Article type: News and Views: Groundbreaking Discoveries in ImmunologyTitle: Uncovering the influence of diet and gut microbiota in human serum metabolomeAuthors: David Obeso1,2‡, Elisa Zubeldia-Varela1,2‡ and Alma Villaseñor11Instituto de Medicina Molecular Aplicada (IMMA), Departamento de Ciencias Médicas Básicas. Facultad de Medicina. Universidad San Pablo-CEU, CEU Universities, Madrid, España.2Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, Madrid, España.‡: These Authors have equally contributedCorrespondence: Alma Villaseñor, Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, Madrid, EspañaEmail address:alma.villasenor@ceu.esKeywords: Metabolomics, Diet, Microbiota, Allergy, Serum, MetabolomeAbbreviations: MS, mass spectrometry; LC, liquid chromatography; short chain fatty acids (SCFA)Acknowledgement: We would like to thank Anna Głobińska for her assistance in generating the graphical figure. AV Gratefully acknowledges the Martín-Carbajo family for supporting her scientific development through the X Mario Martín Velamazán award.Author contributions: D.O., E.Z-V. and A.V contributed to the writing of the manuscript and have given approval to the manuscript. A.V. supervised the final version.