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Brain Responses to Short-Chain Fatty Acid Intervention

Not Applicable
Not yet recruiting
Conditions
Healthy Volunteers
Stress
Interventions
Other: Short-Chain Fatty Acids
Other: Placebo
Registration Number
NCT06546683
Lead Sponsor
Universitaire Ziekenhuizen KU Leuven
Brief Summary

A randomized, triple-blind, placebo-controlled study on the effect of colon-delivered short-chain fatty acids (SCFAs) on neural responses to stress and neuroepigenetics.

Detailed Description

The goal of this interventional study is to study the underlying mechanism of the attenuating effect of colon-delivered SCFAs on the cortisol response to stress. Pre-clinical studies suggest that the histone-deacetylase (HDAC)-inhibiting properties of SCFAs are the main mechanism underlying SCFA-induced changes in stress, cognition and behavior.

Primary objective: to test the effect of colon-delivered SCFA intervention versus placebo on HDAC expression in the brain and neural responses to stress

Secondary objective: to determine the effects of colon-delivered SCFA administration versus placebo on inflammatory and autonomic responses to stress and to determine the mediating and/or moderating factors that potentially underlie SCFA-induced changes to stress responses (HDAC expression in stress-responsive regions, serum SCFA levels)

To this end, 32 participants will be asked to undergo a pre- and post-intervention visit, separated by one week intervention with either colon-delivered SCFAs or placebo (16 per group). During the study visits, participants undergo simultaneous PET-MR imaging with \[11C\]Martinostat. They undergo the Montreal Imaging Stress Test (MIST) and the Maastricht Acute Stress Test (MAST) at each visit.

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
Male
Target Recruitment
32
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. Access to a -18°C freezer (i.e. ordinary household freezer)
  4. Male participants
  5. Age 18-45 years
  6. 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 jeopardise the participant's safety or compliance with the protocol (as assessed by medical staff on the research team)
  3. Any prior or concomitant treatment(s) that might jeopardise the participant's safety or that would compromise the integrity of the study
  4. Participation in an interventional Trial with an investigational medicinal product (IMP) or device
  5. Current or recent (3-month) medication use (especially antibiotics, cardiovascular drugs, steroids, non-steroid anti-inflammatory drugs, centrally effective drugs)
  6. Current or recent (1-month) infection (e.g. common cold, influenza, COVID-19, etc.)
  7. Recent (1-month) vaccination (e.g. flu shot, SARS-COV-2 vaccine, etc)
  8. Smoking
  9. Night-shift work
  10. Adherence to special diets (e.g. vegan, vegetarian, weight-loss, lactose-free, gluten- free, etc.)
  11. Use of pre- or probiotics within one month preceding the study
  12. Previous experience with any of the tasks used in the study (not including questionnaires)
  13. Neuroimaging contraindications
  14. If the participant invokes that he does not want to be informed of eventual pathology that might be found during imaging (invokes the "right not to know")

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Short-Chain Fatty AcidsShort-Chain Fatty AcidsSCFAs will be delivered directly to the colon using pH-dependent colon delivery capsules
PlaceboPlaceboColon-delivery capsules of microcrystalline cellulose
Primary Outcome Measures
NameTimeMethod
HDAC expressionThroughout study completion, on average 2 years

Brain HDAC expression will be quantified using the PET radiotracer \[11C\]Martinostat before and after the intervention

Brain response to stressThroughout study completion, on average 2 years

Brain response (brain oxygenation level-dependent signals) to a fMRI-adapted stress task will be measured before and after intervention

Secondary Outcome Measures
NameTimeMethod
Salivary cortisol response to stressThroughout study completion, on average 2 years

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

C-reactive protein levelsThroughout study completion, on average 2 years

Quantification of hs-C-reactive protein levels (ng/ml) before and after intervention

Brain metabolite concentrationThroughout study completion, on average 2 years

Relative quantification of brain metabolites (mmol/L) using 1H-Magnetic Resonance Spectroscopy before and after intervention

Serum short-chain fatty acid levelsThroughout study completion, on average 2 years

Quantification of serum SCFA (μM) before and after intervention

Heart rate variabilityThroughout study completion, on average 2 years

Assessing heart rate variability (ms) with ECG before and after intervention

Blood pressureThroughout study completion, on average 2 years

Assessing blood pressure (systolic/diastolic mmHg) with a blood pressure monitor before and after intervention

Cytokine levelsThroughout study completion, on average 2 years

Quantification of inflammatory cytokines (pg/ml) before and after intervention

HeartbeatThroughout study completion, on average 2 years

Assessing heartbeat (bpm) with a blood pressure monitor before and after intervention

Self-reported stressThroughout study completion, on average 2 years

Psychological stress sensitivity is measured through 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.

Trial Locations

Locations (1)

UZ/KU Leuven

🇧🇪

Leuven, Belgium

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