Cognitive and Metabolic Effects of a Probiotic Supplement

N/AUnknownNCT02005003

Uppsala University20 enrolled

Overview

To examine the cognitive and metabolic effects of a probiotic supplement that is readily and already available for purchase in public drug stores. This study is a double-blinded randomized cross-over placebo-controlled intervention study. Participants will be randomized to receive either the probiotic supplement or the placebo during the first intervention period which will last 2 weeks. This will be followed by a washout period, after which they will proceed to the second intervention period, also lasting 2 weeks and also followed by a washout period.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

DOUBLE

Enrollment

Conditions

Dietary Supplements Probiotics Metabolism Food Preferences Microbiota

Interventions

Inhibitory taskBEHAVIORAL

Participants perform a binary decision on each presented stimuli. Of the two possible outcomes, participants are instructed to make a motor response (go) for one type, and are to withhold a response (no-go) for the other type. Reaction time and accuracy are measured for each event

Blood samplesPROCEDURE

Hormone levels will be analyzed from blood samples obtained before and after a caloric preload given at each visit

Feces collectionBIOLOGICAL

Feces samples will be collected on the morning of each visit, before and after each 2-week intervention period, as well as after each 2-week washout period following each intervention period.

Caloric preloadPROCEDURE

A caloric preload will be given to participants, following which blood will be taken at 65 minutes later (specified in Blood sampling) following the ingestion of the caloric preload.

Food selection taskBEHAVIORAL

Participants are given the opportunity to write and use a computer program to specify amount and type of food would ideally like to consume

Memory taskBEHAVIORAL

Participants perform short memory tasks on each visit

Food consumption taskBEHAVIORAL

Participants are given a selection of food items to consume on each visit

Eligibility

Sex: MALEMin age: 18 YearsMax age: 28 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Male * Age 18-28y * Healthy (self-reported) and not on medication * Non-smoking * Normal sleep-wake rhythm (i.e. 7-8 h per night, self-reported via diaries) * Regular meal patterns with daily breakfast Exclusion Criteria: * Major illness * Taking any serious medications * Any sleep conditions (e.g. irregular bedtimes, sleep complaints) * Any dietary issues with the food items provided * Current or history of endocrine, neurological or psychiatric disorders * Shift work in the preceding three months or for a long duration * Time travel over a significant number of time zones in the preceding two months * Too much weight gain or weight loss in the preceding three months * Excessive intake of fermented dairy products * Intake of probiotics * Recent antibiotic treatment (last 6 months) * Recent intake of certain dietary supplements * Excessive caffeine (\>5 cups daily) or alcohol intake (\>2 alcohol units daily)

Outcomes

Primary Outcomes

Memory function

Memory test to examine the influence of probiotic supplement compared with placebo on memory function (declarative and working memory)

Time frame: Change in memory function assessed at baseline (week 0), post-intervention 1 (at week 2), pre intervention 2 (week 6), post intervention 2 (week 8) and post-washout intervention 2 (week 12)

Secondary Outcomes

Glycometabolic regulation

Glucose, insulin and other hormonal values during fasting and 1 hour following a standardized caloric preload

Time frame: Change in glycometabolic regulation assessed at baseline (week 0), post-intervention 1 (at week 2), pre intervention 2 (week 6), post intervention 2 (week 8) and post-washout intervention 2 (week 12)

Food preferences

Will test whether participants food preferences are changed following each intervention, as compared with before each intervention. Test will be written and computer-based.

Time frame: Change in food preferences assessed at baseline (week 0), post-intervention 1 (at week 2), pre intervention 2 (week 6), post intervention 2 (week 8) and post-washout intervention 2 (week 12)

Inhibitory task

Time frame: Change in inhibitory task performance assessed at baseline (week 0), post-intervention 1 (at week 2), pre intervention 2 (week 6), post intervention 2 (week 8) and post-washout intervention 2 (week 12)

Food consumption task

Participants will be offered a food selection and their consumption will be measured.

Time frame: Change in food consumption task assessed at baseline (week 0), post-intervention 1 (at week 2), pre intervention 2 (week 6), post intervention 2 (week 8) and post-washout intervention 2 (week 12)

Sleep patterns

Time frame: Change in sleep patterns as assessed at baseline (week 0), post-intervention 1 (at week 2), pre intervention 2 (week 6), post intervention 2 (week 8) and post-washout intervention 2 (week 12)

Microbiome changes

Changes in microbiome will be assessed following treatment with either placebo or probiotics; feces will be collected according to standardized criteria.

Time frame: Microbiome assessed at baseline (week 0), post-intervention 1 (at week 2), pre intervention 2 (week 6), post intervention 2 (week 8) and post-washout intervention 2 (week 12)