleeding subscore decrease of \>1 or an absolute subscore \<1, with fecal calprotectin \<250 μg/g and CRP \<5 mg/L.

  Baseline, Week 2 and week 12

Secondary Outcomes (11)

• Stool Biomarkers

  Baseline, week 2 and week 12

• C-Reactive Protein (CRP) concentration

  Baseline, week 2 and week 12

• Complete Blood Count (CBC) parameters

  Baseline, week 2 and week 12

• Serum inflammatory biomarker concentrations

  Baseline, week 2 and week 12

• Breath Biomarkers

  Baseline, week 2 and week 12

Study Arms (2)

Reduced Sulfur Diet

EXPERIMENTAL

Participants will consume a novel elemental formula (mBiota Elemental, Good LFE, Santa Monica, CA) as their sole source of nutrition for two weeks. followed by a 10-week reduced sulfur diet. The reduced sulfur diet is designed to limit dietary sources of sulfur-containing compounds that may contribute to hydrogen sulfide production by the gut microbiota.

Dietary Supplement: Elemental formula (mBiota Elemental, Good LFE, Santa Monica, CA); Behavioral: Reduced Sulfur diet

Habitual Diet

ACTIVE COMPARATOR

Participants will complete a 2-week elemental diet intervention followed by a 10-week habitual diet. Participants will be instructed to resume and maintain their usual dietary intake without specific sulfur-restriction recommendations.

Dietary Supplement: Elemental formula (mBiota Elemental, Good LFE, Santa Monica, CA); Behavioral: Habitual Diet

Interventions

Reduced Sulfur diet BEHAVIORAL

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.

Reduced Sulfur Diet

Habitual Diet BEHAVIORAL

Participants randomized to the comparator group will continue their usual dietary intake for 10 weeks without specific dietary restrictions.

Habitual Diet

Elemental formula (mBiota Elemental, Good LFE, Santa Monica, CA) DIETARY_SUPPLEMENT

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 common dietary additives that may provoke inflammation.

Habitual Diet; Reduced Sulfur Diet

Eligibility Criteria

• Age: 19 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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;

Sponsors & Collaborators

• University of British Columbia: lead
• University of Calgary: collaborator

Study Sites (1)

University of British Columbia-Okanagan

Kelowna, British Columbia, V1V 1V7, Canada

Location

MeSH Terms

Conditions

Colitis, Ulcerative

Condition Hierarchy (Ancestors)

Colitis; Gastroenteritis; Gastrointestinal Diseases; Digestive System Diseases; Inflammatory Bowel Diseases; Colonic Diseases; Intestinal Diseases

Study Officials

• Natasha Haskey, RD, PhD

  University of British Columbia

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Natasha Haskey, PhD

CONTACT

250-807-9597; natasha.haskey@ubc.ca

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principle Investigator, Research Associate, Department of Biology

Study Record Dates

• First Submitted: May 29, 2026
• First Posted: June 11, 2026
• Study Start: June 1, 2026
• Primary Completion (Estimated): March 1, 2029
• Study Completion (Estimated): December 31, 2029
• Last Updated: June 11, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR, ANALYTIC CODE
• Access Criteria: A proposal for planned analyses must be submitted to the PI's of this research.

Locations

CA (1)