The Role of FODMAPs in Upper GI Effects, Colonic Motor Activity and Gut-brain Signaling at the Behavioral Level
Condition: Irritable Bowel Syndrome
MeSH terms: Irritable Bowel Syndrome
Study type: Interventional

Summary: 
      In this study, the investigators aim to assess the effect of acute FODMAP infusion on gastric
      motility and on gastrointestinal and psychological symptoms. 20 healthy volunteers and 20
      patients with irritable bowel syndrome (IBS) will undergo respectively four and two/three
      pressure measurements of the stomach after an overnight fast as a measure for gastric
      motility. During this pressure measurement, which takes approximately 4 hours, one of four
      FODMAP or control solutions will be administered directly into the stomach through a
      nasogastric tube. Administration will be stopped when the participant is fully satiated. The
      four solutions that will be tested in healthy volunteers are (1) a fructan solution, (2) a
      fructose solution, (3) a FODMAP mix and (4) a glucose solution as a control. In IBS patients,
      only the fructan and glucose solution will be tested, where after they can choose to come for
      a third visit to test the fructose solution. The solutions will be tested on separate
      occasions in a randomized order.

      During the pressure measurement, participants will be asked to complete several
      questionnaires: (1) a gastrointestinal symptom questionnaire to assess their gastrointestinal
      symptoms, (2) a satiation questionnaire during infusion of one of the solutions, (3)
      psychological questionnaires (POMS, SAM, PANAS and STAI) to evaluate possible psychological
      effects of FODMAP infusion.

      The investigators hypothesize that there will be differences in gastric motility between
      healthy volunteers and IBS patients. Furthermore, it is hypothesized that gastrointestinal
      symptoms will be increased in IBS patients, and that FODMAP infusion will have more
      psychological effects in patients than in healthy volunteers.
    

Detailed description: 
      In this study, the investigators aim to assess the effect of acute FODMAP infusion on gastric
      motility and on gastrointestinal and psychological symptoms. This is a randomised,
      single-blinded, crossover study of different solutions, differing in FODMAP content. The four
      solutions that will be tested in healthy volunteers are (1) a fructan solution, (2) a
      fructose solution, (3) a FODMAP mix and (4) a glucose solution as a control. In IBS patients,
      only the fructan and glucose solution will be tested, where after they can choose to come for
      a third visit to test the fructose solution. The different solutions will be tested on
      separate occasions, three days to one week apart, in a randomised order.

      The preparation of each study visit will be identical. After an overnight fast, participants
      will be asked to come to the clinic. To ensure a low baseline symptom level and low microbial
      gut activity, a diet low in fibre and fermentable carbohydrates will be followed the day
      prior to each test (information will be provided to assist this). Participants will be asked
      to refrain from alcohol, tea and coffee, and intense physical activity for at least 12 hours
      before participation. They will also be asked to refrain from smoking cigarettes at least one
      hour before the start of the experiment.

      A high resolution manometry probe will be inserted through the nose into the stomach of the
      participant to assess intragastric pressure as a measure of gastric motility and gastric
      accommodation. In addition, an infusion tube will be positioned in the proximal stomach to
      administer the solution. The position of the probes will be checked fluoroscopically (maximum
      15 seconds). In this case, relevant guidelines of radioprotection will be adhered to.
      Patients will be protected by a lead shield that covers the lower abdomen and all personnel
      will wear a lead jacket. After the catheters are fixed to the subjects' chin, the patients
      will be asked to sit at a table and remain in this position for the remainder of the
      experiment.

      After a stabilization period of at least 15 minutes, and when the subject is in phase II of
      the hunger cycle, one of four solutions will be intragastrically administered at a constant
      speed of 60 mL per minute (determined by an automated system using a peristaltic pump). IGP
      will be recorded for the duration of the drink infusion and for the following 3 hours. During
      infusion, the subjects will be asked to score their satiation at 1-minute intervals using a
      graphic rating scale that combines verbal descriptors on a scale graded of 0-5 (1, threshold;
      5, maximum satiety). The intragastric infusion will be stopped as soon as a score of 5 is
      reached on their satiation scores. In addition, participants will be asked to complete a
      gastrointestinal symptom questionnaire every 15 minutes. The participant's emotions and mood
      will be assessed before, immediately after and 1, 2 and 3 hours after infusion, using the
      State-Trait Anxiety Inventory (STAI) and the validated Dutch version of the Positive and
      Negative Affect Scale (PANAS). Emotional state will be repeatedly measured every 15 minutes
      using the Self-Assessment Manikin (SAM) and Profile of Mood States (POMS)-Fatigue subscale.
    

Intervention name(s): FODMAP; Glucose (control)
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Fermentable oligo-, di- and monosaccharides and polyols are poorly absorbed carbohydrates that are known to cause symptoms in IBS patients.; Glucose is not a FODMAP.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Keywords: FODMAP; Irritable bowel syndrome; Gastric accommodation; Gastric motility; brain-gut axis