ULEI was founded in 1575 and has developed into an outstanding international university, annually hosting more than 3000 international and exchange students each year in its Bachelor and Master programmes, almost 1000 international PhD students and more than 800 international academic staff. ULEI addresses global developments and challenges through an international perspective on law, governance, security, health, and more. Among the research foci, ULEI investigates "Fundamentals of Science", "Translational Drug Discovery and Development", "Bioscience: the science base of health", and "Health, Prevention, and the Human Life Cycle". In the field of bio- and life sciences the Leiden Bio Science Park hosts many international companies and start-ups that are closely linked to the university and play an important role in the university’s international profile.

ULEI is coordinator of MARBLES. ULEI coordinates WP3 and WP8 and contributes to WP2. In WP3, ULEI will identify biosynthetic gene clusters associated with disease-suppressive phenotypes and deliver mutants of disease-suppressive strains and communities obtained from WP2. ULEI will also identify elicitors that activate the production of cryptic compounds and uncover the regulatory networks that control antibiotic production. ULEI will also. In WP2, ULEI will discover disease-suppressive microbes and communities and construct synthetic microbiomes for improved host protection and growth and/or to enhance tolerance of crop plants to abiotic stress. WP8 takes care of the coordination of the MARBLES consortium.