Spatial Analysis of the Intestinal Microbiota in Healthy Subjects

Study Overview
=================
Brief Summary
-----------------
Research on the human intestinal microbiota is common as there is rising evidence of its influence on host physiology and several diseases. Predominantly, it has been based on analyses of faecal samples because of their easy sampling. A minority of studies investigated the gut microbiota using mucosal samples. Not much is known about the spatial differences in microbiota composition along the large bowel. The spatial differences of the gut microbiota without preparation of the bowel have not been analysed yet. Furthermore, the composition of the microbiota of the luminal gut content has not been analysed yet. This study aims to gain knowledge of the microbial composition of luminal and mucosal samples at different segments of the lower gastrointestinal tract: ileum, caecum, ascending colon, transverse colon, descending colon, sigmoid colon and rectum, as well as of rectal swabs and faecal samples.

Detailed Description
-----------------
The investigators aim to evaluate complete colonoscopies from 10 healthy subjects. This study is used as a first explorative study of how the human gut microbiota is distributed along the lower gastrointestinal tract. No comparable studies in an uncleansed bowel have been performed so far. The number of subjects is based on other studies investigating the microbial composition of mucosal- and faecal-associated microbiota in which a sample size of 10 was enough to detect a difference. An equal number of men and women will be recruited. Drop-outs will be replaced.

Official Title
-----------------
Spatial Analysis of the Intestinal Microbiota in Healthy Subjects

Conditions
-----------------
Healthy Subjects

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Signed informed consent Age: 18-65 years Exclusion Criteria: Known organic gastrointestinal disease (e.g. inflammatory bowel disease, irritable bowel syndrome, chronic diarrhoea or constipation) History of or present gastrointestinal malignancy or polyposis Recent (gastrointestinal) infection (within last 6 months) History of major gastrointestinal surgery (e.g. gastric bypass) Eosinophilic disorders of the gastrointestinal tract Current communicable disease (e.g. upper respiratory tract infection) Malignant disease and/or patients who are receiving systemic anti-neoplastic agents Psychiatric diseases (e.g. dementia, depression, schizophrenia, autism, Asperger Syndrome) or other incapacity for adequate cooperation Chronic neurological/neurodegenerative diseases (e.g. Parkinson's disease, multiple sclerosis) Autoimmune disease and/or patients receiving immunosuppressive medications Major relevant allergies (e.g. food allergy, multiple allergies) Chronic pain syndromes (e.g. fibromyalgia) Chronic fatigue syndrome Obesity (body mass index>30) or metabolic syndrome Antimicrobial treatment or prophylaxis within the last 3 months Other chronic use of drugs that may affect the microbiome, e.g. proton pump inhibitors Females who are pregnant or breast-feeding Known clinically significant abnormal laboratory values Abuse of alcohol or drugs Probiotic intake within the last 6 weeks Bowel cleansing within the last 6 months Any clinically significant disease/condition which in the investigator's opinion could interfere with the results of the trial

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

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------
What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in the composition of the microbiota in luminal and mucosal samples along the large intestine Composition of the microbiota in luminal as well as mucosal samples | 16S rRNA-based next generation sequencing | 1 day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Microbial composition of rectal and faecal microbiota | 16S rRNA-based next generation sequencing | 1 day | 
| Metabolic profile in faecal samples along the intestinal tract | metabolomics | 1 day | 
| Gene expression of transporters for bacterial products in mucosal biopsies along the colon |  | 1 day |