Microbial Colonization
Conditions
Keywords
Fiber, Fermented food, Immune system, Microbiota
Brief summary
Within the GEEF om je buik study the effects of an 8-week intervention with either a diet rich in fiber or fermented food on the gut microbiota will be investigated.
Detailed description
This study is a randomized controlled trial (RCT) with three intervention groups (high dietary fiber group (HDF), high fermented foods group (HFF), and a control group (CG)). The total duration of the study is 5 months and consists of an 8-week intervention (2-week ramp up period with dietary guidelines, followed by 6-week period with dietary guidelines + additional consumption of study products) and a follow-up after 3 months. In total 147 subjects will be included.
Interventions
DIETARY_SUPPLEMENTWholeFiber
WholeFiberTM is a product with high levels of prebiotic dietary fibers (\ 85%) mainly consisting of inulin, and some pectin, hemi-cellulose and cellulose that is derived from the root vegetable, chicory roots. Fiber guidelines: Subjects receive a booklet with recipes high in fiber. Subjects are recommended to use 2 recipes + 2 snacks per day. Estimated average intake via the recipes in the recipe booklet is 24 grams/day. General guidelines on nutrition and microbiome: Subjects receive a link to a website with general recommendations to positively alter the gut microbiome (website Voedingscentrum and Dutch Digestive Foundation).
DIETARY_SUPPLEMENTKombucha
The kombucha is produced by a minimum three-month long fermentation process. It is a live fermented herbal drink essence, without refined sugar, and an unpasteurized, organic product. Fermented food guidelines: Study participants in the fermented foods arm are asked to use 3 additional servings of fermented food per day, using the fermented food list / recipe booklet. General guidelines on nutrition and microbiome: Subjects receive a link to a website with general recommendations to positively alter the gut microbiome (website Voedingscentrum and Dutch Digestive Foundation).
DIETARY_SUPPLEMENTMaltodextrin DE19/21
Maltodextrin DE19/21 is a digestible carbohydrate, that is completely digested and does not reach the colon, which makes it a suitable placebo dietary compound and the reason why it is frequently used in comparable studies. General guidelines on nutrition and microbiome: Subjects receive a link to a website with general recommendations to positively alter the gut microbiome (website Voedingscentrum and Dutch Digestive Foundation).
Sponsors
Wageningen University and Research
Maag Lever Darm Stichting
Cidrani
WholeFiber
Keep Food Simple
VU University of Amsterdam
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Masking description
This study is partially blinded, study participants in the fiber and fermented group will be informed about their intervention after randomization. However, the control group will remain blind throughout the intervention period. Furthermore, participants are not made aware of the different types of intervention before start or during the intervention period. This is done to prevent any adjustments of their diets based on the advices in the other groups and to ensure that the control group stays blinded.
Intervention model description
The study applies a randomized, parallel design of 8 weeks (+ follow-up after 3 months)
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
* Men and Women, aged ≥18 - ≤70 years; * Being able to read and speak Dutch; * Willing to keep a stable dietary pattern throughout the study, apart from the dietary advice in the study; * Having a smartphone compatible with the Lifedata or PocketQ app to fill out the daily questionnaires.
Exclusion criteria
* Having a disease or medical condition which can influence the study results such as diabetes, cancer, diagnosed irritable bowel syndrome, renal disease, liver enzyme abnormality, malignant neoplasm, or a history of inflammatory diseases (such as multiple sclerosis, rheumatoid arthritis, and inflammatory bowel disease); * Having a history of intestinal surgery that might interfere with study outcomes (this does not include an appendectomy or cholecystectomy); * Average dietary fiber intake of ≥18 gram (women) or ≥22 gram (men) per day, according to the fiber screen questionnaire (see F1 questionnaires); * More than 3 servings of fermented foods per day as assessed with the fermented food frequency questionnaire (see F1 questionnaires); * Having a Body Mass Index (BMI) of ≥ 30 kg/m2 (self-reported); * Currently following a strict diet and unwilling or unable to change; for example, a gluten free diet or a crash diet using meal substitutes; * Specific food allergies that interfere with dietary intervention (for example, gluten, lactose, etc); * Use of prebiotics, probiotics and/or synbiotics (this should be stopped 4 weeks before the start of the study) and use of fiber supplements; * Use of antibiotic treatment less than 3 months before start of the study and/or use of antibiotics during the study; * Use of medication that can interfere with the study outcomes, as judged by the medical supervisor; * Alcoholic use of ≥14 (women) or ≥28 (men) glasses of alcoholic beverages per week; * Use of soft or hard drugs (should be stopped at least 4 weeks before start of the study); * Being pregnant or lactating; * Participation in another clinical trial at the same time; * Student or employee working at either Food, Health and Consumer Research from Wageningen Food and Biobased Research, Microbiology at VU, the MLDS, at WholeFiber, Keep Food Simple or at Cidrani; * Unable to follow or comply to study rules.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Microbiota diversity | Baseline (week 0) | Microbial richness (ASV) using 16s rRNA |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Gut microbiota composition | Baseline (week 0) | 16s rRNA |
| Carbohydrate Active Enzymes (CAZymes) | Baseline (week 0) | Relative abundance of CAZymes using shotgun metagenomic sequencing |
| 92 inflammatory serum proteins | Baseline (week 0) | 92 protein biomarkers proteins associated with inflammatory and immune response processes measured in dried blood spots using the Olink target 96 panels. Expressed as normalized protein expression (NPX). |
| Dietary intake | Baseline (week 0) | Average intake of fiber, fermented foods and macronutrients using the Traqq app |
| Gastrointestinal complaints | Daily during intervention (week 0 - week 8) | Likert-point scale (scores 0 - 10), for bloating, flatulence and abdominal pain. A higher score means more bloating, flatulence and abdominal pain. |
| Stool frequency | Daily during intervention (week 0 - week 8) | Frequency of bowel movement per day |
| Stool consistency | Daily during intervention (week 0 - week 8) | Consistency per stool, based on Bristol Stool Score (type 1 -7). Scores 1-7. A higher score means more loose / watery stool. |
| Abundance of Prevotella | Baseline (week 0) | Based on a faecal smear image, using MicrobeLink tool from HORAIZON (AI, machine learning). |
| Abundance of Bacteroides | Baseline (week 0) | Based on a faecal smear image, using MicrobeLink tool from HORAIZON (AI, machine learning). |
| Ratio of Prevotella/Bacteroides | Baseline (week 0) | Based on a faecal smear image, using MicrobeLink tool from HORAIZON (AI, machine learning). |
| Transit time | Baseline (week 0) | Using blue dye method (two blue muffins) |
| Sleep quality | Baseline (week 0) | Athens insomnia scale. Score range: 0-28 points. Higher score means worse outcome. |
| Digestion associated Quality of Life | Baseline (week 0) | Digestion associated Quality of Life (DQLQ) questionnaire. Score range: 0-9. Higher score indicates worse digestion associated quality of life. |
| Well-being | Baseline (week 0) | World Health Organisation (WHO)-Five Well-Being Index (WHO-5) questionnaire. Raw score ranges from 0-25. Final score is calculated by multiplying the raw score by 4. Final score range 0-100. Higher score indicates better well-being. |
| Subjective health (perception and awareness) | Baseline (week 0) | A 2-item questionnaire, which assesses how healthy participants perceive their own health and diet. Score range: 2 - 14, higher scores mean a higher subjective health |
| Intention to stay healthy (perception + awareness) | Baseline (week 0) | A 3-item questionnaire, which assesses the extent to which participants have the intention to eat healthy. Score range: 3 - 21, higher scores mean more intention to stay healthy |
| Dietary intrinsic motivation (perception + awareness) | Baseline (week 0) | A validated 6-item questionnaire, which assesses whether someone's motivation to eat healthy comes from within a person. Score range: 6 - 42, higher scores mean a higher intrinsic motivation. |
| Dietary self-efficacy (perception + awareness) | Baseline (week 0) | A validated 8-item questionnaire, which assesses the extent to which one feels capable of eating healthy. Score range: 8 - 49, higher scores mean a higher self-efficacy |
| Self-regulation (perception + awareness) | Baseline (week 0) | A 5-item questionnaire, which assesses the ability to plan and monitor actions. Score range: 5 - 35, higher scores mean a higher self-regulation |
| Subjective knowledge (perception + awareness) | Baseline (week 0) | A validated 5-item questionnaire, which assesses how knowledgeable someone feels about nutrition and gut microbiota. Score range: 5 - 35, higher scores mean a higher subjective knowledge |
| Microbial alpha diversity | Baseline (week 0) | Based on a faecal smear image, using MicrobeLink tool from HORAIZON (AI, machine learning). |
Other
| Measure | Time frame | Description |
|---|---|---|
| Body Mass Index (BMI) | Baseline (week 0) | Weight and height will be combined to report BMI in kg/m\^2 |
Countries
Netherlands
Outcome results
None listed