Understanding tryptophan metabolism in healthy young adults

Tryptophan Metabolism in Healthy Young Adults in Response to Graded Tryptophan Intakes: a Pilot Study

This study is testing how healthy young adults process tryptophan, an important amino acid, to see how it affects their health, especially during immune responses.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 6 (estimated)
• Ages: 18 Years to 45 Years
• Sex: Male
• Sponsor: The Hospital for Sick Children (other)
• Locations: 1 site (Toronto, Ontario)
• Trial ID: NCT06551545 on ClinicalTrials.gov

What this trial studies

This study investigates how tryptophan, an essential amino acid, is metabolized in healthy young adults. It aims to develop a method to measure the breakdown products of tryptophan, particularly during immune activation, which may have implications for preterm infants receiving total parenteral nutrition. By examining the competition between the kynurenine and serotonin pathways, the study seeks to clarify how tryptophan metabolism can affect neurological health. Participants will be monitored for their metabolic responses to controlled tryptophan intake.

Who should consider this trial

Good fit: Ideal candidates for this study are healthy adults aged 18 to 45 who meet specific health criteria.

Not a fit: Patients with chronic diseases or acute illnesses affecting protein metabolism, or those on certain medications, may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved nutritional strategies for preterm infants, reducing the risk of neurotoxic effects from tryptophan breakdown.

How similar studies have performed: While the specific approach of this study is novel, related research on tryptophan metabolism has shown potential for understanding its implications in health.

Eligibility criteria

Inclusion Criteria:

1. Consent provided
2. Aged 18 to 45 years old (inclusive)
3. In good general health as evidenced by medical history, physical health and biochemistry
4. Fasting blood glucose, hemoglobin A1c (HbA1c), urea, creatinine and CRP levels within normal ranges for age.

Exclusion Criteria:

1. Presence of chronic disease and/or acute illness known to affect protein/amino acid metabolism (e.g. HIV, diabetes, cancer, liver or kidney disease, neurological conditions including depression and anxiety, hypo- / hyperthyroidism, inflammatory conditions,, anemia, acute cold or flu)
2. Taking medications known to affect protein/AA metabolism (e.g. steroids, anti-inflammatory medications, acetaminophen, selective serotonin reuptake inhibitors (SSRI))
3. Inability to tolerate the diet (i.e. allergy)
4. Significant weight loss during the past month or consumption of weight reducing diets.
5. Significant caffeine consumption (\>2 cups per day)
6. Significant consumption of alcohol (\>1 drink per day i.e. 1 beer or ½ glass of wine).
7. Unwilling to have blood drawn from a venous access or using a ventilated hood indirect calorimeter for the purposes of the study.

Where this trial is running

Toronto, Ontario

• The Hospital for Sick Children — Toronto, Ontario, Canada (RECRUITING)

Study contacts

• Principal investigator: Glenda Courtney-Martin, PhD, RD — The Hospital for Sick Children
• Study coordinator: Nisha Pai, MSc, RD

Conditions: Healthy, adults, healthy, tryptophan, tryptophan breakdown, indicator amino acid oxidation, stable isotope