3,3′-Diindolylmethane induces immunotoxicity via splenocyte apoptosis in neonatal mice

► We explore the immunotoxic effects of DIM in a neonatal mouse. ► DIM-induced immunotoxic effects include decreases in various immune cells, induction of white pulp atrophy and increase apoptosis in spleen. ► Apoptosis was notably promoted by up-regulating caspase-3 activity and by the change in the ratio of Bcl-2/Bax activities. ► Oral administration of DIM led to deterioration of RV-induced intestinal disease and delayed viral clearance in the intestine. ► DIM induces immunotoxicity in spleen and hampers efficient RV clearance in the intestine.