Cytokine production by peripheral blood mononuclear cells stimulated with live bacteria of Bifidobacterium longum ES1 and B. bifidum ES2. Panel A, TNF-α production; Panel B, IFN-γ production; Panel C, IL-10 production. Results are expressed as mean ± SD of duplicate measures determined in four independent experiments. Significant differences between means were established by ANOVA with post hoc Fisher's least significant difference (LSD) test at P < 0.05. NS, not significant.