Development of Non-invasive Methods to Study Gut Microbiome - Nutrition - Host Interactions

Study Overview
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Brief Summary
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The aim of this study is to develop and validate an adequate protocol of volatolome (volatile metabolites) measurement in breath of human volunteers (18-65 years) to study gut microbiome - nutrition - host interactions in a general healthy population. For this purpose, breath volatile metabolites (BVM) will be analyzed throughout test days in fasting state and after standardized meals using selected ion flow tube mass spectrometry (SIFT-MS). In addition, gut microbial functions linked notably to hydrogen/methane production, carbohydrates utilization (CAZymes), and in the production of other volatile metabolites of interest (i.e. indole, fatty acid derivatives, ...) will be unraveled through microbiome sequencing data analysis (in silico), metabolomic analyses and measurement of enzymatic activities from saliva, urine and/or fecal samples.

Official Title
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Development of Non-invasive Methods to Study Gut Microbiome - Nutrition - Host Interactions

Conditions
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Healthy

Intervention / Treatment
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* Other: Screening visit
* Other: Lactulose test
* Other: Administration of standardized meals with characterized dietary fiber content


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Woman or man, aged of 18 to 65 years; Body mass index (BMI) between 18 and 30 kg/m2; Non-smoker; Provision of signed and dated informed consent form; Stated willingness to comply with all study procedures and availability for the duration of the study; Speaking French. Exclusion Criteria: Subject with severe systemic disease (renal or hepatic failure, cancer, pancreatic cancer, chronic pancreatitis, asthma …) Subject with a history or current chronic/severe gastrointestinal disorder such as duodenal ulcer, chronic colitis, or chronic inflammatory disease of the digestive tract disease (Crohn's disease, ulcerative colitis), celiac disease or irritable bowel syndrome; Subjects with a history of digestive tract surgery (except appendectomy); Subject who had surgery within the two months prior to the study Subjects with psychiatric problems and/or using antipsychotics Current or recent (< 4 weeks) intake of antibiotics, fiber supplement, and/or any products modulating gut transit (laxative, anti-diarrheal, ...) or gut microbiota composition; these products will also be avoided for the duration of the study; Chronic intake of drugs, except contraceptive drug; Subject following a low-calorie diet and followed by a doctor or dietician in progress or recently (< 6 weeks); Women of childbearing age who are pregnant or breastfeeding or who wish to become pregnant within the next 6 weeks or who are not using an adequate method of contraception (e.g. oral contraception, intrauterine device (IUD), abstinence, ...); Subjects who drink more than 3 glasses of alcohol per day (> 30 g of alcohol per day); Subjects having participated to another clinical trial two weeks before the screening test visit; Subjects who practice an intense sport activity (more than 10 hours per week of intense activity); Language barrier, mental or legal incapacity, unwillingness or inability to understand or not being able to participate to the study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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

Primary Purpose: Other
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Screening<br>D-42 to D-7 | Other: Screening visit<br>* Subjects will be invited to perform the screening visit to sign the informed consent and then to ensure that they are able to participate in this study.<br>|
| Other: Lactulose<br>D0 | Other: Lactulose test<br>* Fasted subjects (at least 10 hours) will receive on oral load of 10 g of lactulose. Then, exhaled H2 will be measured every 30 minutes during 4 hours.<br>|
| Other: Meal 1<br>D14+/-7 | Other: Administration of standardized meals with characterized dietary fiber content<br>* Subjects will receive standardized breakfasts and lunches characterized in terms of dietary fiber content. Urine, saliva, feces samples will be collected. Breath test and gastrointestinal symptoms will be followed during maximum 8h. Subjects will also complete SF36 questionnaire, food diary and stool/transit questionnaire.<br>|
| Other: Meal 2<br>D16+/-7 | Other: Administration of standardized meals with characterized dietary fiber content<br>* Subjects will receive standardized breakfasts and lunches characterized in terms of dietary fiber content. Urine, saliva, feces samples will be collected. Breath test and gastrointestinal symptoms will be followed during maximum 8h. Subjects will also complete SF36 questionnaire, food diary and stool/transit questionnaire.<br>|
| Other: Meal 3<br>D18+/-7 | Other: Administration of standardized meals with characterized dietary fiber content<br>* Subjects will receive standardized breakfasts and lunches characterized in terms of dietary fiber content. Urine, saliva, feces samples will be collected. Breath test and gastrointestinal symptoms will be followed during maximum 8h. Subjects will also complete SF36 questionnaire, food diary and stool/transit questionnaire.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Exhaled volatile compounds | Selected Ion flow tube mass spectrometry (SIFT-MS) - Area under the curve (calculated on 8 hours following breakfast ingestion) | Throughout the entire study, approximately during 24 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gut microbiota | Illumina sequencing of 16S ribosomal deoxyribonucleic acid (rDNA), quantitative polymerase chain reaction (PCR) | Throughout the entire study, approximately during 24 months | 
| Salivary microbiota | Illumina sequencing of 16SrDNA, quantitative PCR | Throughout the entire study, approximately during 24 months | 
| Gastrointestinal symptom - discomfort | 100 mm Visual analog scale (0 = no symptom, 100 = very severe symptom) - Area under the curve (calculated on 8 hours following breakfast ingestion) | Throughout the entire study, approximately during 24 months | 
| Gastrointestinal symptom - nausea | 100 mm Visual analog scale (0 = no symptom, 100 = very severe symptom) - Area under the curve (calculated on 8 hours following breakfast ingestion) | Throughout the entire study, approximately during 24 months | 
| Gastrointestinal symptom - bloating | 100 mm Visual analog scale (0 = no symptom, 100 = very severe symptom) - Area under the curve (calculated on 8 hours following breakfast ingestion) | Throughout the entire study, approximately during 24 months | 
| Gastrointestinal symptom - flatulences | 100 mm Visual analog scale (0 = no symptom, 100 = very severe symptom) - Area under the curve (calculated on 8 hours following breakfast ingestion) | Throughout the entire study, approximately during 24 months | 
| Gastrointestinal symptom - gastrointestinal reflux | 100 mm Visual analog scale (0 = no symptom, 100 = very severe symptom) - Area under the curve (calculated on 8 hours following breakfast ingestion) | Throughout the entire study, approximately during 24 months | 
| Gastrointestinal symptom - cramps | 100 mm Visual analog scale (0 = no symptom, 100 = very severe symptom) - Area under the curve (calculated on 8 hours following breakfast ingestion) | Throughout the entire study, approximately during 24 months | 
| Gastrointestinal symptom - rumbling | 100 mm Visual analog scale (0 = no symptom, 100 = very severe symptom) - Area under the curve (calculated on 8 hours following breakfast ingestion) | Throughout the entire study, approximately during 24 months | 
| Gastrointestinal symptom - burps | 100 mm Visual analog scale (0 = no symptom, 100 = very severe symptom) | Throughout the entire study, approximately during 24 months | 
| Gut microbiota metabolic capacity | Enzymatic analysis via in-vitro studies, incubation of fecal extracts | Throughout the entire study, approximately during 24 months | 
| Exhaled hydrogen (H2) | Lactotest 202 - Area under the curve (calculated on 4 hours following lactulose ingestion) | Throughout the entire study, approximately during 24 months | 
| Exhaled methane (CH4) | Lactotest 202 - Area under the curve (calculated on 8 hours following breakfast ingestion) | Throughout the entire study, approximately during 24 months | 
| Exhaled carbon dioxide (CO2) | Lactotest 202 - Area under the curve (calculated on 4 hours following lactulose ingestion) | Throughout the entire study, approximately during 24 months | 
| Carbohydrates utilization - Carbohydrate active enzymes (CAZymes) | Saliva enzymatic activities | Throughout the entire study, approximately during 24 months | 
| Nutrient intake | Food diary (daily log of what the volunteer eats and drinks each day) | Throughout the entire study, approximately during 24 months | 
| Dietary habits | Food frequency questionnaire (FFQ) (record the volunteers' usual diet and dietary habits) | Throughout the entire study, approximately during 24 months | 
| Well-being | The short form (36) health survey (SF36) (0 = worse physical and mental health functioning, 100 = best physical and mental health functioning) | Throughout the entire study, approximately during 24 months | 
| Transit - frequency | Questionnaire on stool frequency (record each defecation time) | Throughout the entire study, approximately during 24 months | 
| Transit - type of stool | Bristol stools scale (BSS) (classify the form of feces into 7 categories; type 1 = severe constipation, type 2 = mild constipation, types 3 and 4 = normal, type 5 = lacking fiber, type 6 = mild diarrhea, type 7 = severe diarrhea) | Throughout the entire study, approximately during 24 months | 
| Transit - ease of passage | 5-point Likert's scale (1 = very difficult to defecate, 5 = very easy to defecate) | Throughout the entire study, approximately during 24 months | 
| Transit - level of emergency | 5-point Likert's scale (1 = very urgent need to defecate, 5 = very nonurgent need to defecate) | Throughout the entire study, approximately during 24 months | 
| Transit - empty feeling | 5-point Likert's scale (1 = very nonempty feeling after defecation, 5 = very empty feeling after defecation) | Throughout the entire study, approximately during 24 months |