Metabolomic Biomarkers in the Diagnosis of Non-Alcoholic Fatty Liver Disease

Background: Nonalcoholic fatty liver disease (NAFLD) is the most abundant chronic liver disorder, because racial and ethnic differences may influence prevalence and severity of NAFLD. Objectives: This metabolomic study was conducted to identify the metabolic biomarkers and determine the mechanism of progress of NAFLD in Iranian patients. Methods: Serum samples were collected from 75 participants (37 healthy controls and 38 patients with NAFLD) after an overnight fast. The metabolome of all samples were determined by nuclear magnetic resonance (NMR) and were compared by multivariate statistical analysis. Results: Totally, 19 metabolomic biomarkers were identified by NMR. Compared to healthy controls, NAFLD patients had increased serum concentrations of glycochenodeoxycholic acid, taurocholic acid, glycocholic acid, deoxycholic acid, valine, isoleucine, succinic acid, isocitric acid, 2-ketoglutaric acid, trimethylamine, proline, hydroxyproline and tyrosine, while the concentrations of butyric acid, propionic acid, isovaleric acid, glutamine, glycine, and serine decreased. Conclusions: A robust set of biomarkers for diagnosis of NAFLD was established. Serum metabolomics biomarkers revealed changes in some amino acids and their derivatives, bile acids, short chain fatty acids, and tricarboxylic acid cycle intermediates in subjects with NAFLD compared to healthy controls. These markers could be used as indicators regarding the efficacy of therapeutic interventions.