In recent years, metabolomics has increasingly become one of the life sciences’ key technologies. At the Max Rubner-Institut a decision was taken in 2010 to introduce this technology across the institute under the leadership of the Department of Safety and Quality of Fruit and Vegetables. The goal for the future is to guarantee state of the art in addressing research questions in the field of the quality and safety of food as well as in health-related nutrition research.
The innovative metabolomic approach adopted here does not concentrate exclusively on specifically determining (targeted analysis) any of the known metabolites (metabolic compounds), as is usual in classic analysis, but on using the analysis to detect as many metabolites as possible, be they known or unknown.
This untargeted approach facilitates a relative quantification of all reproducibly detected metabolites, deriving the relative relationship between a certain metabolite in one sample compared with another sample and/or all samples. This method not only allows scientists to detect a significantly larger number of metabolites but also to recognise the importance of unknown metabolites which are then subsequently identified. Its extensive detection of metabolites on the one hand and its open-ended analysis on the other are the great strengths of metabolomics. It means that previously unknown variations between different samples can now be determined.
The human metabolome
Many factors influence the metabolome of a biological system. The human metabolome is dependent, amongst others, on age, gender, genotype, state of health, nutrition and physical activity. Being the product of a highly complex biochemical network, the human metabolome is very variable.
One major goal of nutrition research is to use the characterisation of the human metabolome to identify new biomarkers and demonstrate their influence on nutrition and other lifestyle factors. Currently, it is not known which lifestyle factors determine the human metabolome and which metabolite profile is consistent with health, better quality of life and performance capacity, and thus also with a reduced risk of disease. By building and conducting the metabolic characterisation of its own cohort – the Karlsruhe Metabolomics for Nutrition (KarMeN) cohort, comprising some 250 healthy individuals – MRI wants to help answer these key questions. If it manages to draw sound conclusions on lifestyle-dependent factors that are relevant to human health, this would be an important step towards preventing diseases associated with nutrition.
The food metabolome
Metabolomic analysis also proves to be an innovative, helpful tool in assessing the quality and safety of food as it can be described much more comprehensively in this way. In the future, it will be easier to understand how different cultivation methods or storage conditions affect food quality so that they can be optimised accordingly. In the area of food security, metabolomics can help to assess the safety of new technologies. In plant cultivation, metabolomics is already on the way to becoming an important tool for the selection of resistances.
MRI’s metabolomics platform
At the Max Rubner-Institut, the focus is set on metabolomics methods based on mass spectrometry. In addition, collaboration with Karlsruhe Institute of Technology (KIT) means scientists also have access to NMR spectroscopy.
To date, an untargeted metabolite profiling method using GCxGC/MS has already been established. Depending on the sample matrix, it has been successfully employed to detect 150-400 metabolites, reliably and reproducibly. With the aid of HPLC-MS/MS, two additional targeted methods are available that allow a further 173 metabolites to be quantified. In the future, a second untargeted HPLC-MS/TOF method will complement the platform.