The power of metabolite-centric approach was demonstrated on three different types of perturbation; a genetic perturbation in the yeast S. cerevisiae due to the deletion of GDH1 gene encoding NADPH-dependent glutamate synthesis, an environmental perturbation in the yeast due to the availability of oxygen, and a disease-based perturbation due to Alzheimer’s disease. This evidence concerns the gene GLUD1 and Alzheimer disease.