Fig. 7

Short-chain fatty acids of different chain lengths (C2–C6) alter IL-8 and MCP-1 production according to their effects on histone acetylation. Here 5 mM each of acetate (C2), propionate (C3), butyrate (C4), valerate (C5), and hexanoate (C6) were added to Caco-2 cells for 24 hr. IL-1β was then given for a further 24 hr. Acetate and hexanoate had little effect on acetylation and on chemokine expression (p, not significant). Valerate and propionate altered both chemokine secretion (p < 0.01) and histone acetylation, but the effects were less than those of butyrate. Bars represent standard deviations of three different wells for each point. The data are representative of three experiments.