Postprandial test: A meal containing pea protein labelled with 15N will be eaten by volunteers and dietary nitrogen kinetics will be measured in plasma urea, free amino acids and protein as well as in urinary urea.
Amino acid bioavailability: A meal containing pea protein labelled with 2H will be given in a small portions every 30 minutes together with a dose of 13C-labelled amino acid and bioavailability of pea amino acid will be determined with the dual isotopic tracer method.
Study summary
Plant proteins are usually less digestible than animal proteins, but they may benefit gut health through effects on the microbiome. The long-term impact of diets rich in plant products on protein digestion and metabolism is still unknown, especially in older adults with higher protein needs. This study aims to compare the digestion and use of pea proteins in young and older adults, both vegetarians and omnivores. Volunteers are divided into four groups: young omnivores, young vegetarians, older omnivores, and older vegetarians. They take part in two clinical investigation days. On the first day, nitrogen retention and protein metabolism is measured after consumption of a pea-based meal. On the second day, amino acid digestibility of pea is evaluated. These results will provide valuable data on how plant proteins are digested and metabolized depending on age and diet. They will also help determine whether aging reduces the availability of plant proteins. This knowledge is important to support nutritional strategies for populations with specific protein needs, such as older adults.
Eligibility
Sex
ALL
Min age
18 Years
Max age
75 Years
Healthy volunteers
Accepted
Inclusion Criteria:
* Normal weight or overweight (18 \< BMI \< 30 kg·m-²)
* Male or female
* Aged 18-23 years (young groups) or 65-75 years (older groups)
* Following an omnivorous diet (regular consumption of meat products, with meat intake \> 3 times/week and \> 70% of protein intake from animal sources) or vegetarian diet (exclusion of meat and fish/seafood, with \> 70% of protein intake from plant sources)
* In good general health (WHO = 0)
* Affiliated with a social security system
* Free and informed consent, provided in writing after receiving the information required by the Public Health Code
Exclusion Criteria:
* Adults under legal protection or unable to give informed consent (e.g., under guardianship, trusteeship, or legal protection)
* Any known food allergy
* Positive serology for HBsAg, anti-HBc, HCV, or HIV
* Anemia: hemoglobin level \< 13 g/dL in men and \< 12 g/dL in women
* Pregnant women or those who may be pregnant (based on a positive urine pregnancy test at inclusion)
* Excessive alcohol consumption (\> 2 drinks/day). Harmful alcohol use will be assessed by the investigator at inclusion.
* Hypertension, diabetes, gastrointestinal, liver or kidney diseases, or severe heart disease. These conditions will be assessed by the investigator based on standard clinical evaluation and participants' self-reports at inclusion.
* Hypertension: significant arterial hypertension according to the investigator, or systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg at inclusion.
* Diabetes: type 1 or type 2 diabetes, or fasting blood glucose \> 1.25 g/L.
* Gastrointestinal disease: clinically significant gastrointestinal disorders (bleeding, vomiting, constipation/diarrhea grade \> 1) as judged by the investigator, any inflammatory bowel disease, or acute gastroenteritis in the month prior to the intervention.
* Liver disease: any significant hepatic disorder according to the investigator, or ASAT/ALAT \> 2.5 times the upper normal limit.
* High-level athletes (\> 8 hours of training per week)
* Blood donation within 8 weeks prior to study start
* Absence of free, informed, written consent after receiving the information required by the Public Health Code
* Not affiliated with a social security system
Primary outcome measure(s)
Pea amino acid bioavailability (%) — From the begining of the second investigation day (8:00) to 8 hours after the first meal intake (around 18:00). During the second inverstigation day, the feeding protocol in portions of the meal (pea protein labelled with 2H and dose of 13C-free amino acids) will make it possible to obtain a plateau of isotopic enrichment in 2H and 13C in plasma amino acid. The ratio of 2H isotopic enrichment to 13C isotopic enrichment for each amino acid in the meal and in plasma, corrected by the digestibility of the reference protein (13C-labeled free amino acid mixture with a theoretical digestibility of 100%), makes it possible to determine the bioavailability (also called digestibility) of amino acids from pea protein in the different groups and expressed as % pea amino acids.
Trial sites (1)
Facility
City
Region
Status
Centre de Recherche sur Volontaire, Hopital Avicenne (AP-HP)
Bobigny
France
Recruiting
More Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement trials in France
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
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