Effects of rifaximin on gut bacteria and emotional responses

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This interventional trial investigates how rifaximin, an antibiotic, alters gut microbiota and its subsequent effects on stress sensitivity and fear-related processes in healthy men. Participants will be randomly assigned to receive either rifaximin or a placebo for two weeks, with a focus on understanding the psychobiological changes induced by the treatment. The study employs a triple-blind design to ensure unbiased results, and aims to identify factors that may mediate or moderate these changes.

Why it matters

Who can join: the full rules

Inclusion Criteria:

1. Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures
2. Proficiency in English and/or Dutch
3. Healthy with no intestinal and/or psychological complaints
4. Access to a -18°C freezer (i.e. ordinary household freezer)
5. Male participants
6. Age 18-50 years
7. BMI 18.5-25 kg/m2

Exclusion Criteria:

1. Participant has a history of previous or current neurological, psychiatric, gastrointestinal or endocrine disorder
2. Any disorder, which in the Investigator's opinion might jeopardize the participant's safety or compliance with the protocol
3. Any prior or concomitant treatment(s) that might jeopardize the participant's safety or that would compromise the integrity of the Trial
4. Participation in an interventional Trial with an investigational medicinal product (IMP) or device
5. Hypersensitivity to the active substance rifaximin, to any rifamycin (e.g. rifampicin or rifabutin) or any of the excipients
6. Current or recent medication use
7. Use of antibiotics within three months preceding the study
8. Current or recent (1-month) infection (e.g. common cold, influenza, COVID-19, etc.)
9. Previous or current substance/alcohol dependence or abuse (\>2 units per day or 14 units per week)
10. One or more diagnoses based on the mini international neuropsychiatric interview (MINI-S)
11. One or more diagnoses based on ROME IV for gastrointestinal disorders
12. Smoking
13. Night-shift work
14. Adherence to special diets (e.g. vegan, vegetarian, weight-loss, lactose-free, gluten-free, etc.)
15. Use of pre- or probiotics within one month preceding the study
16. Previous experience with any of the tasks used in the study (not including questionnaires)
17. Color vision deficiency (colorblindness)
18. 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.

Where it's running

• UZ/KU Leuven
  Leuven, Belgium Recruiting

Study contacts

• Principal investigator: Lukas Van Oudenhove, MD, PhD — KU Leuven
• Study coordinator: Lukas Van Oudenhove, MD, PhD
• Email: lukas.vanoudenhove@kuleuven.be
• Phone: +32 16 33 01 47

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Using VR headsets or play cards to ease fear during inhaler treatment for kids

  This trial tests whether virtual reality or interactive distraction cards help 4–6 year-olds feel less fear and anxiety when receiving inhaler medication.

  Recruiting Bandırma Onyedi Eylül University · Balıkesir, Balıkesir · NCT07780331

• Distraction Methods to Ease Pain and Fear During a Child’s Blood Draw

  This study tests if pinwheel blowing, a 3D hologram, or sugar-free gum can reduce pain and fear during blood draws for kids aged 5–10 compared with routine procedure.

  Recruiting Corlu State Hospital · Tekirdağ · NCT07770191

• Using a stress ball or cartoons to ease fear, anxiety, and pain during skin prick tests in kids

  This trial tests whether watching cartoons or using a stress ball helps 4- to 10-year-olds handle skin prick allergy testing better than usual care.

  Recruiting Tarsus University · Tarsus · NCT07750236

• Two Different Therapeutic Distractions Used During Blood Draw for Children Aged 5–7

  This study tests whether two distraction methods during blood sampling can reduce pain, fear, and anxiety in 5–7 year-olds compared with routine care.

  Recruiting Phase 1 Igdir University · Iğdır, Iğdır · NCT07731347

• VR preparation for kids before surgery

  A small study tests whether a virtual reality tour of the hospital before surgery helps kids aged 3–12 feel less anxious and more cooperative.

  Recruiting Fundación de investigación HM · Madrid, Mujer · NCT07650695

• Rhythmic Skin Tapping and Internal Vibration for Pediatric Venipuncture Pain and Fear

  This study tests whether light fingertip tapping above the needle site or a humming sound can reduce pain and fear in children aged 6-12 during blood draws.

  Recruiting Akdeniz University · Antalya, Kepez · NCT07650591

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.