Lactobreath: A Study to Diagnose Lactose Intolerance Using Breath Markers

NCT06177938 | Recruiting

• 1 other identifier: NEX_Lactobreath
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

Food intolerances affect many people and can cause discomfort and dietary challenges. One common cause is difficulty digesting certain carbohydrates called FODMAPs. Diagnosing food intolerance is often done by excluding and then slowly reintroducing these carbohydrates or using a hydrogen breath test, but these methods have limitations. To address these issues, this project uses the breath we exhale to find markers for lactose intolerance as a model for food intolerance diagnosis. Our aim is to identify breath markers for lactose tolerance and intolerance and link them to metabolic traits, including those found in urine. We use a real-time breath analysis method and a special sensor to measure gases in the digestive system, and we also explore genetic factors using saliva samples. This project aims to help clinicians better identify patients who should follow low FODMAP diets and provide non-invasive breath tests to predict how patients will respond to these diets. It will also advance the use of breath analysis for personalized nutrition, contributes to the broader field of food intolerance research, and has the potential to benefit millions of individuals worldwide.

Conditions

Lactose Intolerance

Keywords

Lactose; Food Biomarker; Metabolome; Food Intolerance; Microbiota; Breath

Outcome Measures

Primary Outcomes (1)

• Diagnostic performance of the breath profile associated with lactose malabsorption (lactobreath profile)

  Selected metabolites identified from exhaled breath after lactose intake that can collectively discriminate clinical traits associated with lactose malabsorption. Several parameters with be assessed: sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), the likelihood ratio of a positive test (LR+), the likelihood ratio of a negative test (LR-).

  Breath samples will be collected at 9 time points following the ingestion of lactose (15 min, 30 min, 60 min, 90 min, 120 min, 180 min, 240 min, 300 min, and 360 min).

Secondary Outcomes (5)

• Urine metabolome

  Two pooled postprandial timepoints following lactose intake (0-3h and 3-6h)

• Metabolome of exhaled breath condensate (EBC) samples

  9 postprandial timepoints following lactose intake (15 min, 30 min, 60 min, 90 min, 120 min, 180 min, 240 min, 300 min, and 360 min)

• Hydrogen breath test

  9 postprandial timepoints following lactose intake (15 min, 30 min, 60 min, 90 min, 120 min, 180 min, 240 min, 300 min, and 360 min)

• Intestinal gases and GI transit assessment

  Semi-continuous (every 20 seconds) postprandial assessment following lactose intake until excretion of the capsule

• Clinical symptoms of lactose intolerance

  5 postprandial timepoints following lactose intake (30 min, 60 min, 120 min, 180 min, and 360 min)

Study Arms (2)

Lactose solution

EXPERIMENTAL

Single ingestion of a lactose solution (25 g lactose dissolved in 150 mL water).

Dietary Supplement: Lactose solution/Glucose solution

Glucose solution

PLACEBO COMPARATOR

Single ingestion of a glucose solution (13 g glucose dissolved in 150 mL water).

Dietary Supplement: Lactose solution/Glucose solution

Interventions

Lactose solution/Glucose solution DIETARY_SUPPLEMENT

Single ingestion of a lactose/glucose solution.

Glucose solution; Lactose solution

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Men and women
• Swiss and non-Swiss living in the Zurich area (if necessary, beyond Zürich in Switzerland),
• Ability/desire to provide informed consent and partake in the procedures of the study
• Aged 18-65 years at screening
• Agreement to refrain from all other treatments and products used for dairy intolerance (e.g., Lactaid® dietary supplements) during study involvement
• Willing to return for all study visits and complete all study-related procedures, including fasting before and during the intervention
• Able to understand and provide written informed consent in English and/or German.

You may not qualify if:

• Allergic to milk
• Currently pregnant
• Currently lactating
• Cigarette smoking or other use of tobacco or nicotine-containing products within 3 months of screening
• Diagnosed with any of the following disorders known to be associated with abnormal GI motility: gastroparesis, amyloidosis, neuromuscular diseases (including Parkinson's disease), collagen vascular diseases, alcoholism, uremia, malnutrition, or untreated hypothyroidism
• History of surgery that alters normal GI tract function, including but not limited to: GI bypass surgery, bariatric surgery, gastric banding, vagotomy, fundoplication, pyloroplasty (N.B. history of uncomplicated abdominal or GI surgeries such as removal of an appendix \>12 months before screening will not be excluded)
• Suspected obscure GI bleeding
• Past or present: organ transplant, chronic pancreatitis, pancreatic insufficiency, symptomatic biliary disease, coeliac disease, diverticular disease, inflammatory bowel disease, strictures (suspected or known), fistulas, or any GI obstruction, gastroparesis, history of gastric bezoar or any other medical condition with symptoms that could confound collection of adverse events
• Diabetes mellitus
• Congestive heart failure
• Human immunodeficiency virus, hepatitis B, or hepatitis C
• Body mass index \> 35 kg/m2
• Swallowing disorders or dysphagia to food or pills
• Presence of implantable or portable electro-mechanical medical devices (e.g. pacemakers)
• Recent bowel preparation for endoscopic or radiologic investigation within 4 weeks of screening (e.g., colonoscopy preparation)

Sponsors & Collaborators

• ETH Zurich: lead
• Agroscope Liebefeld-Posieux Research Station ALP: collaborator
• Swiss Allergy Centre: collaborator
• University of Zurich: collaborator

Study Sites (1)

ETH Zurich

Zurich, Canton of Zurich, 8093, Switzerland

RECRUITING

Related Publications (1)

• Giannoukos S, Burton-Pimentel KJ, Guillod R, Vergeres G, Pohl D. Exploring exhaled breath biomarkers for lactose intolerance diagnosis: the Lactobreath pilot study protocol. BMJ Open. 2025 Aug 3;15(8):e107256. doi: 10.1136/bmjopen-2025-107256.

  PMID: 40754327 DERIVED

MeSH Terms

Conditions

Lactose Intolerance; Food Intolerance

Condition Hierarchy (Ancestors)

Malabsorption Syndromes; Intestinal Diseases; Gastrointestinal Diseases; Digestive System Diseases; Carbohydrate Metabolism, Inborn Errors; Metabolism, Inborn Errors; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Metabolic Diseases; Nutritional and Metabolic Diseases; Signs and Symptoms, Digestive; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Central Study Contacts

Stamatios Giannoukos, PhD

CONTACT

+41 44 632 61 12; stamatios.giannoukos@org.chem.ethz.ch

Kathryn J. Pimentel, PhD

CONTACT

+41(0)58 467 3187; Kathryn.pimentel@agroscope.admin.ch

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: NA- No other parties masked
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: The study intervention is a single acute postprandial carbohydrate challenge (lactose or glucose) test. Baseline assessments of fecal microbiota composition and usual diet are made on 3 days, within four weeks of the intervention day. Dietary restrictions apply 3 days before the carbohydrate challenge, and participants fast on the morning of the intervention day. The intervention day begins with the collection of baseline urine and breath. Participants are assigned to one of the two carbohydrate challenges. The intervention begins with the ingestion of the carbohydrate solution (25 g of lactose or 13 g glucose) dissolved in 150 mL water, followed by the ingestion of a commercially available gas-sensing capsule to measure intestinal gases. Postprandial breath sampling is conducted over 6 hours for H2 and metabolome analyses. Lactose intolerance symptoms are assessed, and two pools of urine are collected. Intestinal excretion of the gas-sensing capsule marks the end of the intervention.

Study Record Dates

• First Submitted: December 11, 2023
• First Posted: December 20, 2023
• Study Start: June 24, 2024
• Primary Completion: December 1, 2025
• Study Completion: December 1, 2025
• Last Updated: July 8, 2025

Record last verified: 2025-02

Data Sharing

• IPD Sharing: Will share

Locations

CH (1)