Available versus digestible amino acids - new stable isotope methods

Area of Science:

• Nutritional biochemistry
• Protein metabolism
• Food science

Background:

• Food protein quality depends on indispensable amino acid bioavailability.
• Traditional methods (digestibility) have limitations in accounting for gut losses and processing effects.
• A need exists for in vivo human methods to assess metabolic amino acid availability.

Purpose of the Study:

• To develop and validate a novel in vivo method for determining amino acid metabolic availability.
• To apply this method across different species including humans, pigs, and sows.
• To provide a tool for integrating amino acid requirements with food availability.

Main Methods:

• Utilized the indicator amino acid oxidation (IAAO) concept.
• Developed a stable isotope-based metabolic availability method.
• Applied the method in growing pigs, pregnant sows, and adult humans.

Main Results:

• The developed method accurately assesses amino acid metabolic availability in vivo.
• The method is suitable for rapid and routine analysis in human subjects.
• Demonstrated applicability across different life stages and species.

Conclusions:

• The stable isotope-based metabolic availability method is a significant advancement over traditional digestibility assays.
• This method provides a more accurate assessment of amino acid bioavailability for protein synthesis.
• Enables better integration of dietary amino acid supply with human and animal nutritional requirements.