A Randomized, Triple-blind, Placebo-controlled Study on the Effect of Rifaximin on Psychobiological Functions in Healthy Men
Trial Snapshot
- Phase
- Phase 2
- Status
- Recruiting
- Enrollment
- 60
- Locations
- 1
- Primary Endpoint
- Fear (biological)
Study Overview
Brief Summary
A randomized, triple-blind, placebo-controlled study on the effect of rifaximin on psychobiological functions in healthy men.
Detailed Description
This study is a randomized, triple-blind, placebo-controlled, interventional trial aiming to elucidate the impact of rifaximin-induced gut microbiota alteration to the psychobiological functioning of healthy men. The intervention will be performed in a parallel group design where one group will receive rifaximin (Targaxan 550 mg) twice daily for two weeks (treatment arm), while the other group will receive placebo (placebo arm).
Primary objective: to test the effect of rifaximin on stress sensitivity and fear-related processes
Secondary objective: to determine the mediating and/or moderating factors that underlie rifaximin-induced psychobiological changes
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Basic Science
- Masking
- Triple (Participant, Investigator, Outcomes Assessor)
Masking Description
Participants, investigators, and personnel involved in data analyses are blinded to the intervention. Unblinding occurs after all data has been collected and analysed.
Eligibility Criteria
- Ages
- 18 Years to 50 Years (Adult)
- Sex
- Male
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures
- •Proficiency in English and/or Dutch
- •Healthy with no intestinal and/or psychological complaints
- •Access to a -18°C freezer (i.e. ordinary household freezer)
- •Male participants
- •Age 18-50 years
- •BMI 18.5-25 kg/m2
Exclusion Criteria
- •Participant has a history of previous or current neurological, psychiatric, gastrointestinal or endocrine disorder
- •Any disorder, which in the Investigator's opinion might jeopardize the participant's safety or compliance with the protocol
- •Any prior or concomitant treatment(s) that might jeopardize the participant's safety or that would compromise the integrity of the Trial
- •Participation in an interventional Trial with an investigational medicinal product (IMP) or device
- •Hypersensitivity to the active substance rifaximin, to any rifamycin (e.g. rifampicin or rifabutin) or any of the excipients
- •Current or recent medication use
- •Use of antibiotics within three months preceding the study
- •Current or recent (1-month) infection (e.g. common cold, influenza, COVID-19, etc.)
- •Previous or current substance/alcohol dependence or abuse (>2 units per day or 14 units per week)
- •One or more diagnoses based on the mini international neuropsychiatric interview (MINI-S)
- •One or more diagnoses based on ROME IV for gastrointestinal disorders
- •Night-shift work
- •Adherence to special diets (e.g. vegan, vegetarian, weight-loss, lactose-free, gluten-free, etc.)
- •Use of pre- or probiotics within one month preceding the study
- •Previous experience with any of the tasks used in the study (not including questionnaires)
- •Color vision deficiency (colorblindness)
- •Magnetic Resonance Imaging (MRI) contraindications, including claustrophobia, severe back problems, conditions that would interfere with MRI scanning (e.g. cochlear implant, metal fragments in eyes, metallic body inclusion, or other metal implanted in the body), and if the participant does not want to be informed of incidental findings that might be found during imaging.
Arms & Interventions
Rifaximin
Rifaximin oral tablets, 550 mg, twice daily, two-weeks
Intervention: Rifaximin (Drug)
Placebo
Placebo oral tablets, twice daily, two-weeks
Intervention: Placebo (Dietary Supplement)
Outcomes
Primary Outcomes
Fear (biological)
Time Frame: Throughout study completion, on average 1 year
Fear-related processes will be explored using a computerized task. Biological fear response is measured using skin conductance, and a skin conductance response (μS) is calculated .
Fear (psychological)
Time Frame: Throughout study completion, on average 1 year
Fear-related processes will be explored using a computerized task. Psychological fear response is measured subjectively by asking participants to indicate their expectancy score of an aversive stimulus.
Stress sensitivity (biological)
Time Frame: Throughout study completion, on average 1 year
Biological stress sensitivity is measured by quantifying cortisol levels (ng/ml) from multiple saliva samples taken before, during, and after a stress task performed during the pre-intervention and post-intervention visit.
Stress sensitivity (psychological)
Time Frame: Throughout study completion, on average 1 year
Psychological stress sensitivity is measured through subjective stress reports of the participants using the visual analogue scale (VAS). VAS scorings are taken before, during, and after a stress task performed during the pre-intervention and post-intervention visit.
Secondary Outcomes
- Gastrointestinal Symptom Rating Scale (GSRS)(Throughout study completion, on average 1 year)
- Brain response to stress(Throughout study completion, on average 1 year)
- Positive and Negative Affect Schedule (PANAS)(Throughout study completion, on average 1 year)
- Perceived Stress Scale (PSS)(Throughout study completion, on average 1 year)
- Leiden Index of Depression Sensitivity (LEIDS-R)(Throughout study completion, on average 1 year)
- State-Trait Anxiety Inventory, State Anxiety Subscale (STAI-S)(Throughout study completion, on average 1 year)
Investigators
Lukas Van Oudenhove
Principal Investigator
Universitaire Ziekenhuizen KU Leuven