Metabonomics: metabolic processes studied by NMR spectroscopy of biofluids

NMR spectroscopy of biofluids provides a wealth of information on the endogenous metabolic processes in an organism. Details of the various types of biofluid and the types of NMR experiment which are useful are given. The features of biofluid NMR spectra are described and practical details of spectral acquisition are also presented. However, the spectra are very complex and many resonances have not been assigned. Therefore, in order to focus on significant differences between a set of spectra from control organisms and from abnormals (e.g., humans with diseases or animals in toxic situations), recourse is made to pattern recognition or chemometric methods. This is exemplifed using NMR spectra of a number of different biofluids such as urine, blood plasma, and cerebrospinal fluid. This approach is encapsulated in the concept of metabonomics, a subject which can be regarded as complementary to studies of the genome (genomics) and the proteins in an organism (proteomics). Metabonomics is defined as "the quantitative measurement of the multiparametric metabolic response of living systems to pathophysiological stimuli or genetic modification.