The Human Metabolome

The human metabolome is best understood by analogy to the human genome, i.e. where the human genome is the set of all genes in a human, the human metabolome is the set of all metabolites in a human. Whereas the science of genomics is based upon a genome, the science of metabolomics is grounded in a metabolome. To continue the genome/metabolome analogy, it should be apparent that any published human genome is a statistical approximation as it is derived from a limited number of individuals, and that, ultimately, any individual has a unique genome. Similarly, the human metabolome is a statistical approximation of the total human metabolic potential. Furthermore, just as the human genome is differentiable from other genomes, for instance, the Xenopus or Caenothus genomes, there is a human metabolome that defines the human biochemical potential that is different from that of Xenopus o r Caenothus. While the vitamins and essential amino acids are the most obvious unique characteristics of the human metabolome they are not, by any means, the only defining features. By its definition, the metabolome is the comprehensive set of all potential metabolites that can be expressed in any human under all conditions, the high-water mark of human biochemical potential. It is likely that most individuals vary in their biochemical potential, expressing only incomplete subsets of the metabolome, depending on their genetic makeup and health state. Indeed, many metabolic diseases and even the efficacy of most drugs are variable, due, at least in part, to individual variances in metabolism and the resulting biochemistry. Fundamentally, the concept of a metabolome is based in set theory. The metabolome is the total set, and all individuals, tissues, and conditions are subsets. What is unique about the metabolome is its ability to directly reflect physiological status when used as part of a metabolomic analysis. This manuscript will explore the implications of the human metabolome and explore ways for their generation and use.