P1406: TIMING OF EXPOSURE TO INFECTIOUS MICROBIOTA DETERMINES HSC FITNESS. (23rd June 2022) - Jayarajan, J.; Ball, M.; Shah, D.; Lux, S.; Grünschläger, F.; Rodriguez-Correa, E.; Fotopoulou, F.; Knoch, J.; Mikecin, A.-M.; Haas, S.; Schmidt, K.; Rosshart, S.; et al.