The human gut microbiota has been linked with incidence and progression of non-communicable diseases and their risk factors. Moreover, diet has been identified as an important modulator of microbiota composition and function, but responses vary between individuals. Underlying mechanisms of diet x microbiota interactions remain to be elucidated to provide a foundation for tailored dietary strategies for personalized precision nutrition. The aim in this proposal is to investigate how gut microbiota interacts with diet and the role of such interactions on cardiometabolic risk factors. The aim is further to dissect the underlying mechanisms through extensive metabotyping using metagenomics and metabolomics combined with lifestyle data in a free-living prospective cohort subset. We hypothesize that gut microbiota x diet interactions is a major determinant of the metabotypes and that such distinct metabotypes could be reflected by predictive biomarkers that can be used to tailor personalised dietary interventions to improve molecular phenotype among subjects at elevated risk of CVD. We will test the hypothesis by conducting a dietary intervention rich in fermentable vs non-fermentable cereal fibre among subjects with signs of metabolic syndrome with distinct differences in their pattern of microbiota and microbiota-derived metabolites. The consortium connects several complementary competences from both academia and industry in this multidisciplinary, transnational proposal.