Gut microbiota and the LPS-rich diet influence in vitro cytokine response of spleen cells. Spleen cells from CV and GF mice fed the low LPS diet (AIN-93G) or LPS-rich diet (ST1) were stimulated with ConA or LPS for 48 h. The production of IFNγ, IL-4, IL-10 and IL-12 cytokines was determined by Luminex analyzer. Results represent the mean (± SE) of at least 6 mice/group. Statistical analyses were performed using one-way analysis of variance (ANOVA) and a post-hoc comparison test (Tukey-Kramer). * indicates p < 0.05 and ** indicates p < 0.01.