Using Urine to Diagnose Disease

Your body gets rid of over a thousand different small metabolic waste molecules, called metabolites, by excreting them in the urine. In certain diseases one or more of these metabolites may be elevated in urine. Scientists now believe that through “metabolomics” – the study of metabolites – it may be possible to diagnose certain diseases even before symptoms appear in the patient.

The concept is simple; once you know the normal range of excretion of metabolites in urine, a change in the excretion of one or more metabolites might signal the presence of a specific disease. For example, scientists at the University of Michigan measured 1,126 metabolites in urine and found that one of them in particular, called sarcosine, showed promise as a marker for metastatic prostate cancer. The findings were reported in Nature this month.

Unlike blood, urine is easily collected in large quantities by non-invasive techniques. (Put more bluntly, you just pee into a cup!) As the field of metabolomics comes of age, perhaps some day it will be possible to screen for dozens of diseases at once.