What is the Human Exposome? — Chromatography Explores

The debate between nature — the inherited characteristics we are all born with — and nurture — our impact with the environment after birth — has raged for centuries. Great leaps forward in our understanding of how nature affects us have been made ever since Watson and Crick announced the structure of deoxyribose nucleic acid in 1953.

Since then, links between our genetic make-up and disease have been made leading to new branches of medicine dealing with genetics. We can manipulate our genes and just over ten years ago, the entire human genome was sequenced — an amazing achievement. But, that doesn’t mean that nurture was forgotten. Indeed, the limitations of genetics in helping us to predict and cure disease was soon understood and scientists realised that nurture had a massive role to play.

Dr Wild’s idea — the environment is important

The idea and term exposome was coined in 2005 by Dr Christopher Wild in a paper ‘Complementing the Genome with an “Exposome”: The Outstanding Challenge of Environmental Exposure Measurement in Molecular Epidemiology’ published in the journal Cancer Epidemiology, Biomarkers & Prevention. But what exactly is the exposome?

Since Dr Wild first suggested the exposome, the idea has been modified and is now an active area of research. In a paper published in Toxicological Sciences, Gary Miller and Dean Jones suggest the definition:

Exposome: The cumulative measure of environmental influences and associated biological responses throughout the lifespan, including exposures from the environment, diet, behavior, and endogenous processes

The exposome therefore encompasses all our exposures including from diet, our lifestyles — smoking and alcohol — and our behaviours. When combined with our genetic knowledge and advances in medicine, researchers believe that that the exposome will help us to understand and treat disease and illness better than we can at the moment.

Breathe into this tube please

Basically, the exposome is all the chemicals in our bodies that don’t come from our genes — this includes substances that come from cells or other reactions in the body as well as substances from external environments. And scientists suggest that over 70% — and possibly up to 90% — of human disease can be associated with environmental factors.

So how can we monitor the exposome? One method is breathe analysis — a topic discussed by Professor Joachim Pleil at this year’s Pittcon. Modern breath analysis doesn’t just include volatiles — but particles, aerosols and lots of dissolved particles. Dr Pleil explains how both gas and liquid chromatography are used to analyse our breath — giving researchers an insight into our exposome — and also the advances in chromatography that would be useful for exposome researchers. A discussion on how the improvement in column technology affects the analysis of biological molecules is discussed in the article, Faster Analysis of Monoclonal Antibodies Using Silica Monoliths Designed for Bioanalysis.