Understanding the fate of nutritional components in the body is crucial, because processes such as their release from the nutritional matrix, their absorption, distribution, and possible metabolism and excretion are important determinants of their ultimate effects. In addition, knowledge of these processes can help us to detect and prevent deficiencies. Within this research theme, bio-analytical research methods are developed and applied with the aim of studying the kinetics and metabolism of nutrients.
Various factors, depending on both the nutritional matrix and the consumer, ultimately determine the fate and hence the effects of macro and micronutrients in the body. Sometimes these processes are rather straightforward, such as the way how protein is digested to amino acids, which after their absorption serve as building blocks for muscle tissue and enzymes. However, more often the situation is more complex, as nutrients are usually part of large dynamic networks and can undergo extensive metabolism such as is the case for e.g. dietary lipids and several micronutrients. This may be further complicated by inter-individual genetic variation in transport and/or enzymes that are required for nutrient uptake and metabolism. This is increasingly understood for e.g. vitamin D and n-3 fatty acids, where polymorphisms can directly affect blood values and thus ultimately have an impact on health effects. It is therefore important to develop bio-analytical research methods that allow studying all aspects of the kinetics and metabolism of nutrients.
Metabolism of n-3 fatty acids and their relation with inflammation.
Fish oil is rich in essential n-3 fatty acids, which are required for e.g. brain development and function. Evidence suggests that n-3 fatty acids also have anti-inflammatory properties, which may depend on their conversion into metabolites such as docosahexaenoyl ethanonamide (DHEA). In this project, we investigate the COX-2 mediated conversion of DHEA into novel oxygenated molecules such as 13-hydroxy-DHEA (13-HDHEA) and 16-HDHEA. Using various mass spectrometry (MS) based approaches (LC-HRMS for metabolite identification, LC-MS/MS for sensitive quantification) we study the formation and effects of DHEA metabolites.
Bioavailability of gamma-aminobutyric acid.
Although known as a neurotransmitter, gamma-aminobutyric acid (GABA) may also be considered a nutrient as it is present in e.g. potatoes and tomatoes and produced by our intestinal microbiota. Interestingly, evidence suggests that GABA has beneficial metabolic and physiological effects on glucose homeostasis and blood pressure regulation. In this project, we investigate the relative bio-availability of GABA from supplements compared to food sources. Using a LC-MS/MS based bio-analytical research method we study the nutri-kinetics of GABA in humans.
Optimization of micronutrient status through nutrition.
Micronutrient deficiencies are still present in the Netherlands, which may be caused by inadequate nutrition, malabsorption or associated with the use of medication. At the same time, excessive supplement use may lead to adverse health effects, such as neuropathy, and may be a potential risk factor for cancer. In this research field, we aim to identify risk groups for deficiencies as well as investigate the relation between dietary micronutrient intake and biomarkers of micronutrient status. This topic is closely involved in NutriProfiel, a personalized dietary advice service that is offered to patients of Gelderse Vallei Hospital within the Nutrition & Healthcare Alliance.