NO and cytokine secretion profiles of RAW264.7 macrophages stimulated by bifidobacterial strains. RAW264.7 macrophages were cocultured with B. adolescentis IF1-11, B. adolescentis IF1-03 or B. animalis subsp. lactis Bb12 for 24 h at the indicated ratios. The supernatant NO (μM) was analyzed by the Griess assay (A) and cytokines by ELISA (B). All strains were prepared at a density of 5 × 105–107 cfu/mL in DMEM, and RAW264.7 macrophage cells were at 5 × 105 cell/mL. Ratios—1:1, 5 × 105 cfu:5 × 105 cell; 10:1, 5 × 106 cfu:5 × 105 cell; 50:1, 2.5 × 107 cfu:5 × 105 cell; 100:1, 5 × 107 cfu:5 × 105 cell, per reaction respectively. Data are shown as mean ± SD for three independent experiments, significant differences in each ratio group are labelled with different letters by one-way ANOVA, p < 0.05. TNF-α: Tumor Necrosis factor, IL-6: Interleukin 6, IL-10: Interleukin 10, TGF-β: Transforming growth factor β.