Synergistic effect of dietary glycerol galactoside and porphyran from nori on cecal immunoglobulin A levels in mice

Abstract

We investigated the effects of dietary porphyran, an indigestible sulfated polysaccharide and the main component of nori, Porphyra yezoensis, and glycerol galactoside (GG; floridoside: 2-O-glycerol-α-D-galactopyranoside, and isofloridoside: 1-O-glycerol-α-D-galactopyranoside), which is abundant in low quality discolored nori and has prebiotic activity, on the concentration of immunoglobulin A (IgA) and microbiota in the cecum of mice. Porphyran increased the IgA concentration and contents in the cecum more than 2-fold. GG alone had little effect on these indices, but synergistically enhanced the IgA-elevating effect of porphyran greatly. Porphyran and GG both altered the cecal microbiota, and an interactive effect of porphyran and GG on the cecal microbiota was observed. Therefore, GG and porphyran are considered to have a synergistic effect on the intestinal immune system through the intestinal microbiota and their metabolites.