Conflicts of Interest
This study was performed jointly by RIKEN and Meiji Co., Ltd. Y.W. holds the position of joint research chair, and A.S. is a leading researcher in joint research. Y.W. and A.S. received funding for this study from Meiji Co., Ltd. C.O., K.N., and M.N. are employees of Meiji Co., Ltd., who provided the chocolate used in this study. E.K., K.W., E.Y., and K.M. declare no conflicts of interest.