As compared with placebo , the S. boulardii group showed a significant decrease in blood and tissue levels of proinflammatory cytokines interleukin-8 ( IL-8 ) and tumor necrosis factor - ( P < 0.001 ) and an increase in anti-inflammatory IL-10 levels , as well as an increase in the tissue IL-10 / IL-12 ratio ( P < 0.001 ) .