Stratified medicine has been successfully used in many areas of medicine, perhaps most notably oncology. There is now both a growing evidence base and mounting enthusiasm, supported at a governmental level and across industry, academia and clinical medicine, to apply this approach to neurodegenerative illnesses, including dementia, as these provide the greatest clinical and social challenge of our times. In this article we consider definitions of stratified medicine, look at its application in other medical specialties, review the national context in the UK and consider the current state, future potential and specific considerations of applying stratified medicine to dementia.

Non-alcoholic fatty liver disease (NAFLD) is now a major public health concern with an estimated prevalence of 25–30% of adults in many countries. Strongly associated with obesity and the metabolic syndrome, the pathogenesis of NAFLD is dependent on complex interactions between genetic and environmental factors that are not completely understood. Weight loss through diet and lifestyle modification underpins clinical management; however, the roles of individual dietary nutrients (e.g. saturated and n-3 fatty acids; fructose, vitamin D, vitamin E) in the pathogenesis or treatment of NAFLD are only partially understood. Systems biology offers valuable interdisciplinary methods that are arguably ideal for application to the studying of chronic diseases such as NAFLD, and the roles of nutrition and diet in their molecular pathogenesis. Although present in silico models are incomplete, computational tools are rapidly evolving and human metabolism can now be simulated at the genome scale. This paper will review NAFLD and its pathogenesis, including the roles of genetics and nutrition in the development and progression of disease. In addition, the paper introduces the concept of systems biology and reviews recent work utilising genome-scale metabolic networks and developing multi-scale models of liver metabolism relevant to NAFLD. A future is envisioned where individual genetic, proteomic and metabolomic information can be integrated computationally with clinical data, yielding mechanistic insight into the pathogenesis of chronic diseases such as NAFLD, and informing personalised nutrition and stratified medicine approaches for improving prognosis.