According to our model of genetic information being used by the cell, the DNA is transcribed to RNA, and that RNA is translated into protein. The protein has a function in the cell, and some of the cellular functions involve the protein acting as an enzyme to facilitate the reaction of cellular chemicals called metabolites. Ultimately then, the expression of the DNA will result in many cases as unique metabolites in the cell. In part, the study of metabolomics examines the unique interaction of genotype and phenotype through a characterization of the small molecule metabolites of the cell.  In its simplest form, if the genome represents the blueprint of life, the metabolome represents the ingredients of life.

Researchers at the University of Alberta, in Edmonton, Canada, have announced the completion of the first draft of the human metabolome, the chemical equivalent of the human genome. There is a great potential that the Human Metabolome Project (HMP) will have an immediate impact on medicine and medical practices. 

Additional extensive information is available on the Human Metabolome Project website.