Metafollow : one-year longitudinal follow-up to assess metabolites variations in healthy subjects

In healthcare, almost all metabolomics’ studies focus on pathologies by studying inter-individual variation of metabolites. But if we want to apply metabolomics to personalized medicine, we must first understand normal intra-individual variations of metabolites before preventively detect a pathological deviation. Our knowledge of the intra-individual « normal » variations of the metabolome is currently very poor and to expand our expertise, we have first to explore healthy people’s metabolome over a certain period.
For this purpose, we selected 30 healthy volunteers that we followed for one year. According to gold standards of Clinical Chemistry, blood, urine and saliva samples were first collected each week for ten weeks and then each month for ten months. This work first focused on the blood NMR analysis. For the ten weeks’ period, results showed that metabolites could be classified according to their variation, from the less to the most variable ones. The same approach has been applied to the monthly samples and have also highlighted a classification in the metabolites’ variabilities very similar to the weekly ones. Metabolites were also linked to their metabolic pathways to identify the most variable networks.
The results obtained in this preliminary work make it possible to stratify blood metabolites according to their short and long-term variations. The subsequent urine and saliva analyses will complete our data and are expected to give a more complete overview of the normal human metabolome’s variation, which is very important for the application of metabolomics in the context of personalized medicine.