Validation of the Dual-isotope Method for Measuring Ileal Protein Digestibility

The dual isotope method has been recently developed and used to evaluate indispensable amino acid (IAA) digestibility of various protein food such as legumes, eggs and chicken meat in healthy adults and children. The dual isotope method is an indirect method based on the measurement in plasma of absorbed IAA from a deuterium (2H) intrinsically labeled test protein compared against the same IAA of a carbon 13 (13C) intrinsically labeled standard protein of known digestibility or crystalline amino acids (AA) of theoretical 100% digestibility. However, digestibility data estimated with the dual isotope method have not been directly compared with ileal IAA digestibility directly determined through ileal digesta sampling. The goal of this study is to assess the IAA digestibility of intrinsically 2H-hen's egg in healthy volunteers using both indirect and direct methods.