metabolomics

Metabolomics is the "systematic study of the unique chemical fingerprints that specific cellular processes leave behind" - specifically, the study of their small-molecule metabolite profiles. The metabolome represents the collection of all metabolites in a biological organism, which are the end products of its gene expression.
This approach is increasingly used in toxicology, disease diagnosis and a number of other fields including nutrition. One of the challenges of systems toxicology, and more generally systems biology, is to integrate proteomic, transcriptomic and metabolomic information to give a more complete picture of living organisms.
Metabolomics and metabonomics provide an overview of the metabolic status and global biochemical events associated with a cellular or biological system. They can accurately and comprehensively depict both the steady-state physiological state of a cell or organism and of their dynamic responses to genetic, abiotic and biotic environmental modulation. An increasing focus in metabo(l/n)omics research is now evident in academia, industry and government.

Source: Wikipedia & IHCP, JRC Project Browser

See IHCP's disclaimer on linked sites