François Leulier is a geneticist by training. After academic studies in Paris, he started his PhD work under the supervision of Pr. Bruno Lemaitre at the CNRS “Centre de Génétique Moléculaire” in Gif-sur-Yvette where he studied the genetic basis of host resistance mechanisms to bacterial infections using Drosophila as a model host. In 2007 he was hired at the CNRS as a staff scientist in the lab of B. Lemaitre and two years later joined the lab of Pr Julien Royet in the IBDML in Marseille. In those laboratories, he followed his studies on the mechanisms underlying host resistance to bacterial infections and started a new research program aiming at deciphering the functional impact of intestinal commensal bacteria species on their host biology. François Leulier was awarded the CNRS Bronze Medal in 2013. In 2014 he was promoted Research Director at CNRS and since 2015 he is a member of the EMBO Young Investigator Program. In 2016, his team showed that intestinal Lactobacilli promote juvenile systemic growth in mice. The Leulier lab at IGFL is currently developing research programs in bacteriology and animal physiology and nutrition to decipher the functional interplays between the intestinal microbiota, lactobacillus strains and chronic undernutrition and their influence on juvenile growth dynamics (including wasting and stunting). Dr Leulier is inventor of 4 patents in the areas of Lactobacillus interventions for improving animal and human health.