Metabolomika(daribahasa Inggrismetabolomics) merupakan satu disiplin kajian dalambiologi molekularyang memusatkan perhatian pada keseluruhan produk prosesenzimatikyang terjadi di dalamsel.[1]Proses enzimatik dalam sel merupakan prosesbiokimiawiyang saling berkaitan dan menghasilkankarbohidrat,asam lemak,alkohol,protein, dan berbagai senyawametabolit sekunderlainnya, yang semuanya disebut sebagaimetabolom, termasuk di dalamnya senyawa perantara reaksi enzimatiknya.[1]Metabolomika sulit dipelajari mengingat banyaknya jumlah dan jenis senyawa metabolit yang dapat ada walau hanya di dalam 1 reaksi metabolisme sederhana.[1]Nuclear magnetic resonance(NMR) merupakan salah satu alat yang awalnya digunakan untuk menganalisa suatu sampel dengan menggunakan C13-glukosa.[1]Akan tetapi, penggunaan metode ini masih memiliki banyak keterbatasan, terutama dari sensitivitas dan jumlah senyawa yang dapat diidentifikasi dalam suatu sampel.[1]Berdasarkan keterbatasan ini, dikembangkan metode lain yang memiliki sensitivitas yang tinggi dan dapat mendeteksi berbagai jenis senyawa (protein), yaituspektrometri massa.[1]Metode ini menggunakan resolusi massa yang sangat tinggi yang mampu mendeteksi massa atom (satuan masaa atom, Dalton).[1]Selain itu, spektrometri massa ini juga mampu membedakan isomer dari suatu senyawa berdasarkan pola fragmentasinya.[1]Data yang didapat kemudian dianalisis dengan menggunakanbioinformatika.[2]Metabolome refers to the complete set of small-molecule metabolites (such as metabolic intermediates, hormones and other signaling molecules, and secondary metabolites) to be found within a biological sample, such as a single organism.[18][19]The word was coined in analogy withtranscriptomicsandproteomics; like the transcriptome and the proteome, the metabolome is dynamic, changing from second to second. Although the metabolome can be defined readily enough, it is not currently possible to analyse the entire range of metabolites by a single analytical method. The first metabolite database(calledMETLIN) for searching m/z values from mass spectrometry data was developed by scientists atThe Scripps Research Institutein 2005.[12]In January 2007, scientists at theUniversity of Albertaand theUniversity of Calgarycompleted the first draft of the human metabolome. They catalogued approximately 2500metabolites, 1200drugsand 3500 food components that can be found in the human body, as reported in the literature.[13]This information, available at the Human Metabolome Database (www.hmdb.ca) and based on analysis of information available in the current scientific literature, is far from complete.[20]In contrast, much more is known about the metabolomes of other organisms. For example, over 50,000 metabolites have been characterized from the plant kingdom, and many thousands of metabolites have been identified and/or characterized from single plants.[21][22]Each type of cell and tissue has a unique metabolic fingerprint that can elucidate organ or tissue-specific information, while the study of biofluids can give more generalized though less specialized information. Commonly used biofluids are urine and plasma, as they can be obtained non-invasively or relatively non-invasively, respectively.[23]The ease of collection facilitates high temporal resolution, and because they are always at dynamic equilibrium with the body, they can describe the host as a whole.[24]Metabolites[edit]Metabolites are the intermediates and products ofmetabolism. Within the context of metabolomics, a metabolite is usually defined as any molecule less than 1 kDa in size.[25]However, there are exceptions to this depending on the sample and detection method. For example, macromolecules such aslipoproteinsandalbuminare reliably detected in NMR-based metabolomics studies of blood plasma.[26]In plant-based metabolomics, it is common to refer to "primary" and "secondary" metabolites. A primary metabolite is directly involved in the normal growth, development, and reproduction. Asecondary metaboliteis not directly involved in those processes, but usually has importantecologicalfunction. Examples includeantibioticsandpigments.[27]By contrast, in human-based metabolomics, it is more common to describe metabolites as being eitherendogenous(produced by the host organism) orexogenous.[28]Metabolites of foreign substances such as drugs are termed xenometabolites.[29]Themetabolomeforms a large network ofmetabolicreactions, where outputs from oneenzymaticchemical reactionare inputs to other chemical reactions. Such systems have been described ashypercycles.[citation needed]Metabonomics[edit]Metabonomics is defined as "the quantitative measurement of the dynamic multiparametric metabolic response of living systems to pathophysiological stimuli or genetic modification". The word origin is from the Greekmeaning change andnomosmeaning a rule set or set of laws.[30]This approach was pioneered by Jeremy Nicholson atImperial College Londonand has been used in toxicology, disease diagnosis and a number of other fields. Historically, the metabonomics approach was one of the first methods to apply the scope of systems biology to studies of metabolism.[31][32][33]There has been some disagreement over the exact differences between 'metabolomics' and 'metabonomics'. The difference between the two terms is not related to choice of analytical platform: although metabonomics is more associated withNMR spectroscopyand metabolomics withmass spectrometry-based techniques, this is simply because of usages amongst different groups that have popularized the different terms. While there is still no absolute agreement, there is a growing consensus that 'metabolomics' places a greater emphasis on metabolic profiling at a cellular or organ level and is primarily concerned with normal endogenous metabolism. 'Metabonomics' extends metabolic profiling to include information about perturbations of metabolism caused by environmental factors (including diet and toxins), disease processes, and the involvement of extragenomic influences, such asgut microflora. This is not a trivial difference; metabolomic studies should, by definition, exclude metabolic contributions from extragenomic sources, because these are external to the system being studied. However, in practice, within the field of human disease research there is still a large degree of overlap in the way both terms are used, and they are often in effect synonymous.[34]