Researchers have determined the chemical composition of human urine and identified more than 3,000 metabolites in the "incredibly complex" bio-fluid.
The results are expected to have significant implications for medical, nutritional, drug and environmental testing. The study at the University of Alberta, 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.
"Urine is an incredibly complex bio-fluid. We had no idea there could be so many different compounds going into our toilets," said David Wishart, the senior scientist on the project.
Wishart's research 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.
They also used computer-based data mining techniques to scour more than 100 years of published scientific literature about human urine.
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.
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, researchers said.
"Expanding the list of known chemicals in urine by a factor of 30 and improving the technology so that we can detect hundreds of urine chemicals at a time could be a real game-changer for medical testing," Wishart said.
Wishart said this study is particularly significant because it will allow a whole new generation of fast, cheap and painless medical tests to be performed using urine instead of blood or tissue biopsies.