RecruitingNot Applicable

Effects of Omeprazole Ingestion on Postprandial Amino Acid Concentrations in Response to a Mixed Meal

Canada4 participantsStarted 2025-09-01

Plain-language summary

Omeprazole is a proton pump inhibitor commonly used to reduce stomach acid in the treatment of heartburn, gastroesophageal reflux disease, and gastric ulcers. By blocking the H⁺/K⁺-ATPase pumps in the gastric lining, it raises gastric pH and can alter the normal activation of pepsin, the enzyme responsible for beginning protein breakdown in the stomach. Under normal conditions, dietary proteins are denatured by gastric acid and cleaved by pepsin into smaller peptides. These peptides enter the small intestine, where pancreatic enzymes (trypsin, chymotrypsin) and brush-border peptidases (aminopeptidase, dipeptidase) further hydrolyze them into free amino acids that are absorbed into the bloodstream. Suppressing stomach acidity may allow larger peptides to pass into the intestine, potentially reducing the efficiency of amino acid liberation and absorption. In this randomized, crossover study, adults aged 50-60 years will attend two study visits at least one week apart. In one visit they will take a standard dose of omeprazole before consuming a mixed meal with a fixed protein content; in the other visit they will consume the same meal without medication. Blood samples will be collected before the meal and at multiple time points afterward to measure plasma amino acid concentrations and compare postprandial responses. Older adults experience anabolic resistance, meaning they require higher protein intakes to stimulate muscle protein synthesis effectively. If omeprazole reduces amino acid availability after a meal, individuals taking this medication may need adjusted dietary protein recommendations. Findings from this study will help refine nutrition guidelines for people on proton pump inhibitors and support optimal muscle health and recovery in middle-aged and older adults.

Who can participate

Age range50 Years – 60 Years

SexALL

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Inclusion criteria

✓. Healthy adult female or male participants who are 50 to 60 years of age at screening (inclusive)
✓. Has a BMI between 18.5 to 29.9 kg·m-2 (inclusive) at screening visit
✓. In good general health (no uncontrolled diseases or conditions) as deemed by the investigator and able to consume the study product
✓. Has maintained stable use of medication and supplements stable dietary and lifestyle habits, and stable body weight, for the last 3 months prior to screening and agree to maintain them throughout the study
✓. Agree to avoid strenuous exercise 48 h prior to each study visit
✓. Willing to limit daily alcohol consumption to no more than 3 standard drinks per day throughout the study, and agree to entirely avoid alcohol consumption 48 h prior to each visit (a standard serving is defined here as 4 oz wine, 12 oz beer, 1 oz spirits)
✓. Willing to maintain current use of cannabinoids (if applicable) throughout the study
✓. Willing and able to agree to the requirements and restrictions of this study, be willing to give voluntary consent, be able to understand and read the questionnaires, and carry out all study-related procedures.

Exclusion criteria

What they're measuring

Incremental Area Under the Curve for Total Plasma Amino Acid Concentrations

Timeframe: 0-300 minutes post-meal (blood draws at baseline (0), 30, 60, 90, 120, 180, 240, and 300 minutes)

Trial details

NCT IDNCT07142486

SponsorMcGill University

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2026-03

Contact for this trial

Tyler Churchward-Venne, PhD

514-399-9684 tyler.churchward-venne@mcgill.ca

View on ClinicalTrials.gov More Digestive Health trials