Based on the immunomodulatory properties of butyrate, we quantified hepatic mononuclear cells (MNCs) 7 days after rotavirus infection (time of duct obstruction) by flow cytometric analyses and found significant decreases in helper T cells (TH, CD3+CD4+), cytotoxic T (TC, CD3+CD8+), and NK (CD3–CD49b+) cells, with preferential increases in regulatory T cells (TREG, CD3+CD4+CD25+Foxp3+) and IL-10+ TREG cells, but no effect on macrophages, neutrophils, or dendritic cells (DCs; Fig. 1H and Fig. S3). This evidence concerns the gene FOXP3 and Rotavirus infection.