Lactobreath: A Pilot Study to Diagnose Lactose Intolerance Based on the Exhaled Breath Metabolome
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 112
- 试验地点
- 3
- 主要终点
- Diagnostic performance of the breath profile associated with lactose malabsorption (lactobreath profile)
研究概览
简要总结
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.
详细描述
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
盲法说明
NA- No other parties masked
入排标准
- 年龄范围
- 18 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •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.
排除标准
- •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)
- •Chronic antacid and/or proton pump inhibitor use
- •Recent use of systemic antibiotics, defined as use within 2 months prior to screening
- •History of ethanol (alcohol) and/or drug abuse in the past 12 months
- •Patients with severe irritable bowel syndrome (IBS) (i.e., IBS Symptom Severity Score >400)
- •Dietary restrictions including vegan or vegetarian diet.
- •Any other conditions/issues noted by the study staff and/or Principal Investigator that would impact participation and/or protocol compliance.
- •Previous enrollment in another clinical trial within the last 3 months.
- •Results of the screening test showing GI symptoms in response to lactose ingestion and genetic LP.
研究组 & 干预措施
Lactose solution
Single ingestion of a lactose solution (25 g lactose dissolved in 150 mL water).
干预措施: Lactose solution/Glucose solution (Dietary Supplement)
Glucose solution
Single ingestion of a glucose solution (13 g glucose dissolved in 150 mL water).
干预措施: Lactose solution/Glucose solution (Dietary Supplement)
结局指标
主要结局
Diagnostic performance of the breath profile associated with lactose malabsorption (lactobreath profile)
时间窗: 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).
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-).
次要结局
- 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))
- Clinical symptoms of lactose intolerance(5 postprandial timepoints following lactose intake (30 min, 60 min, 120 min, 180 min, and 360 min))
- Urine metabolome(Two pooled postprandial timepoints following lactose intake (0-3h and 3-6h))
- 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)