Gastrointestinal Diseases, Cardiovascular Diseases, Obesity
Conditions
Brief summary
A dietary intervention study designed as a randomized, controlled, parallel intervention of 6-weeks duration. A total of 75 participants will be included in the study and randomly allocated to one of three interventions (refined wheat, whoelgrain wheat or wholegrain rye). Clinincal examinations including anthropometric assessment, fecal, urine and fastign blood sampling, dietary assessment and a meal challenge will be done before (week 0) and after (week 6) the intervention. At timepoints week 0, 2, 4 and 6 questionnaires will be filled in concerning satisfaction with diet and gastrointestinal symptoms.
Detailed description
A dietary intervention study designed as a randomized, controlled, parallel intervention of 6-weeks duration. A total of 75 participants will be included in the study and randomly allocated to one of three interventions (refined wheat, whoelgrain wheat or wholegrain rye). The randomization will be stratified according to sex and sex-specific median habitual cereal dietary fibre intake (16g/d for men and 13g/d for women). The randomization will be done by means of a randomization generator of the webpage (http://www.randomization.com). Recruitment and randomization will take place continuously during the study period, and therefore randomization will be done as mixed block randomization. During the intervention study, participants are instructed to substitute all cereal products (e.g. bread, breakfast cereals, pasta) of their diet with the provided study products. The amount of provided study products will match the average intake of carbohydrate-rich products of the Danish population, which corresponds to \ 200g of bread and cereal products per day. The participants will eat the study products in an ad libitum manner and b instructed to avoid other cereals in their diet including cake, biscuits, ready made meals and fast foods with the exception of White rice whis is allowed 1-2 times per week. Clinincal examinations including anthropometric assessment, fecal, urine and fastign blood sampling, dietary assessment and a meal challenge will be done before (week 0) and after (week 6) the intervention. At timepoints week 0, 2, 4 and 6 questionnaires will be filled in concerning satisfaction with diet and gastrointestinal symptoms.
Interventions
OTHERWholegrain rye
A variety of cereal foods providing \>100g/day wholegrain from rye
OTHERWholegrain wheat
A variety of cereal foods providing \>100g/day wholegrain from wheat
OTHERRefined wheat
A variety of cereal foods providing 0g/day wholegrain
Sponsors
Lantmännens Forskningsstiftelse
University of Copenhagen
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
30 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* • Age: 30 - 65 years * Body mass index (BMI): 25 - 32 kg/m2 * Weight stable (\<3 kg weight change during the last 6 months) * Apparently healthy * Informed consent signed * Freezer capacity for 2 weeks bread provision * Can attend all visits required for the study
Exclusion criteria
* • Smoking on a daily basis * Lactating (or lactating within 6 weeks prior to study start), pregnant (or pregnant within 3 months prior to study start) or wish to become pregnant during the study * Diagnosed with any form of diabetes or CVD * Reported chronic GI disorders * Antibiotic treatment 3 month before study start and during the study * Use of pre- or probiotic 1 month before study start and during the study * Lack of cooperation and adherence to the protocol * Use of prescription medication will be evaluated on an individual basis
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Gastrointestinal symptoms evaluated by questionnaires (100mm visual analogue scales) | Change from 0 to 6 weeks | Subjective sensations of gastrointestinal symptoms evaluated by questionnaires (100mm visual analogue scales) |
| Gut microbiota composition assessed using 16S in a single fecal sample | Change from 0 to 6 weeks | Gut microbiota compostion assessed using 16S in a single fecal sample |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Anthropometric masures | Change from 0 to 6 weeks | Body weight and waist circumference, saggital abdominal diameter and body composition (fat mass and fat free mass assessed using DEXA) |
| Blood pressure | Change from 0 to 6 weeks | Diastolic and systolic blood pressure and heart rate assessed twice using an automated apparatus |
| Blood lipids, fasting concentrations of total, LDL and HDL cholesterol and triglyerides | Change from 0 to 6 weeks | Fasting concentrations of total, LDL and HDL cholesterol and triglyerides |
| Glucose metabolism, fasting concentrations of glucose, insulin and HbA1C as calculation of HOMA-IR | Change from 0 to 6 weeks | Fasting concentrations of glucose, insulin and HbA1C as calculation of HOMA-IR |
| Breath hydrogen assessed using a Hydrolyzer | Change from 0 to 6 weeks | Fasting and postprandial (every 30 minutes for 240 minutes) concentrations of H2 in exhaled breath assessed using a Hydrolyzer |
| Low-grade inflammation, fasting concentrations of hsCRP, IL-6, IL-10, and TNF-a | Change from 0 to 6 weeks | Fasting concentrations of hsCRP, IL-6, IL-10, and TNF-a |
| Fecal pH | Change from 0 to 6 weeks | Fecal pH assessed in homogenized fecal sample |
| Intestinal permeability, assessed by urinary excretion of lactulose and mannitol | Change from 0 to 6 weeks | Intestinal permeability is assessed by urinary excretion of lactulose and mannitol for 4 hours and 24 hours following an oral load of 10g lactulose and 2 g mannitol |
| Zonulin, fasting concentrations in plasma | Change from 0 to 6 weeks | Fasting concentrations of zonulin in plasma |
| Dietary intake, a weighted 4-day food record | Change from 0 to 6 weeks | a weighted 4-day food record will be used to assess energy intake and macronutrient (protein, fat, carbohydrates and dietaru fiber) composition |
| Compliance, measured by fasting plasma alkylresorcinol concentrations will be used as a biomarker of wholegrain wheat and rye intake | Change from 0 to 6 weeks | Fasting plasma alkylresorcinol concentrations will be used as a biomarker of wholegrain wheat and rye intake |
| Short chain fatty acids, fecal concentrations of short chain fatty acids | Change from 0 to 6 weeks | Fecal concentrations of short chain fatty acids |
| Appetite sensation | Change from 0 to 6 weeks | Fasting and postprandial (every 30 minutes for 240 minutes) sensation of hunger, satiety, fullness, prospective food intake, thirst and well being |
Outcome results
None listed