Oral administration of alginic acid oligosaccharide suppresses IgE production and inhibits the induction of oral tolerance

We have found that alginic acid oligosaccharide (ALGO) enhanced Th1 by promoting IL-12 production, suggesting that ALGO can be applied as an anti-allergic food. In this study we examined both positive and negative functions of ALGO. First we investigated the anti-allergic activity of ALGO, as a positive function, when orally administered. IgE production was significantly inhibited in mice fed ALGO as compared to control mice. This result indicates that ALGO had anti-allergic activity even when orally administered. On the other hand, we also found a negative function of ALGO. Oral co-administration of a protein antigen and ALGO inhibited the induction of oral tolerance to the protein. These data indicate the potential of ALGO as an anti-allergic food material and the necessity of further examination to determine a safe method application.