Researchers Decipher Chemical Composition of Human Urine

Researchers have determined the chemical composition of human urine, announcing that it has more than 3,000 chemicals, or "metabolites."

Using state-of-the-art analytical chemistry techniques, including nuclear magnetic resonance spectroscopy, gas chromatography and liquid chromatography, the team of nearly 20 researchers from the University of Alberta systematically identified and quantified hundreds of compounds from a wide range of human urine samples.

In addition, the scientists used computer-based data mining techniques to analyze more than 100 years of published scientific literature on urine.

"Urine is an incredibly complex biofluid. We had no idea there could be so many different compounds going into our toilets," David Wishart, the senior scientist on the project, said in a statement.

Urine's chemical composition is especially relevant to physicians, nutritionists and environmental scientists due to what it can reveal about a person's health, including what they have eaten, what they are drinking, what drugs they are taking and any pollutants they might have been exposed to. Currently, chemically-based urine tests are used to identify newborn metabolic disorders, diagnose diabetes, monitor kidney function, confirm bladder infections and detect illicit drug use.

"Most medical textbooks only list 50 to 100 chemicals in urine, and most common clinical urine tests only measure six to seven compounds," Wishart 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."

According to Wishart, the study could pave the way to a new generation of fast, cheap and painless urine-based medical tests, replacing blood samples or tissue biopsies.

Already under development as a result of the study are urine tests that could one day detect colon cancer, prostate cancer, celiac disease, ulcerative colitis, pneumonia and organ transplant rejection, the researchers report.

"While the human genome project certainly continues to capture most of the world's attention," Wishart said, "I believe that these studies on the human metabolome are already having a far more significant and immediate impact on human health."