Short summary of content:
The human gut harbours trillions of bacteria that are collectively called ‘microbiota’. This microbiota have been linked to various aspect of human health. The work presented in this thesis focused on studying the associations between the gut microbiota and our human host genotype and energy homeostasis, and how we can modulate the microbiota by consuming a prebiotic and a probiotic food-supplement. For the interpretation of such compositional microbiota data we depend on knowledge of currently cultured gut bacteria, which allows us to make an educated guess on the functioning in the gut yielding interesting and testable hypotheses. However, since the majority of the gut microbiota remains uncultured to date, the last part of this work focuses on methods to provide starting points, by combining different high throughput technologies, with the ultimate goals to more readily cultivate and characterize the currently uncultured bacteria and their genes.