The Impact of Plant-Based Protein-rich Food Products With Varying Degree of Processing on the Human Gut Microbiome Composition and Human Metabolome

Study Overview
=================
Brief Summary
-----------------
It is observed that replacing meat with protein-rich plant-based food products are associated with lower mortality and obesity prevention. Sources of plant proteins typically undergo several processing and refinement procedures to improve the taste and digestibility of plant-based food products. These procedures alter the chemical composition, which can impact the nutritional quality of the processed food. It is not known what is the impact of processed products on human metabolism and intestinal microbiota. Therefore, the impact of a set of plant-based protein-rich food products with varying degree of processing on the composition and function of human gut microbiome and metabolism will be assessed in a clinical intervention

Detailed Description
-----------------
Plant-based diets are known to have beneficial effects on both the environment and human health. Replacing animal protein with plant protein reduces overall mortality risk, and replacing meat with legumes and other sources of plant protein can lower the risk of chronic diseases such as type 2 diabetes and cardiovascular disease. However, the benefits of plant protein products is not evident. In order to make plant protein products more palatable and digestible, plant raw materials may go through several processing and refinement procedures. Typically, during these phases, carbohydrate fractions (e.g. dietary fiber) are removed from the plant material, which results in the loss of micronutrients as well as secondary plant metabolites with potentially health effects (e.g. polyphenolic compounds). Salt and various fats are added to some products, which can reduce the nutritional quality of the product. Subsequently, not all plant-based protein-rich foods are automatically healthy as there may be significant differences in the nutritional quality of the processed products, depending on the food processing utilized. Only little research information is available on the effects of processed plant protein products on human metabolism and intestinal microbiota. Therefore, this cross-over clinical intervention will be conducted with 38 healthy participants to investigate the impact of a set of plant-based protein-rich food products with varying degree of processing on the composition and function of human gut microbiome and metabolism will be assessed in a clinical intervention.

Official Title
-----------------
The Impact of Plant-Based Protein-rich Food Products With Varying Degree of Processing on the Human Gut Microbiome Composition and Human Metabolome

Conditions
-----------------
Metabolism, Gut Microbiota, Inflammation

Intervention / Treatment
-----------------
* Behavioral: Unprocessed
* Behavioral: Mildly processed
* Behavioral: Heavily refined


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Willingness to participate 18-65-years olf BMI 18.5-27 kg/m2 Exclusion Criteria: Chronic disease with continuous medication Antibiotic use in the past 6 months Active smoker Gluten-free or vegan diet Pregnancy, lactation Abnormal thyroid, liver, or kidney function Low hemoglobin

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Crossover trial with two one-week wash-out periods in-between three interventions
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Diet 1<br>Unprocessed or minimally processed plant-based protein-rich food products | Behavioral: Unprocessed<br>* Participants will consume unprocessed or minimally processed commercially available plant-based protein-rich foods as meat replacement in their normal diet for one week.<br>|
| Experimental: Diet 2<br>Mildly processed plant-based protein-rich food products | Behavioral: Mildly processed<br>* Participants will consume mildly processed commercially available plant-based protein-rich foods as meat replacement in their normal diet for one week.<br>|
| Experimental: Diet 3<br>Heavily refined plant-based protein-rich food products | Behavioral: Heavily refined<br>* Participants will consume heavily refined processed commercially available plant-based protein-rich foods as meat replacement in their normal diet for one week.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Metabolomics | The changes in metabolism evoked by the interventions | one week between the start and end of each intervention | 
| Transcriptomics | The changes in endogenous gene expression on RNA level | one week between the start and end of each intervention | 
| Metagenomics | The alterations in the composition of gut microbiota | one week between the start and end of each intervention | 
| Inflammation status by inflammatory cytokines | The changes in inflammatory cytokines | one week between the start and end of each intervention | 
| Inflammation status by high-sensitive CRP | The changes in high-sensitive CRP by clinical biochemistry analysis | one week between the start and end of each intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Glucose homeostasis | Fasting plasma glucose and insulin concentrations by clinical biochemistry analyses | one week between the start and end of each intervention | 
| Lipid homeostasis | Cholesterol and triglyceride concentrations by clinical biochemistry analyses | one week between the start and end of each intervention | 
| Body weight | Body weight in kilograms measured by standard weight scale | five weeks (baseline and at the end of the complete study / after three interventions and 2 wash-outs) |