Metabolomics has the potential to be valuable in a clinical setting where it could be used for early diagnosis of a disease and as a predictor of treatment response and survival. Also, the metabolic status of an individual could be monitored during drug treatment and used to indicate possible toxic effects. Most of the medical treatments today are designed for the average patient using the “one-size-fits-all” approach. Unfortunately, this type of treatment is seen to be very successful for some patients but not for others. In the future, medicine is to be practiced according to algorithms that will take into consideration the patient's characteristics, e.g. their genome, microbiomes, metabolomes, the environment they are exposed to and their lifestyle to make diagnostic and therapeutic strategies precisely tailored to individual patients. This is what we call ‘precision medicine’.