1. Yakult Central Institute, 5-11 Izumi, Kunitachi, Tokyo 186-8650, Japan
2. Faculty of Research and Development, Yakult Honsha Co., Ltd., 1-1-19 Higashishinbashi, Minato-ku, Tokyo 105-8660, Japan
3. Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo 173-0015, Japan