Clinical trial NCT03554694: Gut-brain Axis, Brain Function, and Behaviour.
Official title: Does Stimulating Friendly Gut Bacteria Improve Brain Function and Behaviour?
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Prebiotics
Anxiety
Humans
Magnetic Resonance Imaging
Decision Making
Emotion
Cortisol
Lead sponsor: University of Oxford
Sponsor class: OTHER
Collaborators: name: National Health and Medical Research Council, Australia
name: Oxford Health Biomedical Research Centre (OH BRC) support scheme
name: Wellcome Centre for Integrative Neuroimaging
name: Monash University
First posted: 2018-06-13
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
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.
Primary purpose: BASIC_SCIENCE

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.


Eligibility 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.

Primary outcomes:
measure: Cortisol awakening response (CAR)
timeFrame: 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).
measure: Brain imaging (BOLD fMRI activity) in amygdala and cortical regions
timeFrame: 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).
Secondary outcomes:
measure: Changes in gut microbiome
timeFrame: 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).
Other outcomes:
Locations:
city: Oxford
country: United Kingdom
facility: University of Oxford
state: Oxfordshire
Study officials:
affiliation: University of Oxford
name: Jacinta O'Shea, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Schmidt K, Cowen PJ, Harmer CJ, Tzortzis G, Errington S, Burnet PW. Prebiotic intake reduces the waking cortisol response and alters emotional bias in healthy volunteers. Psychopharmacology (Berl). 2015 May;232(10):1793-801. doi: 10.1007/s00213-014-3810-0. Epub 2014 Dec 3.
citation: Bishop SJ, Jenkins R, Lawrence AD. Neural processing of fearful faces: effects of anxiety are gated by perceptual capacity limitations. Cereb Cortex. 2007 Jul;17(7):1595-603. doi: 10.1093/cercor/bhl070. Epub 2006 Sep 6.