This report is a summary of my research work since my thesis. It presents my research themes, main results, collaborations and outlines my future projects. During my doctoral and post-doctoral experiences in Paris and London, my research focused on innate T cells, such as iNKT and T γδ cells, and on characterizing their development and regulation by endogenous mechanisms.Since joining INRAE as a research fellow, I have been studying the impact of the gut microbiota on lymphoid cells and developing the microbiota/ immunity axis within my team. My objectives are to identify new commensal regulatory bacteria and to dissect the effect of metabolites produced by the microbiota. My current research targets include environmental factors that could influence the microbiota/ immunity axis. In particular, the challenge is to understand the role of diet on the immune system.