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Gut-brain Axis, Brain Function, and Behaviour.

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ClinicalTrials.gov Identifier: NCT03554694
Recruitment Status : Recruiting
First Posted : June 13, 2018
Last Update Posted : June 13, 2018
Sponsor:
Collaborators:
National Health and Medical Research Council, Australia
Oxford Health Biomedical Research Centre (OH BRC) support scheme
Wellcome Centre for Integrative Neuroimaging
Monash University
Information provided by (Responsible Party):
University of Oxford

Brief Summary:
The aim is to test if dietary supplementation with prebiotics reduces measures of anxiety in healthy human participants with high self-reported levels of anxiety. Study will test for an effect on behavioural, neuroendocrine and brain imaging markers of anxiety.

Condition or disease Intervention/treatment Phase
Prebiotics Anxiety Humans Magnetic Resonance Imaging Decision Making Emotion Cortisol Dietary Supplement: Prebiotics Dietary Supplement: Maltodextrin (placebo) Not Applicable

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 30 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Intervention Model Description: Crossover Assignment Randomised Double-blind Cross-over design with 4-6 weeks of prebiotics intervention and 4-6 weeks of placebo intervention. The first intervention phase will be followed by a 3 week wash-out period prior to the second intervention phase.d.
Masking: Double (Participant, Investigator)
Masking Description: Both intervention and placebo products are similar in colour, texture, and taste. A third party, independent of the daya-to-day research coordinator, will randomise treatments.
Primary Purpose: Basic Science
Official Title: Does Stimulating Friendly Gut Bacteria Improve Brain Function and Behaviour?
Actual Study Start Date : May 6, 2018
Estimated Primary Completion Date : December 2019
Estimated Study Completion Date : December 2019

Arm Intervention/treatment
Experimental: Start with prebiotics
Half of the participants start with prebiotics, followed by a testing period. After a wash-out period they will continue with placebo followed by a testing period.
Dietary Supplement: Prebiotics
Galactooligosaccharides (GOS) (prebiotics) will be consumed by the participants for 4-6 weeks

Experimental: Start with placebo
Half of the participants start with placebo, followed by a testing period. After a wash-out period they will continue with prebiotics followed by a testing period.
Dietary Supplement: Maltodextrin (placebo)
Maltodextrin (placebo) will be consumed by the participants for 4-6 weeks




Primary Outcome Measures :
  1. Cortisol awakening response (CAR) [ Time Frame: Cortisol awakening responses will be measured at the end of the first intervention phase (4-6 weeks after study entry) and at the end of the second intervention phase (11-15 weeks post study entry). ]
    CAR, a marker of stress responsivity, should be decreased after taking prebiotics compared to placebo (as previously found in non-anxious participants in Schmidt et al., 2015, Psychopharmacology)

  2. Brain imaging (BOLD fMRI activity) in amygdala and cortical regions [ Time Frame: Brain imaging will be measured at the end of the first intervention phase (4-6 weeks after study entry) and at the end of the second intervention phase (11-15 weeks post study entry). ]
    Brain imaging (BOLD fMRI activity) in amygdala and cortical regions Will provide neural measures of threat reactivity. We predict decreased amygdala and/or increased parietal-prefrontal brain activity after prebiotics compared to placebo, indicating an anxiolytic-like profile (fearful -neutral face trials in the low load condition) (as in Bishop et al, 2007 and Ironside et al, 2017)


Secondary Outcome Measures :
  1. Changes in gut microbiome [ Time Frame: Changes in the microbiome will be measure using a single stool/faecal sample at four time points: baseline (0 weeks), following first intervention (4-6 weeks), following washout (7-9 weeks), and following the second intervention (11-15 weeks). ]
    Availability of specific bacteria in microbiome will change as function of prebiotics and not during placebo. The change will be measured at the start of each intervention compared to the end of each intervention



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Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Trait anxiety levels > 40 on STAI trait inventory
  • Participant is willing and able to give informed consent for participation in the study
  • Not currently taking any psychoactive medications

Exclusion Criteria:

  • Pregnant participants
  • No contraindications to prebiotic administration
  • Antibiotic, probiotics and/or prebiotic treatment in at least the two previous months.
  • Participants who are taking any other food supplements that, in the opinion of the Investigators, may affect the results.
  • Participants who are taking any medications that, in the opinion of the Investigators, may affect the results.
  • Any significant change in diet which, at the discretion of the Investigators, may affect the results.
  • Participants who have recently participated in another research trial which, at the discretion of the Investigators, may affect the results.
  • A history of dementia, traumatic brain injury or stroke.
  • Anyone who is unable to perform the behavioural tasks.
  • Current use of any psychoactive medication.
  • Current use of psychological treatment.
  • Anyone who does not have adequate understanding of English, sufficient to give informed consent.
  • Any person who has a history of drug abuse or a previous history of a neurological, or has a history of neurosurgical procedure is excluded as they may be at increased risk of epilepsy and data collected may be influenced by their condition.
  • Anyone with any metal implants or implantable device would be excluded from any brain imaging studies as indicated by the MRI safety screening form.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03554694


Contacts
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Contact: Gershon Spitz, PhD +44 (0)1865611456 gershon.spitz@ndcn.ox.ac.uk

Locations
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United Kingdom
University of Oxford Recruiting
Oxford, Oxfordshire, United Kingdom, OX3 9DU
Contact: University o Oxford    07438239953    gershon.spitz@ndcn.ox.ac.uk   
Sponsors and Collaborators
University of Oxford
National Health and Medical Research Council, Australia
Oxford Health Biomedical Research Centre (OH BRC) support scheme
Wellcome Centre for Integrative Neuroimaging
Monash University
Investigators
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Principal Investigator: Jacinta O'Shea, PhD University of Oxford

Publications:
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Responsible Party: University of Oxford
ClinicalTrials.gov Identifier: NCT03554694     History of Changes
Other Study ID Numbers: R52324_RE001
First Posted: June 13, 2018    Key Record Dates
Last Update Posted: June 13, 2018
Last Verified: May 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Plan Description: The study staff will ensure that the participants' data are safeguarded. The study will comply with the Data Protection Act, which requires personal data to be anonymised as soon as it is practical to do so. Students and collaborators may be given access to fully anonymized data under the supervision of the named investigators. Some peer-reviewed journals require submission of anonymised data that may also be uploaded to other data sharing initiatives. Access may be given to responsible members of the University of Oxford for the purposes of monitoring or audit. The participants' consent will be sought if this is to occur.

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No