Untargeted\nMetabolomics and Quantitative Analysis\nof Tryptophan Metabolites in Myalgic Encephalomyelitis Patients and\nHealthy Volunteers: A Comparative Study Using High-Resolution Mass\nSpectrometry

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)\nis\na chronic, complex illness characterized by severe and often disabling\nphysical and mental fatigue. So far, scientists have not been able\nto fully pinpoint the biological cause of the illness and yet it affects\nmillions of people worldwide. To gain a better understanding of ME/CFS,\nwe compared the metabolic networks in the plasma of 38 ME/CFS patients\nto those of 24 healthy control participants. This involved an untargeted\nmetabolomics approach in addition to the measurement of targeted substances\nincluding tryptophan and its metabolites, as well as tyrosine, phenylalanine,\nB vitamins, and hypoxanthine using liquid chromatography coupled to\nmass spectrometry. We observed significant alterations in several\nmetabolic pathways, including the vitamin B3, arginine-proline, and\naspartate-asparagine pathways, in the untargeted analysis. The targeted\nanalysis revealed changes in the levels of 3-hydroxyanthranilic acid,\n3-hydroxykynurenine, hypoxanthine, and phenylalanine in ME/CFS patients\ncompared to the control group. These findings suggest potential alterations\nin immune system response and oxidative stress in ME/CFS patients.