Anti‐inflammatory effects of sodium butyrate on human monocytes: potent inhibition of IL‐12 and up‐regulation of IL‐10 production

ABSTRACT Cytokines are critical in regulating unresponsiveness versus immunity towards enteric antigens derived from the intestinal flora and ingested food. There is increasing evidence that butyrate, a major metabolite of intestinal bacteria and crucial energy source for gut epithelial cells, also possesses anti‐inflammatory properties. Its influence on cytokine production, however, is not established. Here, we report that butyrate strongly inhibits interleukin‐12 (IL‐12) production by suppression of both IL‐12p35 and IL‐12p40 mRNA accumulation, but massively enhances IL‐10 secretion in Staphylococcus aureuscell‐stimulated human monocytes. The effect of butyrate on IL‐12 production was irreversible upon the addition of neutralizing antibodies to IL‐10 or transforming growth factor β1 and of indomethacin. In anti‐CD3‐stimulated peripheral blood mononuclear cells, butyrate enhanced IL‐10 and IL‐4 secretion but reduced the release of IL‐2 and interferon‐γ. The latter effect was in part a result of suppressed IL‐12 production but also a result of inhibition of IL‐12 receptor expression on T cells. These data demonstrate a novel anti‐inflammatory property of butyrate that may have broad implications for the regulation of immune responses in vivoand could be exploited as new therapeutic approach in inflammatory conditions.