Gut Health Enhancement by Eating Favourable Food

Not Applicable

Active, not recruiting

• Conditions: Microbial Colonization
• Interventions: Dietary Supplement: WholeFiber; Dietary Supplement: Maltodextrin DE19/21; Dietary Supplement: Kombucha

• Registration Number: NCT05900609
• Lead Sponsor: VU University of Amsterdam

Brief Summary

Within the GEEF om je buik study the effect of 8 weeks 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.

Study Timeline

• Study First Submitted: 2023-04-03
• Study Start: 2023-05-22
• Study First Submitted QC: 2023-06-09
• Study First Posted: 2023-06-12
• Status Verified: 2023-09
• Primary Completion: 2023-11-26
• Last Update Submitted: 2024-01-09
• Last Update Posted: 2024-01-10
• Study Completion: 2024-03-05

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 146

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Fiber arm	WholeFiber	Subjects receive dietary guidelines, to increase their fiber intake. Additionally, during the last 6 weeks of the intervention period subjects receive a study product containing 8,5 grams fiber per day. Additionally, subjects receive general guidelines about the effect of nutrition on the gut microbiome.
Control	Maltodextrin DE19/21	Subjects receive general guidelines about the effect of nutrition on the gut microbiome. Additionally, during the last 6 weeks of the intervention period subjects receive a placebo product of 10 grams maltodextrin per day.
Fermented food arm	Kombucha	Subjects receive dietary guidelines, to increase their intake of fermented foods. Additionally, during the last 6 weeks of the intervention period subjects receive a study product of 17 millilitres concentrated kombucha per day. Additionally, subjects receive general guidelines about the effect of nutrition on the gut microbiome.

Primary Outcome Measures

Name	Time	Method
Microbiota diversity	End intervention (week 8)	Microbioal richness (ASV) using 16s rRNA

Secondary Outcome Measures

Name	Time	Method
Gut microbiota composition	End intervention (week 8)	16s rRNA
Dietary intake	End follow-up (5 months)	Average intake of fiber, fermented foods and macronutrients using the Traqq app
Stool frequency	Daily during intervention (week 0 - week 8)	Frequency of bowel movement per day
Abundance of Prevotella	End intervention (week 8)	Based on a faecal smear image, using MicrobeLink tool from HORAIZON (AI, machine learning).
Ratio of Prevotella/Bacteroides	End intervention (week 8)	Based on a faecal smear image, using MicrobeLink tool from HORAIZON (AI, machine learning).
Well-being	End follow-up (5 months)	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.
Carbohydrate Active Enzymes (CAZymes)	End intervention (week 8)	Relative abundance of CAZymes using shotgun metagenomic sequencing
92 inflammatory serum proteins	End intervention (week 8)	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).
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.
Intention to stay healthy (perception + awareness)	End follow-up (5 months)	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
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 Bacteroides	End intervention (week 8)	Based on a faecal smear image, using MicrobeLink tool from HORAIZON (AI, machine learning).
Microbial alpha diversity	End intervention (week 8)	Based on a faecal smear image, using MicrobeLink tool from HORAIZON (AI, machine learning).
Transit time	End intervention (week 8)	Using blue dye method (two blue muffins)
Sleep quality	End follow-up (5 months)	Athens insomnia scale. Score range: 0-28 points. Higher score indicates worse sleep quality.
Digestion associated Quality of Life	End follow-up (5 months)	Digestion associated Quality of Life (DQLQ) questionnaire. Score range: 0-9. Higher score indicates worse digestion associated quality of life.
Dietary intrinsic motivation (perception + awareness)	End follow-up (5 months)	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)	End follow-up (5 months)	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
Subjective health (perception and awareness)	End follow-up (5 months)	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
Self-regulation (perception + awareness)	End follow-up (5 months)	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)	End follow-up (5 months)	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

Trial Locations

Locations (1)

Stichting Wageningen Research; 🇳🇱 Wageningen, Gelderland, Netherlands