Impact of Whole Grain Rye Bread on Health

Örebro University, Sweden33 enrolled

Overview

This randomized controlled trial aims to study how a high intake of a fibre-rich bread affects the composition and functioning of the gut microbiota in healthy subjects, and how this, in turn, impacts on the release of gut peptides, intestinal permeability, stress and cognitive performance.

Healthy subjects will be recruited for a 3-week, randomized, parallel-controlled study. Subjects that are eligible to take part in the study will be blinded and randomly allocated to consume a fibre-rich bread or a control bread daily for 3 weeks. Measurements of biomarkers related to the gut-brain axis, microbiota composition and functioning, intestinal permeability, stress and cognitive functioning will be conducted on two separate test days, at baseline and after the 3 weeks intervention. On both test days (day 0 and day 21) subjects will come to the study centre after a 10 hours overnight fast and will deliver faecal samples collected at home. At the study centre, blood samples will be collected and a device for continuous assessment of autonomic nervous system response (Biopac) will be placed. Subjects will drink a multisugar solution and urine samples will be collected for gut permeability analysis. Sugar solution intake will be followed by a baseline period during which participants will rest for 30 minutes to adapt to the laboratory setting. After the baseline period, subjects will conduct a stress test and cognitive tests. Visual analogue scales (VAS) to assess momentary perceived stress levels and saliva samples will be collected before and after the stress test. The study subjects will also complete questionnaires at both visits (food frequency questionnaire, food diary, physical activity, gastrointestinal symptom rating scale, Euro Quality of Life).

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

DOUBLE

Enrollment

Conditions

Healthy Diet

Interventions

Whole grain breadDIETARY_SUPPLEMENT

Consumption of high-fibre bread as a dietary supplementation

Control breadDIETARY_SUPPLEMENT

Consumption of control bread as a dietary supplementation

Eligibility

Sex: ALLMin age: 18 YearsMax age: 44 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Age 18-44 years * Body mass index (BMI) 18,5-30 kg/m2 (normal weight or overweight) Exclusion Criteria: * Significant acute or chronic illness, including an inflammatory or a functional disease of gastrointestinal track and psychiatric and psychological disorders * Anxiety or depression (according to Hospital Anxiety and Depression Scale (HADS score) and Depression Anxiety Stress Scale (DASS-21 score)) * Use of a medication that may interfere with the study (e.g. cannabis, antipsychotics, anxiolytics, antidepressants, proton-pump inhibitors) * Abuse of alcohol or drugs (according to AUDIT score) * Use of antibiotic medication within the past 3 months before the study * Use of laxative or anti-diarrhoea medication within the past 3 months before the study * Regular consumption of probiotic or prebiotic product for the past 6 weeks before the study * A diet that may interfere with the study (such as gluten free or low-carb diet) * Smoking * Pregnancy or breastfeeding * Premenopausal female with irregular or short menstruation cycle and not using hormonal contraception * Colour blindness, dyslexia or dyscalculia * Unable to absent from caffeine, alcohol or intense exercise for 12 hours prior measurements.

Locations (1)

Örebro University

Örebro, Sweden

Outcomes

Primary Outcomes

Microbiota composition baseline vs after intervention using 16S RNA gene sequencing

Difference in gut microbiota composition in faecal samples before (baseline) and after intake of six slices of bread for 3 weeks (after intervention) using 16S RNA gene sequencing

Time frame: faecal samples collected before and after intake of bread for 3 weeks

Secondary Outcomes

Microbiota composition whole grain rye bread vs control bread using 16S RNA gene sequencing

Difference in gut microbiota composition in faecal samples between the study arms using 16S RNA gene sequencing

Time frame: faecal samples collected before and after intake of bread for 3 weeks

Concentrations of circulatory short-chain fatty acids SCFA

Difference in blood levels of SCFA between and within intervention groups after intake of bread for 3 weeks

Time frame: blood samples collected before and after intake of bread for 3 weeks

Concentrations of faecal SCFA

Difference in faecal levels of SCFA between and within intervention groups after intake of bread for 3 weeks

Time frame: faecal samples collected before and after intake of bread for 3 weeks

Concentrations of blood glucagon like peptide-1 (GLP-1)

Difference in blood levels of GLP-1 between and within intervention groups after intake of bread for 3 weeks

Time frame: blood samples collected before and after intake of bread for 3 weeks

Concentrations of blood glucagon like peptide-2 (GLP-2)

Difference in blood levels of GLP-2 between and within intervention groups after intake of bread for 3 weeks

Data from ClinicalTrials.gov

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