Impacts of Fermented Pea- and Legume-based Product on Gut Microbiota and Health (HealthFerm)

Impacts of Fermented Pea- and Legume-based Product High in Protein on Gut Microbiota and Health: a Randomized, Single-blinded, Controlled, Cross-over Trial

This study aims to investigate the effects of consuming fermented pea- and legume-based product on gut and overall human health. It is a randomized, single-blinded, 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 pea- and legume-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.

Study Overview

• Status: Completed
• Conditions: Metabolic Syndrome
• Intervention / Treatment: Other: Fermented meat alternative; Other: Unfermented meat alternative

Detailed Description

Plant-based protein sources, such as those derived from peas and legumes, 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. In addition, the evidence of the health effects of meat alternatives is still scarce.

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 health effects.

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

Detailed objectives are to:

1. compare fermented and unfermented pea- and legume-based food products on 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 pea- and legume-based food consumption on gut permeability and inflammation markers.
3. study the difference in microbiota composition, diversity, and its contribution to cardiometabolic outcomes after consuming fermented and unfermented pea- and legume-based food products .
4. study the difference in microbiota-related metabolites, especially tryptophan metabolites, between fermented and unfermented pea- and legume-based food products.

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

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

Fasting blood, urinary and faecal samples, as well as food diaries and questionnaires, are collected at the end of each study period to assess participants' diet, perceived health, gastrointestinal symptoms, inflammatory markers, glucose and lipid metabolism, tryptophan metabolites, and gut microbiota composition and their metabolites, such as short-chain fatty acids. 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.

• Study Type: Interventional
• Enrollment (Actual): 56
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Finland
  • Kuopio, Finland, 70110
    • Institute of Public Health and Clinical Nutrition, University of Eastern Finland

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Waist circumference >90 cm (women) or >100 cm (men) OR BMI 27-35 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)
• Consumption of at least one meal where the main protein source is meat, fish, or meat alternative on most days
• 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., type 1 or 2 diabetes, 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 or nicotine bags

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Habitual diet; Participants consume their habitual diet without any intervention products.
Experimental: Fermented product; Participants consume a fermented pea- and legume-based product daily for three weeks within their diet.	Other: Fermented meat alternative; Participants incorporate a novel fermented product into their habitual diet for three weeks. The product replaces the main protein source of the meal(s). Participants will receive dietary guidance on how to follow the intervention diet, as well as potential supplement recommendations provided by the authorized nutritionist.
Active Comparator: Unfermented product; Participants consume an unfermented pea- and legume-based product daily for three weeks within their diet.	Other: Unfermented meat alternative; Participants incorporate an unfermented product into their habitual diet for three weeks. The product replaces the main protein source of the meal(s). Participants will receive dietary guidance on how to follow the intervention diet, as well as potential supplement recommendations provided by the authorized nutritionist.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
P-hs-CRP (mg/l)	Weeks 3, 6, 9, and 12
IL-22	Weeks 3, 6, 9, and 12
LBP (μg/ml)	Weeks 3, 6, 9, and 12

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in the composition gut microbiota	Composition of gut microbiota will be analysed from faecal samples	Weeks 3, 6, and 12
Glucose metabolism	fP-Gluk and B-HbA1C (mmol/l)	Weeks 3, 6, 9, and 12
Lipid metabolism	fP-Kol, fP-Kol-HDL, fP-Kol-LDL, fP-Trigly, and fP-FFA (mmol/l)	Weeks 3, 6, 9, and 12
Tryptophan metabolism	Tryptophan metabolites will be analysed with non-targeted metabolomics.	Weeks 3, 6, 9, and 12
Short-chain fatty acids assessed from plasma samples		Weeks 3, 6, 9, and 12
fP-Insu (mU/l)		Weeks 3, 6, 9, and 12
Self-reported overall health (Short Form-36 Health Survey, SF-36)	Different sections are rated from 0 to 100 points, where higher scores mean better perceived health.	Weeks 3, 6, 9, and 12
Self-reported mental health (General Health Questionnaire-12, GHQ-12)	The questionnaire is rated from 0 to 12 points, where higher score means greater psychological distress.	Weeks 3, 6, 9, and 12
Self-reported gastrointestinal symptoms (Gastrointestinal Symptoms Rating Scale, GSRS)	Different symptoms in the questionnaire are rated from 0 to 7, where higher score means greater symptoms.	Weeks 3, 6, 9, and 12

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Opinions about the study products	Unvalidated questionnaire	Weeks 6 and 12
Attitudes and values	Unvalidated questionnaires	Weeks 3 and 12

Collaborators and Investigators

• Sponsor: University of Eastern Finland
• Collaborators: University of Turku; KU Leuven; Umeå University; ETH Zurich; Flemish institute of biotechnology (VIB)
• Investigators: Principal Investigator: Marjukka Kolehmainen, University of Eastern Finland

Study record dates

Study Major Dates

• Study Start (Actual): January 14, 2025
• Primary Completion (Actual): December 12, 2025
• Study Completion (Actual): December 12, 2025

Study Registration Dates

• First Submitted: December 16, 2024
• First Submitted That Met QC Criteria: December 16, 2024
• First Posted (Actual): December 20, 2024

Study Record Updates

• Last Update Posted (Actual): May 12, 2026
• Last Update Submitted That Met QC Criteria: May 11, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Gastrointestinal Microbiome; Inflammation Mediators; Fermentation; Tryptophan; Cardiometabolic Health; Plant Proteins, Dietary
• Additional Relevant MeSH Terms: Metabolic Diseases; Glucose Metabolism Disorders; Insulin Resistance; Hyperinsulinism; Nutritional and Metabolic Diseases; Metabolic Syndrome
• Other Study ID Numbers: 159/2024 HealthFerm

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No