Dietary Proteins: Metagenomic and Metabolomics Approaches for Human Biomarkers Identification
Condition: Healthy
Study type: Interventional

Summary: 
      This project aims to create a methodological framework, including the discovery and
      validation of novel biomarker panels to decipher the impact of plant-based protein intake on
      health biomarkers. Moreover, the possibility of predicting biomarkers production will be
      tested by a colonic in vitro fermentation study using study participants' faecal samples.
    

Detailed description: 
      This study consists of a double-blind, randomised, 3-arm parallel trial, consisting of 2-wk
      baseline measurements, 4-wk intervention period (with weekly sample collection), and 2-wk
      after-intervention follow-up, with healthy subjects in each arm consuming different protein
      sources (from plant- or animal-based sources). Subjects that are eligible to take part in
      this study will be blinded and randomly allocated to consume an isolated pea protein (arm 1),
      animal protein (arm 2) or more complex protein pea protein powder (arm 3). The isolated plant
      and animal protein will be used to evaluate the specific effects of the proteins from the
      different sources. The more complex protein pea protein powder will be used as a more complex
      food matrix, containing other food components than protein, to assess how other pea
      components may impact the specific protein effects. Regardless of the differences in their
      structure, all supplement powders will be adjusted to provide the same amount of protein. The
      protein calculation will be done exclusively for each participant, based on their body weight
      (kg). They will consume up to 2 g of protein per body weight per day. Subjects will be asked
      to maintain their usual diet and their food intake will be accompanied during the
      intervention.

      Participants' compliance will be followed by their food diaries and by clinical markers for
      protein intake and will collect blood, faeces and 24 h urine samples. A subset of the
      participants (max. 15 per arm) for visits 2 and 6 will be invited to participate in a
      postprandial challenge. After the fastening blood sample collection, they will receive the
      daily protein portion as breakfast. For those, 9 blood sample time points will be taken,
      being at 0, 15, 30, 60, 90, 120, 150, 180, and 480 min. After the 180 min measurement, they
      will receive a standard meal as lunch (e.g., pasta with tomato sauce).
    

Intervention name(s): Protein supplementation
Intervention type(s): Dietary Supplement
Intervention description(s): Participants will be instructed to dissolve the protein powder in liquids (such as water) or on their food (e.g., yoghurt, oat porridge). A subset of the participants (max. 15 per arm) for visits 2 and 6 will be invited to participate in a postprandial challenge, where they will receive the daily protein portion as breakfast.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Healthy male and female adult subjects (n=87) will be recruited to take part in a double-blinded, randomized, 3-arms parallel trial. Subjects that are eligible to take part in the study will be blinded and randomly allocated to consume an isolated plant protein (arm 1) or isolated animal protein (arm 2) or plant-based source of protein (arm 3). The subjects eligible to take part in this study will consume the proteins for 4 weeks, before the intervention they will have a baseline of two weeks, and after the intervention, they will have more two visits. Faecal and blood samples will be used to answer the main outcome of gut-related metabolites and microbiota profile. Blood and urine samples will be used to measure health status and compliance (protein intake markers). Questionnaires will be used to access gastrointestinal symptoms and bowel movement, physical activity level and dietary intake.
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Basic Science