The Effect of a Plant-based, Protein-dense Sauce on Essential Amino Acid Concentrations and Gut Fullness in Older Adults (ProSauce)

Testing the Effect of a Plant-based, Protein-dense Sauce (ProSauce) on Metabolic Availability of Essential Amino Acids and Gut Fullness and Satiety in Older Adults

The goal of this clinical trial is to determine whether meals fortified with plant-based high protein sauce (ProSauce) provide better metabolic availability of essential amino acids compared to meals with standard lower-protein sauce without resulting in excessive gut fullness and satiety. The main questions it aims to answer are:

Does meals with high-protein sauce deliver better metabolic availability of amino acid profile? Does this high-protein sauce also not lead to excessive appetite suppression due to its liquid form? Researchers will compare high protein sauce to a commercially available standard low protein sauce.

Participants will consume two meals, either protein-fortified or standard low-protein sauce, in a randomised order with at least a one-week washout period between each meal. The investigators will collect venous blood samples over a 6-hour postprandial period to measure plasma essential (and non-essential) amino acid and insulin concentrations. The investigators will also measure appetite-related hormones from venous plasma and assess subjective appetite using a visual analogue scale, taken in parallel with the blood sample time points.

Study Overview

• Status: Recruiting
• Conditions: Malnutrition Elderly; Protein Malnutrition
• Intervention / Treatment: Dietary supplement: ProSauce; Dietary supplement: low-protein sauce

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Zhuoxiu Jin, Dr; Phone Number: +447529283410; Email: z.jin3@exeter.ac.uk
• Study Contact Backup: Name: Joanna Bowtell, Prof

Study Locations

• United Kingdom
  • Devon
    • Exeter, Devon, United Kingdom, EX44DZ
      • Recruiting
      • University of Exeter
      • Contact: Zhuoxiu Jin; Phone Number: 07529283410; Email: z.jin@lboro.ac.uk

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Aged 60 and over
• Living independently in the community
• Capacity to provide informed consent
• Non-smoking (vaping is considered smoking)
• No known medical conditions that might influence the study outcomes, e.g., heart disease, diabetes mellitus, obesity, disthyroidism and other endocrinopathies and renal failure
• Not taking any medications that might influence the study outcomes e.g., taking anabolic steroids or corticosteroids long term
• No clinically diagnosed eating disorders
• No severe dislike or allergy to any of the study food
• No hospitalisations in the last 6 months
• Not dieting and weight stable for 3 months before the study (< 3 kg change in weight)

Exclusion Criteria:

• Age < 60y
• Smoking
• Food allergies
• Cognitive and mobility issues
• Hospitalisation in the last 6 months
• Known medical conditions that might influence the study outcomes
• Taking medications that influence the study outcomes

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: ProSauce	Dietary supplement: ProSauce; 10g additional protein from ProSauce
Placebo Comparator: standard sauce	Dietary supplement: low-protein sauce; Commercially available standard low-protein sauce

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Concentrations of essential amino acids	Baseline and postprandial plasma amino acid concentrations will be measured to provides valuable insights into protein digestion and absorption.	Essential amino acid concentrations at time points of baseline, immediately after breakfast (t =0 minute) and t = 20, 40, 60, 90, 120, 180, 240, 300, 360 minutes.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Concentrations of appetite-related gut hormones	Plasma appetite-related hormones i.e., acylated ghrelin, PYY, GLP-1, CCK, will be measured at certain time points via cannulation.	Appetite-related gut hormones will be measured at time points of baseline, immediately after breakfast (t =0 minute) and t = 20, 40, 60, 90, 120, 150, 180, 210, 240 minutes.

Collaborators and Investigators

• Sponsor: University of Exeter
• Investigators: Principal Investigator: Joanna Bowtell, Prof, University of Exeter

Study record dates

Study Major Dates

• Study Start (Actual): July 10, 2025
• Primary Completion (Estimated): October 30, 2025
• Study Completion (Estimated): April 30, 2026

Study Registration Dates

• First Submitted: April 23, 2025
• First Submitted That Met QC Criteria: May 1, 2025
• First Posted (Actual): May 11, 2025

Study Record Updates

• Last Update Posted (Estimated): September 23, 2025
• Last Update Submitted That Met QC Criteria: September 17, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: older adults; appetite regulation; plant-based protein sauce; amino acid metabolic availability
• Additional Relevant MeSH Terms: Severe Acute Malnutrition; Nutrition Disorders; Malnutrition; Nutritional and Metabolic Diseases; Kwashiorkor
• Other Study ID Numbers: ProSauce Uo

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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