Metabolic profiling provides a powerful diagnostic tool complementary to genomics and proteomics. The pain, discomfort and probable iatrogenic injury associated with invasive or minimally invasive diagnostic methods, render them unsuitable in terms of patient compliance and participation. Metabolic profiling of biomatrices like urine, breath, saliva, sweat and feces, which can be collected in a painless manner, could be used for noninvasive diagnosis. This review article covers the noninvasive metabolic profiling studies that have exhibited diagnostic potential for diseases and disorders. Their potential applications are evident in different forms of cancer, metabolic disorders, infectious diseases, neurodegenerative disorders, rheumatic diseases and pulmonary diseases. Large scale clinical validation of such diagnostic methods is necessary in future.
Lay abstract: Metabolic profiling involves determination of changes in metabolite levels caused by diseases and can help in their diagnosis. The pain, discomfort and chance of injury associated with painful diagnostic methods, make them unsuitable in terms of patient compliance. Metabolic profiling of body fluids like urine, breath, saliva, sweat and feces, which can be collected in a painless manner, could be used for painless diagnosis. This review article is about such studies, which have exhibited painless diagnostic potential for diseases and disorders. Their applications are evident in cancer, metabolic disorders, infections, neurodegenerative disorders, rheumatic diseases and lung diseases.