MICRO-study: The IntelliCap® System as a Gastrointestinal Fluid Sampling Tool

The gut microbiota is involved in regulation of host metabolic and immune pathways, and is an important target for dietary interventions. Studies on human microbiota are mainly based on the analysis of fecal samples. The microbiota in the small intestine is at least equally relevant for health as in the large intestine, but the regional composition differs largely. Small intestinal sampling requires invasive procedures. Recently, an electronic medical device, the IntelliCap® system, was developed for the site-specific delivery of drugs in the gastrointestinal tract and patient monitoring. This capsule has been adapted to be used to aspirate liquid from its environment. The IntelliCap® system may offer a minimally-invasive tool for sampling of small intestinal fluid in humans for microbiota analysis.

Objective: To evaluate the IntelliCap® system as a tool to study changes in small intestinal microbiota composition in humans in vivo and its safety and tolerability.

Study design: A randomized cross-over controlled feeding trial in humans will be performed in 10 healthy male volunteers (age 18-30 yr). Two diets are used: a three-day high-protein versus a high-carbohydrate diet, each preceded by a washout diet. These diets target microbiota with fundamentally different fermentation requirements. The IntelliCap® capsule is administered after both intervention periods to collect a fluid sample from the distal small bowel. In parallel, fecal samples are collected. Microbiota composition is analyzed by sequencing using Illumina technology followed by dedicated bioinformatic analysis. Blood samples will be collected and stored to measure metabolic parameters and markers of satiety that can potentially be correlated to the microbiota data.

Inclusion criteria

• Healthy males
• Age 18-30yrs
• BMI between 20-30 kg/m2
• Regular bowel movement (defecation on average once a day)
• Signed informed consent

Exclusion criteria

• History or presence of any clinically important disease or disorder which, in the opinion of the Investigator, may either put the subject at risk because of participation in the study, or influence the results or the subject's ability to participate in the study (e.g. diabetes, cardiovascular disease, gastrointestinal disease, renal failure, cancer, infectious disease).
• Presence of swallowing disorder
• Use of any prescribed or non-prescribed medication (other than paracetamol) including antacids, analgesics, and herbal remedies during the three (3) weeks prior to study start.
• Carrying a pacemaker or any other (implanted) medical electronic device
• Scheduled for an MRI scan during the study period
• Tobacco smoker
• Unstable body weight (weight gain or loss >5kg in the past 3 months)
• Use of antibiotics within 2 months of starting the study or planned during the study
• Use of pro- or prebiotics
• Constipation/infrequent bowel movement
• Abuse of drugs/alcohol (alcohol: >4 consumptions/day or >20 consumptions/week)
• Having diarrhea within 2 months prior to the study start
• Vegetarianism/Veganism
• Allergic for dairy products (milk allergy or lactose intolerance)
• Known or suspected allergy to any product used in this study
• Not willing to have an X-ray if the capsule is not recovered from the faeces
• Personnel of Wageningen University, Division of Human Nutrition.
• Current participation in other research from the Division of Human Nutrition
• Participation in another biomedical study