Researchers at the University of Alberta announced today that they have determined the chemical composition of human urine. The study, which took more than seven years and involved a team of nearly 20 researchers, has revealed that more than 3,000 chemicals or "metabolites" can be detected in urine. The results are expected to have significant implications for medical, nutritional, drug and environmental testing.
"Urine is an incredibly complex biofluid. We had no idea there could be so many different compounds going into our toilets," noted David Wishart, the senior scientist on the project.
Wishart's research team used state-of-the-art analytical chemistry techniques including nuclear magnetic resonance spectroscopy, gas chromatography, mass spectrometry and liquid chromatography to systematically identify and quantify hundreds of compounds from a wide range of human urine samples.
To help supplement their experimental results, they also used computer-based data mining techniques to scour more than 100 years of published scientific literature about human urine. This chemical inventory-which includes chemical names, synonyms, descriptions, structures, concentrations and disease associations for thousands of urinary metabolites-is housed in a freely available database called the Urine Metabolome Database, or UMDB. The UMDB is a worldwide reference resource to facilitate clinical, drug and environmental urinalysis. The UMDB is maintained by The Metabolomics Innovation Centre, Canada's national metabolomics core facility.
The chemical composition of urine is of particular interest to physicians, nutritionists and environmental scientists because it reveals key information not only about a person's health, but also about what they have eaten, what they are drinking, what drugs they are taking and what pollutants they may have been exposed to in their environment. Analysis of urine for medical purposes dates back more than 3,000 years. In fact, up until the late 1800s, urine analysis using colour, taste and smell (called uroscopy) was one of the primary methods early physicians used to diagnose disease. Even today, millions of chemically based urine tests are performed every day to identify newborn metabolic disorders, diagnose diabetes, monitor kidney function, confirm bladder infections and detect illicit drug use.