September 5, 2013
Metabolite-Rich Pee May Offer Doctors New Diagnostic Tool
Lee Rannals for redOrbit.com - Your Universe Online
Pee can do more than hint at whether or not you ate asparagus, instead it is giving doctors another diagnostic tool.Researchers at the University of Alberta, publishing a paper in the journal PLoS ONE, said that they found that urine contains more than 3,000 chemicals or "metabolites" that 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," David Wishart, the senior scientist on the project, said in a statement.
Wishart and colleagues used analytical chemistry techniques, including nuclear magnetic resonance spectroscopy, gas chromatography, 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 look through more than 100 years of published scientific literature about urine.
The chemical composition of urine is of particular interest to scientists because it reveals key information about a person's health, what they may have eaten, what they are drinking, what drugs they are taking, and what pollutants they may have been exposed to in their environment.
"Most medical textbooks only list 50 to 100 chemicals in urine, and most common clinical urine tests only measure six to seven compounds," said Wishart. "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."
He said the 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. He said their work is leading to new urine-based diagnostic tests for colon cancer, prostate cancer, celiac disease, ulcerative colitis, pneumonia and organ transplant rejection.
"This is certainly not the final word on the chemical composition of urine," Wishart said. "As new techniques are developed and as more sensitive instruments are produced, I am sure that hundreds more urinary compounds will be identified. In fact, new compounds are being added to the UMDB almost every day."
Last week, scientists from Kaiser Permanente and the National Institute on Aging said that a new urine test could help identify individuals with type 2 diabetes who are at risk of cognitive decline. One company is even seeking FDA approval for an iPhone app that analyzes a urine strip and looks for potential health problems.