Emotions, Fear, Stress
Conditions
Brief summary
The effects of butyrate on psychobiological processes are examined in a sample of healthy volunteers.
Detailed description
The study is an interventional triple-blind, placebo-controlled, parallel group design with 2 arms (placebo, butyrate). Healthy male participants adhere to a low-fiber diet for the duration of the study (11 days). At the baseline study visit, measurements are taken in the lab, including biological samples and psychophysiological measurements. Participants then consume placebo or butyrate for 1 week and revisit the lab on day 11 for a second measurement of the outcomes of interest. Specifically, we investigate the effect of colonic butyrate administration on affective processing, including stress sensitivity and fear-related processes (e.g. extinction learning). Volunteers also respond to questionnaires in relation to mood and GI symptoms, and provide biological samples (saliva, blood, and faecal samples) for analysis of cortisol levels, circulating short chain fatty acids and serum BDNF, and faecal SCFA, respectively.
Interventions
DIETARY_SUPPLEMENTPlacebo
Cellulose
DIETARY_SUPPLEMENTButyrate
Sodium butyrate
Sponsors
KU Leuven
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, 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
Sex/Gender
MALE
Age
20 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* Male participants * Age range 20-40 years * BMI range 18.5-25 * Dutch or English as native-language
Exclusion criteria
* previous or current neurological, psychiatric, gastrointestinal or endocrine disorders, or other relevant medical history * current or recent regular medication use * previous or current substance/alcohol dependence or abuse (\> 2 units per day/14 units per week) * one or more diagnoses based on the mini-international neuropsychiatric interview * smoking * night-shift work * adherence to vegan or vegetarian diets * use of pre- or probiotics within one month preceding the study * use of antibiotics within 3 months preceding the study * previous experience with one of the tasks used in the study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Stress sensitivity (cortisol) | through study completion, on average 1 year and 5 months | Induction of cognitive, physical, and social stress using Maastricht Acute Stress Test. Stress hormone cortisol is quantified by gathering multiple saliva samples throughout the stress induction and recovery during both pre-intervention and post-intervention visit. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cortisol awakening response | through study completion, on average 1 year and 5 months | Measuring chronic stress by quantifying cortisol in morning samples (5 samples taken form the moment of waking every 15 minutes for 1 hour) on the morning of the pre- and post-intervention visits. |
| Fear | through study completion, on average 1 year and 5 months | Exploring fear-related processes (conditioning, extinction, recall, and renewal) by means of a computerised task. Fear response is measured using skin conductance, and a skin conductance response is calculated. |
| Fear (subjective) | through study completion, on average 1 year and 5 months | Exploring fear-related processes (conditioning, extinction, recall, and renewal) by means of a computerised task. Fear response is measured subjectively by asking participants to indicate their expectancy of an aversive stimulus. |
| Positive and Negative Affect Schedule (PANAS) | through study completion, on average 1 year and 5 months | Assessing ratings on the subscales of PANAS, positive and negative affect. PA subscale scores range between 10-50, with higher scores indicating better outcome. NA subscale scores range between 10-50, with higher scores indicating worse outcome. |
| Perceived Stress Scale (PSS) | through study completion, on average 1 year and 5 months | Assessing ratings on PSS. Scores range between 0-40 with higher scores indicating worse outcome. |
| Stress sensitivity (subjective) | through study completion, on average 1 year and 5 months | Induction of cognitive, physical, and social stress using Maastricht Acute Stress Test. Participant rate how much stress, discomfort, and pain they feel on a 10-cm visual analogue scale, with higher values indicating greater stress, discomfort, and pain. This is done prior to stress induction, in the middle, and at the end at both pre- and post-intervention visits. |
| Leiden Index of Depression Sensitivity-Revised (LEIDS-R) | through study completion, on average 1 year and 5 months | Assessing ratings on the subscales of LEIDS-R and its total score. This is a self-report on cognitive reactivity comprised of 34 items with six subscales. Hopelessness/suicidality; Acceptance/Coping; Aggression; Control/Perfectionism; Risk Aversion; Rumination. |
| Gastrointestinal symptom rating scale (GSRS) | through study completion, on average 1 year and 5 months | Assessing ratings on the subscales of GSRS and its total score. It has 5 subscales (Reflux, Diarrhea, Constipation, Abdominal Pain, and Indigestion Syndrome). Subscale scores range from 1 to 7 and higher scores indicates a worse outcome. |
| Serum SCFA | through study completion, on average 1 year and 5 months | Quantification of serum SCFA (μM) at pre- and post-intervention |
| Faecal SCFA | through study completion, on average 1 year and 5 months | Quantification of faecal SCFA in samples provided at pre- and post-intervention |
| Serum BDNF | through study completion, on average 1 year and 5 months | Quantification of fasting serum BDNF levels (µg/mL) |
| Depression, anxiety, and stress scales (DASS-21) | through study completion, on average 1 year and 5 months | Assessing ratings on the subscales of DASS-21, depression, anxiety, and stress subscales. Higher scores on these subscales indicates a worse outcome. Normal (depression: 0 - 4; anxiety: 0 - 3; stress: 0 - 7), Mild (depression: 5 - 6; axiety: 4 - 5; stress: 8 - 9), Moderate (depression: 7 - 10; anxiety: 6 - 7; stress: 10 - 12), Severe (depression: 11 - 13; anxiety: 8 - 9; stress: 13 - 16), Extremely Severe (depression: 14 +; anxiety: 10 +; stress: 17 +). |
Countries
Belgium
Outcome results
None listed