Exploring exhaled breath biomarkers for lactose intolerance diagnosis: the Lactobreath pilot study protocol.
Stamatios Giannoukos, Kathryn Jane Burton-Pimentel, Roxane Guillod...
https://pubmed.ncbi.nlm.nih.gov/40754327Actively Recruiting
Phase Not Applicable
Age: 18Years - 65Years
All Genders
Healthy Volunteers
ID06177938
Lactobreath: A Pilot Study to Diagnose Lactose Intolerance Based on the Exhaled Breath Metabolome
Led by ETH Zurich · Updated on 2025-07-08
120
Participants Needed
1
Research Sites
N/A
Total Duration
On this page
Sponsors
E
ETH Zurich
Lead Sponsor
A
Agroscope Liebefeld-Posieux Research Station ALP
Collaborating Sponsor
AI-Summary
What this Trial Is About
Research is investigating lactose intolerance, a common food intolerance caused by difficulty digesting certain carbohydrates called FODMAPs. Existing diagnosis methods like exclusion diets or hydrogen breath tests have limitations. This study aims to identify breath markers linked to lactose tolerance and intolerance, using lactose intolerance as a model to improve diagnosis and personalize nutrition. It also explores genetic factors and metabolic traits from urine samples to help guide low FODMAP dietary recommendations. Participants will undergo a home lactose tolerance screening using a lactose powder test and saliva collection for genetic analysis. Based on their genetic profiles and symptoms, 120 participants will be divided into three groups. They will consume either a lactose or glucose solution in a randomized, triple-blind setup, swallowing a gas-sensing capsule to monitor intestinal gases. Several biological samples will be collected before and up to six hours after ingestion, including breath, breath condensate, urine, and symptom questionnaires. Participants will complete dietary recalls and provide fecal samples before the intervention. On test day, they will follow a standardized low-FODMAP diet for three days and attend a laboratory visit for sample collection and testing. Breath samples will be collected at nine timepoints post-ingestion, and urine samples will be analyzed for metabolomics. The study measures include diagnostic breath profiles, hydrogen levels, intestinal gas monitoring, and clinical symptoms. A follow-up visit will confirm the capsule's excretion and conclude participation.
CONDITIONS
Brief Title
Lactobreath: A Study to Diagnose Lactose Intolerance Using Breath Markers
Who Can Participate
Age: 18Years - 65Years
All Genders
Healthy Volunteers
Eligibility Criteria
You may qualify if you...
- Men and women
- Living in the Zurich area or nearby in Switzerland
- Able and willing to provide informed consent and participate in study procedures
- Aged 18 to 65 years at screening
- Agree to avoid all other dairy intolerance treatments during the study
- Willing to attend all study visits and complete procedures, including fasting
- Able to understand and provide consent in English and/or German
You will not qualify if you...
- Allergy to milk
- Currently pregnant or lactating
- Use of tobacco or nicotine products within 3 months before screening
- Diagnosed with disorders affecting gastrointestinal motility such as gastroparesis, amyloidosis, neuromuscular diseases, collagen vascular diseases, alcoholism, uremia, malnutrition, or untreated hypothyroidism
- History of gastrointestinal surgeries altering normal function (except uncomplicated surgeries over 12 months ago)
- Suspected obscure gastrointestinal bleeding
- Past or present organ transplant, chronic pancreatitis, pancreatic insufficiency, biliary disease, celiac disease, diverticular disease, inflammatory bowel disease, strictures, fistulas, gastrointestinal obstructions, or conditions confounding adverse event collection
- Diabetes mellitus
- Congestive heart failure
- HIV, hepatitis B or C infection
- Body mass index over 35 kg/m2
- Swallowing disorders
- Presence of implantable or portable electro-mechanical medical devices
- Recent bowel preparation within 4 weeks
- Chronic antacid or proton pump inhibitor use
- Recent systemic antibiotic use within 2 months
- History of alcohol or drug abuse in the past 12 months
- Severe irritable bowel syndrome with symptom severity over 400
- Vegan or vegetarian diet
- Any conditions affecting participation or protocol compliance
- Enrollment in another clinical trial within the last 3 months
- Screening test showing GI symptoms with lactose ingestion and genetic lactase persistence
AI-Screening
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Your Study Journey
Screening
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 home screening and enrollment visit involving a lactose tolerance test and saliva sample collection
Baseline Measures
Duration - Up to 4 weeks before intervention day
Participants complete dietary recalls and collect fecal samples at home to assess microbiota and diet before the intervention.
4 dietary recall sessions on consecutive days and 3 fecal sample collections at home
Intervention Day
Duration - 1 day
Participants follow a standardized restricted diet for 3 days before the test, then undergo carbohydrate challenge testing with lactose or glucose solutions at the test laboratory. Various breath, urine, and symptom assessments are performed during and after the test.
1 in-person visit with multiple sample collections and assessments over 6 hours post-ingestion
Follow-up
Duration - Within days following the intervention day
Participants return for a visit to confirm the excretion of the gas-sensing capsule, concluding the study procedures.
1 follow-up visit
Trial Site Locations
Total: 1 location
1
ETH Zurich
Zurich, Canton of Zurich, Switzerland, 8093
Actively Recruiting
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Research Team
S
Stamatios Giannoukos, PhD
K
Kathryn J. Pimentel, PhD
How is the study designed?
Study Type
INTERVENTIONAL
Masking
TRIPLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
BASIC_SCIENCE
Number of Arms
2
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