Dysbiosis affects the total number of B cells in spleen cells but not in MLNs. Cell enumeration by flow cytometry was performed on whole-cell isolates from dissected spleen and MLNs of control and ampicillin-treated mice at 6 weeks of age, before FVIII infusion (n = 9 for each cohort). B220⁺ B cells (A) and CD4⁺ T cells (B) as a proportion of total cells. Other cells analyzed include: CD25⁺FoxP3⁺ (C) and CD25⁻Foxp3⁺ (D) T cells represented as a proportion of total CD4⁺ cells, and CD11c⁺ DCs (E) as a proportion of total immune cells, and CD103⁺ cells (F) as a proportion of total CD11c⁺ DCs. The means and standard deviations within each immunological organ were compared by using an unpaired, 2-tailed Student t test. *P < .05.