Metabolomics

Metabolomics is the quantitative analysis of a large number of low-molecular-weight metabolites that are the intermediate or final products of all the metabolic pathways in a living organism. ^[1] It is the study of metabolite profiles within biological samples, and any metabolic profile detectable in a human biological fluid arises from the interaction between gene expression and the environment. ^{[2] [1]}

Metabolomic analysis can be performed as either global (untargeted) or targeted profiling, drawing on a range of analytical techniques applied to biological samples. ^[2] Liquid chromatography-mass spectrometry has revolutionized untargeted metabolomics analyses by mining metabolomes more deeply, though challenges remain such as poor compound identification that leaves many unidentified peaks. ^[3] Metabolomics studies commonly use nuclear magnetic resonance (NMR) and mass spectrometry (MS) approaches to profile metabolites in samples such as plasma, serum, and urine. ^[4]

Metabolomics-based predictors are one of six recognized types of biological age predictors, alongside epigenetic clocks, telomere length, transcriptomic predictors, proteomic predictors, and composite biomarker predictors. ^[5] Metabolomics involves comprehensive profiling of small molecules within the body and provides the ultimate genome-environment interaction readout, making it a promising basis for metabolomic aging clocks that characterize biological aging. ^[6] Aging clocks based on omics data and machine learning provide a framework for interpreting molecular-level biological aging, because individuals of the same chronological age often exhibit divergent biological aging states. ^[6]

Metabolomics has found wide application in biomarker discovery in medicine, using both global and targeted analysis. ^[2] As an evolving omics technology, metabolomics enables identification of a disease's unique metabolic signature and is a promising tool for early diagnosis, prognosis, and identification of pre-disease states, illustrated in diabetic kidney disease. ^[7] In oncology, metabolomic profiling can track changes in tumor metabolism and gauge treatment response over time, though technical challenges such as database management and cost persist. ^[8]