Quality of life improvement with soy sauce ingredients, Shoyu polysaccharides, in perennial allergic rhinitis: a double-blind placebo-controlled clinical study.

Soy sauce (Shoyu) is a traditional fermented seasoning of East Asian countries and available throughout the world. We obtained polysaccharides from raw soy sauce, and showed the anti-allergic activities of these Shoyu polysaccharides (SPS) in vitro and in vivo. The present study determined whether oral supplementation of SPS is an effective intervention for patients with perennial allergic rhinitis.