London:Scientists have developed a new tool to determine the inherent biological differences between individuals -- paving the way for personalised medicine tailored to the specific profile of individual patients. Johan Auwerx of Switzerland's École polytechnique fédérale de Lausanne (EPFL) and Ruedi Aebersold of ETH Zurich, the Swiss Federal Institute of Technology, set out to overcome one of the biggest obstacles in successfully treating metabolic disorders such as diabetes, obesity and fatty liver, which depends on the variation in the way patients respond to medication. Working with mouse models, the researchers successfully connected the variation between individuals' genomes to the variation between their proteomes -- their full set of proteins. In this way, they took a giant leap in profiling the biology of a particular individual. "There is a black box between a patient's genome and their disease," said Auwerx, whose lab handled the genome side of the study published recently in the journal Science. "What we have done here is find a way to fill the black box by obtaining information on the patient's proteome," he added. The study enabled the researchers to better understand the role several proteins play when it comes to metabolising fat and producing energy from it. "Like the mouse strains in this study, each patient with a disease is genetically different," said Aebersold. "The approach we used in the mouse cohort can now be applied one-for-one in research on human diseases, and particularly for personalised medicine," he added. The researchers now aim to be able to customise medical intervention for human patients based on their individual biological makeup.