Short chain fatty acids (SCFAs), the microbial metabolites of fermentable dietary fibers exert
multiple beneficial effects on mammals including humans. We examined the effects of
fermentable dietary fibers on suppressor of cytokine signaling 1 (SOCS1), a negative regulator
of inflammatory signaling, on the intestinal epithelial cells of the mouse colon and human
intestinal Caco-2 cells, specifically focusing on the role of SCFAs. Feeding fermentable fibers,
guar gum (GG) and partially hydrolyzed GG (PHGG) increased SOCS1 expression in the colon
and the cecal pool of some SCFAs including acetate, propionate, and butyrate. The antibiotic
administration abolished the GG-mediated SOCS1 expression in the colon. In Caco-2 cells,
butyrate, but not other SCFAs, increased SOCS1 expression. Taken together, fermentable fibers
such as GG and PHGG upregulate the colonic SOCS1 expression, possibly through the
increased production of butyrate in mice and can be a potential tool in the fight against
inflammatory diseases.