Clinical trial NCT04616937: Prebiotics and Mental Health: Behavioural
Official title: The Role of the Microbiota-gut-brain Axis in Brain Development and Mental Health: Behavioural
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Emotion Regulation
Anxiety
Lead sponsor: University of Surrey
Sponsor class: OTHER
Collaborators: name: FrieslandCampina
First posted: 2020-11-05
Enrollment: 64
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 25
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

Brief summary: A behavioural study of the microbiota-gut-brain axis in brain development and mental health

Detailed description: Research suggests that modifying microbial ecology therapeutically via the intake of so-called 'psychobiotics' could help reduce stress responses and symptoms of anxiety and depression (Burnet \& Cowen, 2013; Dinan, Stanton, \& Cryan, 2013; Tang, Reddy, \& Saier, 2014). The term psychobiotics refers to both, beneficial gut bacteria (probiotics), as well as prebiotics, which enhance the growth of beneficial gut bacteria (Sarkar et al., 2016). In a recent study, Schmidt and colleagues explored the effects of prebiotics on the secretion of the stress hormone cortisol and emotional processing in healthy volunteers (Schmidt et al., 2015). They found that cortical awakening response was significantly lower after BimunoÒ-galacto-oligosaccharides (Bimuno) intake over 4 weeks compared with placebo. Moreover, participants exhibited decreased attentional vigilance to negative information in a dot-probe task. Given that anxious people show increased biases towards negative information (Bar-Haim, Lamy, Pergamin, Bakermans-Kranenburg, \& van, 2007), this suggests that prebiotic intake may be useful in modifying anxiety-related cognitive mechanisms.

These findings will be extended to a sample of late adolescents in order to investigate how prebiotic intake for 4 weeks affects cognitive functioning, psychological well-being and gut microbiota a sample of 60 undergraduate students (aged 18-25 years).

At time 1 (pre-assessment), participants in both groups will undergo comprehensive behavioural and psychological testing to establish baseline measures of cognitive functioning and psychological well-being (such as anxiety levels) and asked to collect a stool sample at home for 16s rRNA sequencing of the microbiome. Group 1 will then receive a daily dosage of a galactooligosaccharide (GOS) prebiotic over 4 weeks, whereas group 2 will receive a placebo over the same period. At time 2 (post-assessment), both groups will again undergo cognitive and psychological testing and stool sampling.

Hypothesis: It is predicted that the treatment group (GOS) will show improvements in behavioural indices of emotion regulation (e.g. dot probe task) and in self reported psychological measures related to emotion regulation (e.g. anxiety) in comparison to the placebo group. Changes/differences in gut microbiome samples will be explored.

Eligibility criteria: Inclusion Criteria:

* Females
* Aged between 18-25

Exclusion Criteria:

* Clinical levels of anxiety and/ or co-morbid diagnoses (e.g. depression)
* Current or previous neurological disorders
* Current or previous psychiatric disorders
* Current or previous gastrointestinal disorders
* Current or previous endocrine disorders
* Antibiotic use 3 months prior to the study
* Regular use of pre- and probiotics, including 3 months prior to the study
* Vegan diets
* BMI \>30

Primary outcomes:
measure: Behavioural indices of emotion regulation
timeFrame: 4 weeks
measure: Changes in self reported indices of anxiety.
timeFrame: 4 weeks
measure: Changes in self reported indices of anxiety 2.
timeFrame: 4 weeks
measure: Changes in self reported indices of anxiety 3.
timeFrame: 4 weeks
measure: Changes in self reported emotion regulation (Thought control ability).
timeFrame: 4 weeks
measure: Changes in self reported emotion regulation (Emotion regulation strategies).
timeFrame: 4 weeks
measure: Changes in self reported mood
timeFrame: 4 weeks
measure: Changes in self reported depression.
timeFrame: 4 weeks
Secondary outcomes:
measure: Gut microbiota changes
timeFrame: 4 weeks
Other outcomes:
measure: Exploratory: Changes in nutrient intake and food choice
timeFrame: 4 weeks
Locations:
city: Guildford
country: United Kingdom
facility: University of Surrey
state: Surrey
Study officials:
References: