Abstract
Recent epidemiological findings concerning the relation between intestinal microflora and allergic disorder support an idea that lactic bacteria, bifidobacteria and lactobacilli, colonized in the human intestinal lumen, would contribute to prevention of allergy. Furthermore, some studies reported that lactic bacteria suppressed Th2 type immune response associated with development of allergy through enhancement of Th1 response. It is well known that intake of indigestible oligosaccharides is able to increase indigenous lactic bacteria, especially bifidobacteria. We investigated effects of raffinose, a kind of oligosaccharide, on Th1/Th2 immune response using ovalbumin specific T-cell receptor transgenic mice. Feeding raffinose to the transgenic mice significantly reduced IL-4 production from mesenteric lymph nodes cells and serum IgE response, which were induced by ingestion of ovalbumin. These results suggest that intake of raffinose suppresses unfavorable Th2 response induced by oral antigens, although types of intestinal bacteria linked to the change of rodent immune response remain unknown because feeding raffinose did not influence bacterial counts of cultivable bacteria in the ceca of the mice.
