The Effects of Lactose Intolerance on Gastrointestinal Function and Symptoms in a Chinese Population

Study Overview
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Brief Summary
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Lactose is a carbohydrate found in milk,and Lactase Deficiency (LD) is a condition in which the small intestine cannot digest this carbohydrate due to absent or insufficient amounts of lactase.Individuals with LD may be intolerant of lactose in the diet and experience abdominal cramps, bloating and diarrhea; however the response is variable.Some tolerate moderate amounts of lactose without adverse effect,whereas others experience severe symptoms in response to even small doses. These problems may be representative of wider issues regarding individual tolerance to diet containing ubiquitous poorly absorbed, fermentable carbohydrates (such as: fructose, fructans)and be relevant to symptom generated in patients with diarrhea predominant irritable bowel syndrome (D-IBS). This project will investigate the effects of diet,lifestyle stress and psychiatric dietary on the development of functional gastrointestinal symptoms. Lactose will be used to assess tolerance to dietary challenge, a test that is particularly relevant in a Chinese population with a high prevalence of lactase deficiency.

Detailed Description
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Study #1: Questionnaire study in general Chinese population (n=2000). Study #2: Physiologic study in patients attending gastroenterology clinic (n=600) including in subgroups assessment of genetic factors,tolerance to lactose challenge and assessment of visceral sensitivity. Study #3: Assessment of appropriate dosage of lactose hydrogen breath test in a population with high-prevalence of lactase deficiency. Study #4: Impact of a determined dietary intervention on abdominal symptoms compatible with D-IBS. study #5: The association of visceral sensitivity induced by LI with mucosal immune activation and psychological factors in D-IBS patients

Official Title
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The Effects of Lactose Intolerance on Gastrointestinal Function and Symptoms in a Chinese Population

Conditions
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Lactose Intolerance, Irritable Bowel Syndrome

Intervention / Treatment
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* Dietary Supplement: dietary restriction


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged at least 16 years old and not more than 75 years old. Ability to communicate with the investigator, complete study questionnaires (with help of investigator) and provide informed consent. Exclusion Criteria: Progressive, severe disease requiring active medical management (e.g. advanced cardiac, liver, renal or neurological disease, advanced cancer) History of significant gastrointestinal pathology (other than gastro-oesophageal reflux disease and functional bowel diseases) History of gastro-intestinal surgery (except appendicectomy, cholecystectomy, hernia repair). Evidence of active drug or alcohol abuse

Ages Eligible for Study
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Minimum Age: 16 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: dietary<br> | Dietary Supplement: dietary restriction<br>* restrict intake of lactose<br>* Other names: exclusion diet；food restriction；dietary treatment;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To assess the effects of lactose intolerance on gastrointestinal function and symptoms |  | Three years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To measure the intake of dietary lactose in the adult general population and in patients with IBS |  | three years | 
| To assess genetic factors, tolerance to lactose challenge and visceral sensitivity. |  | three years | 
| To assess appropriate dosage of lactose hydrogen breath test |  | two years | 
| To determine the impact of a determined dietary intervention on abdominal symptoms compatible with D-IBS. |  | three years | 
| To explore the association of visceral sensitivity induced by LI with mucosal immune activation and psychological factors in D-IBS patients |  | two years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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lactose intolerance, DNA sequencing, psychosocial factors, irritable bowel syndrome, visceral hypersensitivity