Evaluation of Methods for Measuring Gastrointestinal Transit and Food Reward in Healthy Individuals - The PRESET Study

The wireless motility capsule technology, SmartPill™, can be used to assess gastric emptying and gastrointestinal (GI) transit time. The SmartPill is usually ingested together with a SmartBar™ which is a snack bar with a nutrient composition that differs substantially from a normal western diet. The primary aim of the present study is to compare effects of a SmartBar™ and a standard mixed meal on gastric emptying and GI motility.

Background: The wireless motility capsule technology, SmartPill™, can be used to assess GI transit time including gastric emptying and small and large bowel transit time based on measurements of pH, pressure and temperature. The SmartPill™ allows for GI motility measurements under free-living conditions without radiation. The SmartPill is usually ingested together with a SmartBar™ which is a snack bar with a nutrient composition that differs substantially from a normal western diet. GI motility in response to meals plays an important role in regulation of e.g. appetite and glucose metabolism. Changes in appetite and metabolism in response to interventions are often assessed using a meal test and GI motility is assessed at the research facilities. The use of SmartPill™ in combination with a meal test would allow for assessment of GI motility under subsequent free-living conditions and improve our understanding of the effects of interventions on the integrative relationship between food intake, GI motility and metabolism. Most of our daily decisions and actions affecting energy intake are driven by the non-conscious processes; however, appetite is often assessed from participants' self-report which is associated with limitations such as desire to report socially desirable answers. Little is known about the complex interrelationship between biological markers of appetite e.g. GI hormones and subjective and objective measures of food related behavior under fasting and fed conditions.

The PRESET study has the following objectives:

1. To compare effects of a SmartBar™ and a standard mixed breakfast meal on gastric emptying and GI transit time measured using the SmartPill™ in normal-weight individuals.
2. To compare effects of a SmartBar™ and a standard mixed breakfast meal on concentrations of metabolites and pancreatic and GI hormones, and subjective and objective measures of appetite, food reward and food related behavior assessed from biometric responses (facial expression, galvanic skin response and eye tracking) to visual food stimuli varying in fat content and taste during the computerized Leeds Food Preference Questionnaire (LFPQ) in normal-weight individuals.
3. To assess potential associations between gastric emptying and GI motility, biological markers of appetite and subjective appetite and objective measures of food related behavior from biometric responses to visual food stimuli during the LFPQ in the fasting state and in response to meals in normal-weight individuals.

Testing includes assessments in the fasting state and in response to consumption of the SmartBar™ and a standard mixed meal (4-hour meal tests and subsequent 6-days free-living assessment period) on two separate test days.

Eligibility Criteria:
Inclusion Criteria:

• Body mass index: 18.5 to 24.9 kg/m2

Exclusion Criteria:

* Unable to understand the informed consent and the study procedures;
* Self-reported history of an eating disorder in the past three years
* Self-reported weight change (\>5 kg) within three months prior to inclusion
* HbA1c: ≥5.7 % (≥39 mmol/mol)
* Uncontrolled medical issues including but not limited to cardiovascular pulmonary, rheumatologic, hematologic, oncologic, infectious, GI or psychiatric disease; diabetes or other endocrine disease; immunosuppression
* Current treatment with medication or medical devices which affect GI motility and transit time (prokinetics, antidiarrheals, laxatives)
* Current treatment with medication which affect glucose metabolism or appetite
* Current treatment with beta blockers or peroral steroids
* Current treatment with non-steroidal anti-inflammatory drugs, tricyclic antidepressants, selective serotonin re-uptake inhibitors or opioids
* Bariatric surgery
* GI symptoms or diseases such as regular (weekly) abdominal pain, dysphagia, gastric bezoars, strictures, fistulas, bowel obstructions, diverticulitis, celiac disease, Crohn's disease, ulcerative colitis or proctitis
* Alcohol/drug abuse or in treatment with disulfiram (Antabus) at time of inclusion
* Pregnant or lactating women
* Fertile women not using birth control agents including oral contraceptives, gestagen injection, subdermal implants, hormonal vaginal ring, transdermal application, or intra-uterine devices
* Concomitant participation in other research studies