Gut-brain Axis, Brain Function, and Behaviour.

Anxiety Clinical Trial

Official title:

Does Stimulating Friendly Gut Bacteria Improve Brain Function and Behaviour?

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT03554694
• Other study ID #: R52324_RE001
• Status: Recruiting
• Phase: N/A
• Start date: May 6, 2018
• Est. completion date: December 2019

Study information

• Verified date: May 2018
• Source: University of Oxford
• Contact: Gershon Spitz, PhD
• Phone: +44 (0)1865611456
• Email: gershon.spitz[@]ndcn.ox.ac.uk
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 30
• Est. completion date: December 2019
• Est. primary completion date: December 2019
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 50 Years

Eligibility

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.

Related Conditions & MeSH terms

• Anxiety
• Cortisol
• Decision Making
• Emotion
• Humans
• Magnetic Resonance Imaging
• Prebiotics

Intervention

Dietary Supplement:
• Prebiotics
Galactooligosaccharides (GOS) (prebiotics) will be consumed by the participants for 4-6 weeks
• Maltodextrin (placebo)
Maltodextrin (placebo) will be consumed by the participants for 4-6 weeks

Locations

Country	Name	City	State
United Kingdom	University of Oxford	Oxford	Oxfordshire

Sponsors (5)

Lead Sponsor	Collaborator
University of Oxford	Monash University, National Health and Medical Research Council, Australia, Oxford Health Biomedical Research Centre (OH BRC) support scheme, Wellcome Centre for Integrative Neuroimaging

Country where clinical trial is conducted

United Kingdom, 

References & Publications (2)

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. Epub 2006 Sep 6. — View 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. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Cortisol awakening response (CAR)	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)	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).
Primary	Brain imaging (BOLD fMRI activity) in amygdala and cortical regions	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)	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	Changes in gut microbiome	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	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).