Clinical trial NCT06393114: Impacts of Fermented Oat-based Product on Gut Microbiota and Health
Official title: Impacts of Fermented Plant-based Products High in Protein and Fibre on Gut Microbiota and Health: a Randomized, Controlled, Cross-over Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Metabolic Syndrome
Keywords: Fermentation
Plant Proteins, Dietary
Inflammation Mediators
Gastrointestinal Microbiome
Tryptophan
Lead sponsor: University of Eastern Finland
Sponsor class: OTHER
Collaborators: name: University of Turku
name: Umeå University
name: ETH Zurich
name: KU Leuven
First posted: 2024-05-01
Enrollment: 57
Sex: ALL
Minimum age (years): 30
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: During the run-in phase, participants consume their habitual diet. Subsequently, participants are randomized to incorporate one of the study products into their habitual diet for three weeks. The amount of the products to be consumed is 4-6 dl/day, with the precise amount being determined based on the participants' energy requirements. After the three-week diet period, participants will return to their habitual diet, followed by another three-week period during which they will consume the alternate intervention product. The overall duration of the study will be 12 weeks for each participant.
Primary purpose: BASIC_SCIENCE

Brief summary: This study aims to investigate the effects of consuming fermented oat-based products on gut and overall human health. It is a randomized, controlled, cross-over trial with a dietary intervention.

A total of 100 participants will be enrolled in this study and they will eat both fermented and unfermented oat-based products for three weeks. Participants will eat their habitual diet between the dietary intervention periods (wash-out).

During the study, participants' perceived health, inflammatory markers, glucose and lipid metabolism, tryptophan metabolites, gastrointestinal symptoms, and gut microbiota will be assessed.

Detailed description: Plant-based protein sources, such as those derived from oats, are experiencing high demand due to their role in reducing reliance on animal products and promoting a more sustainable food system. Despite this, there is limited information available regarding the impact of components like fibre in plant-based foods on protein and other nutrients' metabolism.

Food fermentation emerges as a potential solution to enhance the absorption of plant-based protein and various nutrients in the small intestine. This is achieved by reducing antinutrients and facilitating the absorption process. Additionally, food fermentation has implications for the composition and metabolic activity of the gut microbiota, influencing metabolism, immune responses, intestinal function, and overall health. The metabolism of tryptophan in the gut, modulated by the gut microbiota and the production of various metabolites, may serve as a key link in these observed effects.

The fermentation of plant-based foods potentially enhances the beneficial health effects of these foods, and investigating this contributes to an increased understanding of the gut-mediated health effects of foods and the mechanisms behind them. This study will be part of a European research project HealthFerm.

Detailed objectives are to:

1. compare fermented and unfermented plant-based food products to blood lipid and glucose metabolism and gastrointestinal comfort as well as perceived and observed overall well-being.
2. study the effects of fermented and unfermented plant-based food consumption on the markers for gut permeability and inflammation.
3. study the difference in microbiota composition and diversity after consuming fermented and unfermented plant-based foods and its contribution to cardiometabolic outcomes.
4. study the difference in microbiota-related metabolites, especially tryptophan metabolites between fermented and unfermented plant-based foods.

A total of 100 participants will be enrolled in this randomized, controlled, cross-over trial, during which they will eat both fermented and unfermented oat-based products as part of their habitual diet. The study follows this sequence:

Weeks 1-3: Habitual diet Weeks 4-6: Dietary Intervention 1 Weeks 7-9: Habitual diet (wash-out) Weeks 10-12: Dietary Intervention 2

Blood, urinary and faecal samples, as well as food diaries and questionnaires, are collected at the end of each study period to assess participants' perceived health, inflammatory markers, glucose and lipid metabolism, tryptophan metabolites, gastrointestinal symptoms, and gut microbiota. In addition, participants' values and attitudes towards fermented foods are assessed. At the end of the study, participants will receive their laboratory results and dietary guidance for their habitual diet from a registered dietitian.

Eligibility criteria: Inclusion Criteria:

* Waist circumference \>90 cm (women) or \>100 cm (men) OR BMI 26-38 kg/m2
* One of the following:

  * raised blood pressure (systolic ≥ 130 mmHg and/or diastolic 85 mmHg)
  * raised fasting plasma glucose (≥ 5.6 mmol/l)
  * raised triglycerides (≥ 1.7 mmol/l)
  * raised total cholesterol (≥ 5 mmol/l)
  * raised LDL (≥ 3 mmol/l)
  * reduced HDL (women \< 1.3 mmol/l, men 1.0 mmol/l)
* Use of cereal products and dairy products or their plant-based alternatives as a part of habitual diet
* Willingness to follow intervention diets for the whole study

Exclusion Criteria:

* Diagnosed chronic diseases and conditions which could hamper the adherence to the dietary intervention protocol, e.g., chronic liver, thyroid, kidney, or gastrointestinal diseases
* Pregnancy and lactation
* Gluten-free or vegan diet
* Recent use of antibiotics (within 3 months)
* Gastrointestinal surgery (within 6 months)
* Alcohol abuse (AUDIT ≥ 15 p and measures of liver function)
* regular smoking or use of snus

Primary outcomes:
measure: Inflammatory marker 1
timeFrame: Weeks 3, 6, 9, and 12
measure: Inflammatory marker 2
timeFrame: Weeks 3, 6, 9, and 12
measure: Inflammatory marker 3
timeFrame: Weeks 3, 6, 9, and 12
Secondary outcomes:
measure: Changes in the composition gut microbiota
timeFrame: Weeks 3, 6, and 12
measure: Glucose metabolism
timeFrame: Weeks 3, 6, 9, and 12
measure: Insulin response
timeFrame: Weeks 3, 6, 9, and 12
measure: Lipid metabolism
timeFrame: Weeks 3, 6, 9, and 12
measure: Tryptophan metabolism
timeFrame: Weeks 3, 6, 9, and 12
measure: Self-reported overall health
timeFrame: Weeks 3, 6, 9, and 12
measure: Self-reported mental health
timeFrame: Weeks 3, 6, 9, and 12
measure: Self-reported gut health
timeFrame: Weeks 3, 6, 9, and 12
measure: Attitudes and values
timeFrame: Weeks 0 and 12
measure: Opinions about the study products
timeFrame: Weeks 6 and 12
Other outcomes:
Locations:
city: Kuopio
country: Finland
facility: University of Eastern Finland
Study officials:
affiliation: Professor
name: Marjukka Kolehmainen
role: PRINCIPAL_INVESTIGATOR
References: