The Metafollow project : One-year longitudinal follow-up to assess intra- and inter-individual variations in healthy subjects

In healthcare, most metabolomics’ studies focus on pathologies by studying inter-individual and/or inter-group variations of metabolites concentrations. However, patients care paradigm is currently changing towards a more personalized approach. Thus, to integrate metabolomics into personalized medicine, understanding normal intra-individual metabolite variations is crucial to identify deviations that may indicate early pathological changes. Currently, our knowledge of these “normal” variations remains limited. To bridge this gap, it’s essential to first study the metabolome of healthy individuals over a defined period.
For this purpose, we conducted a one-year longitudinal study involving 30 healthy volunteers. Blood, urine, and saliva samples were collected weekly for the first ten weeks, followed by monthly collections for ten months, according to the recommendations of the EuBIVAS (EFLM Working Group on Biological Variation). The analysis was first focused on blood samples and as metabolites quantification is absolutely required here, NMR appeared to be the most useful analytical tool. Over the ten-week period, metabolites were classified based on their variability, ranging from the least to the most fluctuating. A similar classification pattern emerged from the monthly samples, confirming the consistency of metabolite variability over time. Additionally, we applied an innovative approach, Metabolomic Informative Content (MIC), to stratify individuals based on the variation in their metabolome.
Our preliminary results enable the stratification of blood metabolites according to their short- and long-term variability. Ongoing urine and saliva analyses will further refine our understanding of normal metabolome variations, providing a more comprehensive foundation for the future application of metabolomics in personalized medicine.