Mean frequencies (±SEM) of activated (CD25+Foxp3−) cells among CD4+ cell (A) and CD8+ cell (B) subsets, and inducible T regulatory (CD25−Foxp3+) cells among CD4+ cell subsets (C) and HRV specific IFN-γ producing cells among CD3+CD4+ (D) and CD3+CD8+ (E) T cell subsets. Significant difference (*p < 0.05, **p < 0.01) between HIFM transplanted gnotobiotic pigs fed protein deficient diet (Deficient HIFM) and protein sufficient diet (Sufficient HIFM) groups or between pre- and post-virulent HRV challenge in each group were determined by Mann-Whitney U test. HRV; human rotavirus, Deficient; protein deficient diet, Sufficient; protein sufficient diet, HIFM; human infant fecal microbiota, HIFM; human infant fecal microbiota, PTD; post transplantation day, PVD; post 1st (2nd) vaccination day and PCD; post challenge day.