CD4 and colitis: Administration of T. halophilus in mice with DSS-induced colitis upregulated the frequencies of IL-4+ cells in CD4+ T cells (51.27 ± 4.58% vs. 23.96 ± 9.40%, p < 0.001) and in CD8+ T cells (37.27 ± 90% vs. 16.93 ± 6.88%, p < 0.001) (Figure 6A,C).