Fecal metabolite profiling as first step towards a fingerprint/biomarker-screening tool for disease assessment

An increasing awareness exists that many intestinal diseases and in particular inflammatory bowel disease (IBD) and colorectal cancer (CRC), are intrinsically linked to alterations in the mammalian-microbial symbiosis (known as dysbiosis). In recent years, metabolic fingerprinting has emerged as an innovative approach in disease surveillance, which may ultimately lead to the elucidation of early biomarkers of pathogenesis, metabolites directly correlated with the dysbiosis determinants. In this context, the use of Fourier Transform Orbitrap mass spectrometry allows a true “omics” fingerprint through the analysis of non-invasive samples (stool, exfoliated colonocytes, etc.) derived from patients (IBD and CRC) as compared to healthy individuals. The statistical interpretation of this data, by means of orthogonal partial least squares-discriminant analysis, enables to characterize potential biomarkers. A common pitfall however with metabolomic approaches is the holistic nature of the analysis, i.e. the assurance that the developed method is capable of detecting a variety of metabolites differing in physico-chemical properties, thereby representing the metabolic content of the studied matrix. Therefore, an important first step to obtain this holistic metabolomic method is the development of a targeted analysis enabling the detection of relevant biological metabolites. In this study, over 130 reference compounds (amino-, bile-, hydroxylic- and, carboxylic acids, amines, carbohydrates, short chain fatty acids, N-nitroso compounds, polyols and sterols), which were reported in previous gastrointestinal metabolomic work, were included. This targeted approach enabled profiling of fecal samples as well in vitro digestive fluids (i.e. SHIME suspension) and will be further applied to discriminate between healthy and diseased individuals in the search for disease-specific biomarkers.An increasing awareness exists that many intestinal diseases and in particular inflammatory bowel disease (IBD) and colorectal cancer (CRC), are intrinsically linked to alterations in the mammalian-microbial symbiosis (known as dysbiosis). In recent years, metabolic fingerprinting has emerged as an innovative approach in disease surveillance, which may ultimately lead to the elucidation of early biomarkers of pathogenesis, metabolites directly correlated with the dysbiosis determinants. In this context, the use of Fourier Transform Orbitrap mass spectrometry allows a true “omics” fingerprint through the analysis of non-invasive samples (stool, exfoliated colonocytes, etc.) derived from patients (IBD and CRC) as compared to healthy individuals. The statistical interpretation of this data, by means of orthogonal partial least squares-discriminant analysis, enables to characterize potential biomarkers. A common pitfall however with metabolomic approaches is the holistic nature of the analysis, i.e. the assurance that the developed method is capable of detecting a variety of metabolites differing in physico-chemical properties, thereby representing the metabolic content of the studied matrix. Therefore, an important first step to obtain this holistic metabolomic method is the development of a targeted analysis enabling the detection of relevant biological metabolites. In this study, over 130 reference compounds (amino-, bile-, hydroxylic- and, carboxylic acids, amines, carbohydrates, short chain fatty acids, N-nitroso compounds, polyols and sterols), which were reported in previous gastrointestinal metabolomic work, were included. This targeted approach enabled profiling of fecal samples as well in vitro digestive fluids (i.e. SHIME suspension) and will be further applied to discriminate between healthy and diseased individuals in the search for disease-specific biomarkers.C