In our laboratory, we have applied lipidomics technology to elucidate the mechanisms of disease progression, and to find novel bioactive lipid, to search diagnostic biomarker for various types of diseases. We usually search for target molecules and obtained proof of concept using highly reproducible animal experimental models, and based on the results, we apply them to human clinical practice. For example, the urinary biomarkers (tetranor-PGDM) for food allergies that we discovered using animal models have been proved to be disease specific and symptom predictable in human clinical studies. In this symposium, I would like to introduce the biomarkers and physiologically active lipids of food allergies, atopic dermatitis, and allergic rhinitis that we have discovered, and their applications to humans.