Metabolic Syndrome
Conditions
Keywords
Fermentation, Plant Proteins, Dietary, Inflammation Mediators, Gastrointestinal Microbiome, Tryptophan
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.
Interventions
OTHERFermented oat-based product
Participants will incorporate a novel fermented product into their habitual diet for three weeks. In addition, the consumption of dairy and plant-based dairy alternatives is restricted. Cereal product consumption, specifically bread and porridge, is slightly restricted to prevent gastrointestinal symptoms caused by the increased intake of dietary fibre. Participants will receive dietary guidance on how to follow the intervention diet, as well as potential supplement recommendations provided by the authorized nutritionist.
OTHERUnfermented oat-based product
Participants will incorporate a novel unfermented product into their habitual diet for three weeks. Dietary adjustments and other guidance are consistent with those described during the fermented product intervention.
Sponsors
University of Turku
Umeå University
ETH Zurich
KU Leuven
University of Eastern Finland
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
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.
Eligibility
Sex/Gender
ALL
Age
30 Years to 65 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Inflammatory marker 1 | Weeks 3, 6, 9, and 12 | P-hs-CRP (mg/l) |
| Inflammatory marker 2 | Weeks 3, 6, 9, and 12 | IL-22 |
| Inflammatory marker 3 | Weeks 3, 6, 9, and 12 | LBP (μg/ml) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Glucose metabolism | Weeks 3, 6, 9, and 12 | fP-Gluk and B-HbA1C (mmol/l) |
| Insulin response | Weeks 3, 6, 9, and 12 | fP-Insu (mU/l) |
| Lipid metabolism | Weeks 3, 6, 9, and 12 | fP-Kol, fP-Kol-HDL, fP-Kol-LDL, fP-Trigly, and fP-FFA (mmol/l) |
| Opinions about the study products | Weeks 6 and 12 | Unvalidated questionnaire |
| Self-reported overall health | Weeks 3, 6, 9, and 12 | Short Form-36 Health Survey (SF-36). Different sections are rated from 0 to 100 points, where higher scores mean better perceived health. |
| Self-reported mental health | Weeks 3, 6, 9, and 12 | General Health Questionnaire-12 (GHQ-12). The questionnaire is rated from 0 to 12 points, where higher score means greater psychological distress. |
| Self-reported gut health | Weeks 3, 6, 9, and 12 | Gastrointestinal Symptoms Rating Scale (GSRS) |
| Tryptophan metabolism | Weeks 3, 6, 9, and 12 | Tryptophan metabolites will be analysed with non-targeted metabolomics. |
| Attitudes and values | Weeks 0 and 12 | Unvalidated questionnaire |
| Changes in the composition gut microbiota | Weeks 3, 6, and 12 | Composition of gut microbiota will be analysed from faecal samples |
Countries
Finland
Outcome results
None listed