Unveiling the Metabolic Fingerprint of Occupational Exposure in Ceramic Manufactory Workers

In this study, for the first time urinary NMR-based metabolomics was applied to investigate the physiological alterations associated with occupational exposure in ceramic manufacturing workers. Multivariate analysis revealed a distinctive metabolic signature with exposure, characterized by a depletion of both aliphatic and aromatic amino acids and a concomitant accumulation of branched-chain amino acid catabolites. Alterations in tricarboxylic acid (TCA) cycle intermediates, including citrate and succinate, suggest an involvement of mitochondrial energy metabolism, reflecting adaptive responses to oxidative stress and increased protein turnover. Notably, glycine levels were found increased, consistent with its central role in antioxidant defense and xenobiotic detoxification. Furthermore, changes in urinary host-microbiome co-metabolites, such as 4-hydroxyphenylacetate and phenylacetylglycine, indicate the potential modulation of gut microbial activity in response to occupational exposure. While limited by the small cohort, this study demonstrates the feasibility of NMR-based urinary metabolomics for the non-invasive biomonitoring of workers and suggests its potential as a useful tool for detecting subtle metabolic perturbations associated with complex occupational exposures.