Mathematical analysis of ~(13)CO_2-expiration curves from human breath tests using 1-~(13)C-amino acids as oral substrate

摘要

A [~(13)CO_2]-breath test examines the expiration of [~(13)CO_2] as function of time after oral intake of a [~(13)C]-labelled test substrate (single dose). In clinical settings, breath test studies are often used as a simple and non-invasive tool to diagnose the activity of metabolic functions. From a nutritional point of view, breath test studies can also be used to trace the catabolic fate of dietary nutrients. The focus of this paper was a mathematical analysis of [~(13)CO_2]-expiration curves. Human breath test results for [~(13)C]-labelled amino acids (leucine, methionine, lysine) under different dietary conditions were used to illustrate this approach. The mathematical parameters were meant to characterise changes in the catabolic fate of dietary amino acids as influenced by the ingestion of a meal.