Obesity is a serious problem in society today [1,2]. It might seems to have been caused simply by excess consumption of food compared to energy expenditure but obesity is actually a complex metabolic disorder centred on adipose lipid metabolism and cellular signalling systems linked to it [3]. Understanding the biology of adipose tissue (AT) is very important for the identification of novel and potential therapeutic targets in order to prevent and treat obesity-related disorders [4]. We utilized analytical approach liquid chromatography coupled to mass spectrometry (LC-MS) to study adipose tissue metabolism. Also, we were especially interested in the effect of omega-3 polyunsaturated fatty acids (PUFA) on that metabolism. Rodent and cell line experiments were performed and analyses were done of white adipose tissue (WAT), serum/plasma samples or cells as well as milk samples from mothers. At first, we established several ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) methods for analysis of acylcarnitines (AC), amino acids (AmA) and other metabolites. Importantly, these methods were able to distinguish isobaric species of AC which is not usually possible. Using these approaches we uncovered several acylcarnitines, i.e. long chain AC, carnitine, acylcarnitine C4 and...

Inflammatory bowel disease is a serious condition with an incomplete etiology and pathogenesis. In this thesis, a mouse model of sodium dextran sulfate-induced inflammation was used to study different changes in the metabolism of germ-free and conventionally raised mice due to the development of the inflammatory process. NMR metabolomics of fecal, urine and serum samples, combined with uni- and multivariate statistical analysis, were used to characterize the changes. It was shown that the metabolic signature differs between germ-free and conventional mice. In germ-free mice, significant amounts of carbohydrates were found in feces. Their levels decreased during inflammation as they were excreted in urine. In contrast to conventional mice, germ-free mice also excreted large amounts of amino acids in feces during the developing inflammation. Disorders of sugar and protein metabolism found in germ-free mice indicate severe malnutrition caused by inflammation. The results show that the presence of a microbiome represents a protective mechanism against significant disruption in the body. A stability study of fecal extracts of healthy conventionally colonized mice confirmed that none of the identified and quantified metabolites showed significant systemic changes in several consecutively collected...