Effect of Dairy Protein Yogourt vs Plant-based Yogourt on Body Weight, Body Composition, Bone Health and Gut Microbiota (PROYO)

A New Focus on Protein and the Gut Microbiota to Explain Health Benefits of Dairy Foods

The consumption of an adequate quantity of protein in the diet is essential to maintain a healthy body composition and functioning. It is also well established that all proteins are not equal regarding their ability to promote health benefits. Recently, we have innovated in that matter by showing that under the context of high intake of dietary fat, the dairy protein casein was more effective than a mix of proteins representative of a western diet to prevent body weight gain and insulin resistance. This was explained in part by modifications of the gut microbiota. This finding represents the main conceptual basis of the present research program that is aimed to determine the impact of dairy protein from yogurt compared to a plant-based equivalent on body composition indicators including muscle mass and bone mineral density, in relation to the profile of the gut microbiota, the production of newly discovered protein-derived metabolites, and markers of metabolic health. This program will include a human and an animal component requiring the testing of these variables before and after a standardized intervention. The human component will be a clinical study consisting of a 12-week diet-based weight loss intervention in postmenopausal overweight women being randomly assigned to one of the three following groups: yogurt, plant-based yogurt, or kept on diet without supplements. The animal experimentation will permit to causally determine the implication of the gut microbiota in the protein effects following transfer of the human bacteria to germ free mice and validate the benefits seen in humans. It is anticipated that these two complementary investigative approaches will allow a thorough documentation of the impact of fermented dairy protein on body composition and functioning, a better understanding of the underlying mechanisms, and the identification of new biomarkers to better appreciate related health benefits.

Study Overview

• Status: Recruiting
• Conditions: Gut Microbiota; Bone Health; Body Composition Changes; Bone Metabolism; Metabolic Health; Body Weight Change
• Intervention / Treatment: Dietary supplement: Dairy yogurt; Dietary supplement: Plant based yogurt; Dietary supplement: No yogurt

• Study Type: Interventional
• Enrollment (Estimated): 75
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Julie Marois, M.Sc.; Phone Number: 1-418-656-5258; Email: julie.marois@fsaa.ulaval.ca

Study Locations

• Canada
  • Quebec
    • Québec, Quebec, Canada, G1V 0A6
      • Recruiting
      • INAF, Université Laval
      • Contact: Julie Marois, M.Sc.; Phone Number: 1-418-656-5258; Email: julie.marois@fsaa.ulaval.ca
      • Principal Investigator: André Marette, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Postmenopausal women (absence of menstruation for at least 1 year and FSH > 40 IU/L)
• BMI between 27.0 and 39.9 kg/m²
• Sedentary or moderately active

Exclusion Criteria:

• Body weight change greater than 5 kg in the 3 months preceding the study
• Currently dieting or following specific dietary patterns
• Previous or planned bariatric surgery
• Food allergies or intolerances (particularly dairy proteins and lactose)
• Serious or problematic health conditions (e.g., renal insufficiency, diabetes, Cushing's disease, Paget's disease, parathyroid disorders, inflammatory bowel disease, uncontrolled thyroid disease, etc.)
• Fracture within the past year
• Hormone therapy
• Medications affecting bone metabolism (e.g., osteoporosis treatments, anti-estrogen therapy for breast cancer, epilepsy treatments)
• Antibiotic use within the 6 months preceding the study
• Use of probiotic supplements (capsules)
• More than two alcoholic drinks per day
• Smoking
• Drug abuse

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dairy yogurt	Dietary supplement: Dairy yogurt; Dairy yogurt: two serving daily
Active Comparator: Plant-based yogurt	Dietary supplement: Plant based yogurt; Plant based yogurt: two servings daily
Placebo Comparator: No yogurt	Dietary supplement: No yogurt; No yogurt: zero serving yogurt

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in bone health	Assessment of bone mineral density using Dual X-ray Absorptiometry scan	At baseline and at the end of the intervention (12 weeks)
Change in bone health	Assessment of bone turnover biomarkers (osteocalcin, c-telopeptide, Amino terminal propeptide of type 1 procollagen) (all in ng\mL)	At baseline and at the end of the intrevention (12 weeks)
Change in gut microbiota	Assessment of global variation of the fecal microbiota	At baseline and at the end of the intervention (12 weeks)
Change in gut microbiota function	Assessment of short-chain fatty acid (SCFA) in feces	At baseline and at the end of the intervention (12 weeks)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in body weight		At baseline and at the end of the intervention (12 weeks)
Change in anthropometric measures	Assessment of body mass index (BMI) using weight and height. These two measurements will be combined to calculate BMI in kg/m2	At baseline and at the end of the intervention (12 weeks)
Change in anthropometric measure	Assessment of waist circumference	At baseline and at the end of the intervention (12 weeks)
Change in body composition	Assessment of changes in lean mass, fat mass and visceral fat mass (all in grams) using body composition by Dual X-ray Absorptiometry scan	At baseline and at the end of the intervention (12 weeks)
Change in skeletal muscle health	muscle strength using handgrip strength tool (kg)	At baseline and at the end of the intervention (12 weeks)
Change in skeletal muscle health	Assessment of physical performance using Timed Up and go Test	At baseline and at the end of the intervention (12 weeks)
Change in skeletal muscle health	Assessment of functionnal capicity using 6-minute walk test)	At baseline and at the end of the intervention (12 weeks)
Change in Resting Metabolic Rate (RMR)	Change in RMR using Calorimetry Device	At baseline and at the end of the intervention (12 weeks)
Change in Appetite and Satiety	Assessment of leptin and ghrelin (both with same units of measurement)	At baseline and at the end of the intervention (12 weeks)
Change in Appetite and Satiety	Assessment of appetite and satiety using visual analog scale	At baseline and at the end of the intervention (12 weeks)
Change in Eating behaviors	Assessment of eating behaviors using Food Cravings Questionnaire (FCQ-T)	At baseline and at the end of the intervention (12 weeks)
Change in glycemia	Assessment of fasting glucose concentration	At baseline and at the end of the intervention (12 weeks)
Change in insulinemia	Assessment of fasting insulin concentration	At baseline and at the end of the intervention (12 weeks)
Change in lipid profile	Assessment of triglycerides, LDL-cholesterol and HDL-cholesterol	At baseline and at the end of the intervention (12 weeks)
Change in blood pressure	Assessment of systolic and diastolic blood pressure	At baseline and at the end of the intervention (12 weeks)
Change in chronic inflammation	Assessment of plasma high sensitive C-Reactive Protein (hs-CRP) concentrations	At baseline and at the end of the intervention (12 weeks)

Collaborators and Investigators

• Sponsor: Laval University

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2023
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: May 5, 2026
• First Submitted That Met QC Criteria: May 5, 2026
• First Posted (Actual): May 11, 2026

Study Record Updates

• Last Update Posted (Actual): May 11, 2026
• Last Update Submitted That Met QC Criteria: May 5, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Body Weight; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Body Weight Changes
• Other Study ID Numbers: PROYO 2022-108

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No