1. Laboratory of Animal Physiology, Graduate School of Environmental and Life Science, Okayama University, 1-1-1 Tsushima-Naka, Okayama 700-8530, Japan
2. Research & Development, Ohayo Dairy Products Co., Ltd., 565 Koshita, Naka-ku, Okayama-shi, Okayama 703-8505, Japan
3. Laboratory of Animal Applied Microbiology, Graduate School of Environmental and Life Science, Okayama University, 1-1-1 Tsushima-Naka, Okayama 700-8530, Japan