Clinical Trials Logo

Clinical Trial 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.


Clinical Trial Description

Genetic and lactose tolerance screening For all eligible participants, a screening home test will be conducted. The home screening test kit will contain lactose powder and accompanying information in order for the subjects to conduct a lactose tolerance test (according to the LHBT protocol) at home. The test will be adapted from recent guidelines (https://www.esnm.eu/guidelines.html) that propose the use of 25g of lactose for lactose tolerance testing, including a questionnaire to quantitatively assess symptoms. The home screening test kit will also provide material to collect a saliva sample to determine genetic polymorphisms commonly modulating LP. A total of 120 participants will be selected and distributed into three groups based on their LP genetic profiles and response to the ingestion of 25 g of lactose (lactose solution): - 24 genetically LP subjects with no GI symptoms in response to the ingestion of lactose (group 1) - 24 genetically lactase-non-persistent (LNP) subjects with no GI symptoms in response to the ingestion of lactose (group 2) - 72 genetically LNP subjects with any GI symptoms in response to lactose ingestion (group 3). Study procedures Baseline measures: For each subject, baseline measurement of microbiota and diet will be made within four weeks of the intervention day. The assessment of diet and the genomic characterization of the fecal microbiota will be performed in parallel with repeated measures - Four 24 h dietary recalls will be completed using an adapted version of the myfood24 online platform on four consecutive days, during days -30 to -7, before the intervention day - Three fecal samples will be collected by the participants at home, ideally on three consecutive days, on days +1, +2, and +3 relative to the first 24 h dietary recall. Intervention day: The diet of all selected participants will be restricted for the three days before the carbohydrate challenge test day to ensure that all FODMAPs are avoided with a standardized diet provided to the participants for the three days before the test. On the morning of the test day, the participants will be asked to collect their first test sample, the morning urine and consume 300 mL of water at home. Upon arrival in the test laboratory, the participants will deliver a further urine sample and baseline breath samples for the breath metabolome and hydrogen breath test. The urine samples will be used for metabolomics analysis and, in the case of female participants, for a pregnancy test. Participants with a positive pregnancy test will be excluded. The participants will also fill out the questionnaire on LI (as used for the screening survey) to describe symptoms of LI before the test (baseline symptoms). The 120 participants will be assigned to one of the two carbohydrate challenges using stratified randomization based on the three groups defined by the pre-screening tests. 100 participants will be assigned to the experimental intervention (lactose). The remaining 20 participants (4 participants from each groups 1 and 2 and 12 participants from group 3) will be assigned to the control intervention (glucose). The participants and investigators will be blinded during testing to the type of carbohydrate solution assigned. For each participant, the carbohydrate solution will need to be consumed in a time-lapse of 5 min. Following the solution intake, participants will be asked to rinse their mouths with a standard quantity of water (500 mL) to avoid the detection of solution-relevant residual molecules in the oral cavity. The participants will swallow a commercially available gas-sensing capsule within the 5 minutes following the lactose or glucose solution intake to monitor intestinal gases and GI transit time. Postprandial breath, exhaled breath condensate (EBC) and urine samples will then be collected at predefined times during the 6 h following consumption of the assigned test product. Breath sampling will be performed using a secondary electrospray ionization source coupled to a high-resolution mass spectrometry system (SESI-HR-MS) for direct and real-time detection of volatile organic compounds (VOC) and using an H2 breath sensor (e.g. QuinTron BreathTracker Digital Microlyzer) for detection of exhaled hydrogen. EBC samples will be collected using a spirometry filter connected to a glass cold trap cooled to -78°C. In addition, the participants will fill out the questionnaire for symptoms of LI to describe the symptoms during the 6 h postprandial assessment . To normalize participants' hydration, particularly to facilitate the urine collection, the participants will be offered a standardized quantity of water based on their body weight to be consumed in regular portions during the post-ingestion period. No other foods or fluids will be permitted during the laboratory testing. Intestinal excretion of the gas-sensing capsule will mark the end of the intervention. A follow-up visit to confirm the excretion of the gas-sensing capsule will conclude the study. Additional subjects will be recruited should the number of participants completing the lactose and glucose tests fall below the targeted numbers. ;


Study Design


Related Conditions & MeSH terms


NCT number NCT06177938
Study type Interventional
Source ETH Zurich
Contact Stamatios Giannoukos, PhD
Phone +41 44 632 61 12
Email stamatios.giannoukos@org.chem.ethz.ch
Status Recruiting
Phase N/A
Start date January 2024
Completion date February 2025

See also
  Status Clinical Trial Phase
Not yet recruiting NCT05100719 - The Role of Irritable Bowel Syndrome in Lactose Intolerance (LION) N/A
Completed NCT02518295 - β-galactosidase Producing Probiotic Strains to Improve Lactose Digestion N/A
Completed NCT00599859 - Effects of Lactose on Fecal Microflora N/A
Completed NCT02636413 - Evaluation of LacTEST for the Diagnosis of Hypolactasia in Adults and Elderly Patients Presenting With Clinical Symptoms of Lactose Intolerance Phase 4
Completed NCT02406469 - Effects Comparison of A1 and A2 Milk on Gastrointestinal Physiology, Symptoms and Cognitive Behavior Phase 4
Terminated NCT00247806 - Prevalence of Lactose Intolerance Following Stem Cell Transplantation Phase 1
Completed NCT03814668 - Effect of Probiotic Supplementation on Lactose Maldigestion Induced by Lactose Solution N/A
Completed NCT03860051 - Association Between Lactase Deficiency, and the Small Intestinal Microbiome in Adults.
Not yet recruiting NCT06107088 - Effect of a Combination of Lactase and L. Salivarius DSM 34078 in Individuals With Lactose Intolerance N/A
Completed NCT02703987 - HYBRID: Hydrogen Breath Test in Lactose Digestion N/A
Completed NCT00395954 - Amount of Lactose Causing Symptoms in Lactose Intolerant People Phase 0
Completed NCT01593800 - The Effect of Probiotics on Lactose Intolerance N/A
Completed NCT04164394 - Effect of I31 Probiotic on Lactose Intolerance N/A
Recruiting NCT05668468 - A Bifido Bacteria to Improve Lactose Digestion and Tolerance N/A
Completed NCT03563846 - Effect of a Standard Meal on the Pharmacokinetic Profile of RP-G28 in Healthy Adult Male and Female Subjects Phase 1
Recruiting NCT02085889 - Fructose and Lactose Intolerance and Malabsorption in Functional Gastrointestinal Disorders
Completed NCT03597516 - Evaluation of the Efficacy, Durability, Safety, and Tolerability of RP-G28 in Patients With Lactose Intolerance Phase 3
Not yet recruiting NCT03563859 - Evaluation of Efficacy, Durability, Safety, and Tolerability of RP-G28 in Patients With Lactose Intolerance Phase 3
Completed NCT02171403 - Comparison of the Colonic Metabolism in Patients With Lactose Intolerance and Healthy Controls N/A
Completed NCT01145586 - A Non-inferiority, Multicenter and Randomized, Multiple-Dose Study About a Treatment to Hypolactasia Phase 3