Dietary fibersexert various biological effects such as anti-cancer effect,improvement of serum lipid levels and intestinal flora, preventionof constipation, immunoregulatory activity etc. It has also beenreported that water-soluble dietary fibers exert strongerimmunoglobulin (Ig) production regulating activity thanwater-insoluble cellulose. Among them, oral administration ofpectin, glucomannan, galactomannnan or chitosans markedly enhancedserum IgA and IgG levels and decreased serum IgE level inSprague-Dawley rats. They also enhanced IgA and IgG productivitiesof spleen and mesenteric lymph node (MLN) lymphocytes, as well asproductivity of cytokines such as interferon-γ and tumor necrosisfactor-α of MLN lymphocytes. These results suggest thatwater-soluble dietary fibers regulate Ig production through theregulation of cytokine production. It has been shown that thesedietary fibers and their sugar components could not stimulate Igproduction of isolated lymphocytes directly. In addition, partiallydigested guar gum exerted weaker dietary effect on Ig productionand lipid metabolism than intact guar gum. These results suggestthat water-soluble dietary fibers exert their biological effectsthrough the interaction of intestinal flora.
Key words: immunogloblin, water-soluble dietary fibers, intestinalfrola, cytokine |
