RAG1 and colitis: To directly link our in vitro results with those obtained in the model of T cell transfer colitis, we collected fecal samples from representative Rag1-/- mice with a presumably dysbiotic microbiota (DYS) prior to bacterial administration and from T cell transplanted mice with or without commensal enrichment after development of colitis (DYS + TC, DYS + TC + BV, DYS + TC + EC).