Metabo-tip: a Metabolomics Platform for Lifestyle Monitoring

Abstract Exposure to bioactive compounds from nutrition, pharmaceuticals, environmental contaminants or other lifestyle habits may affect the human organism. To gain insight into the effects of these influences, as well as the fundamental biochemical mechanisms behind them, molecular profiling seems promising. To address this problem, we developed an assay for the analysis of sweat, collected from finger tips, using mass spectrometry – by far the most comprehensive and sensitive method for such analyses. To evaluate this assay, called metabo-tip, we exposed volunteers to various xenobiotics using standardized protocols and investigated their metabolic response. As early as 15 minutes after the consumption of a cup of coffee, 50g of dark chocolate or a serving of citrus fruits, significant changes in the sweat composition of the finger tips could be observed, providing relevant information in regards to the ingested substances. This included bioactive compounds such as natural flavonoids as well as potential hazardous substances such as pesticides. Furthermore, the identification of metabolites from nicotine after cigarette smoking and metabolites from orally ingested medications such as metamizole indicated the applicability of this assay to observe specific enzymatic processes. Remarkably, we found that the sweat composition fluctuated in a diurnal rhythm, supporting the hypothesis that the composition of sweat can be influenced by endogenous metabolic activities. This was further corroborated by the finding that histamine was significantly increased in the metabo-tip assay in individuals with allergic reactions. Metab-tip may thus enable direct access to individual metabolic profiles and may thus support predictive preventive personalised medicine (PPPM).