Unlocking the urinary metabolome

Written by Lisa Parks, Future Science Group

Multi-platform metabolomic analysis combined with computer-aided literature mining uncovers metabolites behind chemically complex biofluid.

A group of researchers in Canada have recently discovered more than 3000 metabolites in the chemically complex biofluid, urine. Typically, this substrate contains metabolic breakdown products from food, drinks, drugs, environmental contaminants, endogenous waste metabolites and bacterial by-products that are often poorly characterized and poorly understood. The scientists attempted to improve the understanding of this complex biofluid by carrying out a comprehensive study of the urine metabolome.

The study involved both computer-aided literature mining and experimental validation. The latter made use of multiple metabolomics platforms and technologies including NMR, GC–MS, direct flow injection MS, ICP–MS and HPLC for the analysis of multiple human urine samples, identifying 445 and quantifying 378 unique metabolites. The experiments identified many previously unknown metabolites and allowed a comparison between the different platforms and technologies.

The literature review was able to discover another 2206 urinary components and acted as a guide for subsequent experiments. The resulting Urine Metabolome Database contains 2651 metabolite species and their structures (totalling 3079) and is freely available online. The database lists the metabolites, their concentration values and also links them to diseases and clinical data.

Source: Bouatra S, Aziat F, Mandal R et al. The Human Urine Metabolome. PLoS ONE 8(9), e73076 doi:10.1371/journal.pone.0073076  (2013) (Epub ahead of print).