Abstract :
[en] Introduction: Metabolomics is a well-established field whose clinical applications and potential for personalized medicine remain highly promising. Faecal metabolomics is a valuable approach for biomarker discovery, notably in hypertension and colorectal cancer. However, stool samples collected at patients’ homes introduce significant logistical and pre-analytical challenges, especially regarding metabolite stability prior to laboratory processing.
Objective: This study aimed to evaluate the impact of storage conditions and processing delays on faecal metabolite stability.
Method: Stool samples from ten healthy volunteers were stored in two matrices (phosphate-buffered saline alone or supplemented with 0.02% sodium azide, an antimicrobial preservative). Samples stored at 4 °C were centrifuged after 0, 2, 4, 8, and 24 hours, whereas samples stored at room temperature were evaluated at 0 and 2 hours only. NMR spectroscopy enabled the identification and quantification of 28 metabolites. Statistical analyses were performed using paired t-tests and one-way repeated measures ANOVA to assess temporal and storage-related effects.
Results: No significant changes were observed between 0 and 2 h under either temperature condition. In PBS alone, three metabolites showed significant decreases over time: formate (from 2 h), and butyrate and methylamine (from 8 h). In PBS supplemented with sodium azide, five metabolites were significantly affected after 8 h: glutamate, lysine, and tyrosine increased, whereas formate and methylamine decreased. Overall, 22 of the 28 quantified metabolites remained stable across matrices and time points.
Conclusion: These findings underscore the impact of storage matrices on metabolite concentrations and support the development of standardized, clinically applicable protocols for faecal metabolomics.
