Metabolomics and Metabonomics

Metabolomics is the study of small compounds, often known as metabolites, in cells, biofluids, tissues, and organisms on a massive scale. The metabolome refers to the collection of tiny molecules and their interactions inside a biological system. Metabolomics is a strong method because, unlike other "omics" metrics, metabolites and their concentrations directly represent the underlying biochemical activity and condition of cells and tissues. As a result, metabolomics is the best representation of the molecular phenotype. The metabolome refers to the entire set of small-molecule (1.5 kDa) metabolites identified in a biological sample, such as a single organism (metabolic intermediates, hormones and other signalling molecules, and secondary metabolites). The term was coined in the same way as transcriptomics and proteomics were coined; the metabolome, like the transcriptome and proteome, is dynamic, changing from second to second. Despite the ease with which the metabolome may be described, it is currently not possible to analyse the whole range of metabolites using a single analytical approach.

Metabonomics is being combined with genomics and proteomics to form a new systems biology that takes into account the complex interrelationships between the genome, proteome, and metabolome. Metabonomics is a subset of metabolomics, defined as the quantitative measurement of multiparametric metabolic responses of living systems to pathophysiological stimuli or genetic modification, with a focus on elucidating differences in population groups due to genetic modification, disease, and environmental (including nutritional) stress. Metabonomics usually encompasses not only intracellular molecules but also external biofluid components.