The field of metabolomics continues to grow rapidly over the last decade and has 
been proven to be a powerful technology in predicting and explaining complex 
phenotypes in diverse biological systems. Metabolomics complements other omics, 
such as transcriptomics and proteomics and since it is a 'downstream' result of 
gene expression, changes in the metabolome is considered to best reflect the 
activities of the cell at a functional level. Thus far, metabolomics might be 
the sole technology capable of detecting complex, biologically essential 
changes. As one of the omics technology, metabolomics has exciting applications 
in varied fields, including medical science, synthetic biology, medicine, and 
predictive modeling of plant, animal and microbial systems. In addition, 
integrated applications with genomics, transcriptomics, and proteomics provide 
greater understanding of global system biology. In this review, we discuss 
recent applications of metabolomics in microbiology, plant, animal, food, and 
medical science.