Identification of metabolic biomarkers for personalized nutrition.

Now more than ever, we have begun to appreciate the roles of individual physical and genetic variation in health and medicine. A great deal of research attention has recently been devoted toward personalized medicine, in which technologies like medical genetics are used to determine information such as how a patient is likely to respond to a treatment or the optimal dose of a drug. While drug therapy will undoubtedly advance as a result of this new focus, it is critical that we not overlook the importance of personalized nutrition in disease management and health promotion. Indeed, personalized nutrition may be even more critical than personalized medicine given that dietary intake is a fundamental part of everyday life that affects our health. The fields of nutrigenetics and nutrigenomics present uniquely powerful sources of information for implementing personalized nutrition. Nutrigenetics specifies how individual genetic variance impacts response to nutrients such that an individual can avoid negative metabolic consequences by choosing appropriate foods. One classic example is lactose intolerance, in which one lacks the lactase persistence allele and therefore cannot digest lactose [1] . Thus, this person’s health would benefit from avoiding foods containing lactose. On the other hand, nutrigenomics explores how nutrients affect gene expression, so that ingesting certain nutrients according to an individual’s health condition can normalize their diseaserelated gene expression. For example, increased systemic inflammation is linked to an upregulation of inflammatory cytokines (e.g. TNF , IL-1, IL-6), which can in turn be suppressed by some nutrients (e.g. omega-3 fatty acids [2] ). The key element linking these ‘sister’ fields is the concept that nutrients interact with an individual’s genetic profile to impact their health. Thus, as each individual has their own unique genetic profile, this knowledge is essential for developing personalized nutrition. The critical prerequisite for personalized nutrition is the ability to precisely detect and interpret an individual’s metabolic and health status by way of metabolic biomarkers. These