Randomized Crossover Trial of Protein Source and Leucine Supplementation on Metabolic and Immune Signaling Pathways

What this Trial Is About

Researchers are studying how different types of protein, specifically animal-based and plant-based proteins, affect metabolism and the immune system in healthy adults. The trial focuses on the role of leucine, an amino acid that influences the mTOR pathway, which regulates cell growth and may be linked to heart-related diseases like atherosclerosis. The study aims to understand whether adding leucine to plant-based protein can mimic the effects of animal protein on the body. Participants will take part in a randomized, controlled, crossover trial where they consume three different smoothies: one with animal-based protein, one with plant-based protein, and one with plant-based protein plus added leucine. Each smoothie provides 50% of calories from protein and is prepared under controlled conditions following Halal and Kosher guidelines. Participants complete three visits, each involving fasting, smoothie consumption, and blood sample collection before and 1 and 3 hours after drinking the smoothie, with at least 3 days between visits. During the study visits, researchers will collect blood samples to measure amino acid levels, especially leucine, and assess the activity of metabolic and immune pathways including mTORC1 signaling and inflammatory markers like IL-6 and TNF-alpha. The study will analyze changes in these markers to understand how protein source and leucine supplementation affect nutrient sensing and immune responses. Participants are healthy adults aged 18 to 65 years, and the total participation includes three clinic visits with fasting and blood draws at each visit.

How Animal and Plant Protein Shakes Change the Body's Nutrient and Health Responses