Funding for this research was provided by:
Japan Society for the Promotion of Science (15K06912, 15K08747)
Ministry of Health, Labor and Welfare of Japan (H25-Food-General-006)
Received: 8 July 2019
Accepted: 23 September 2019
First Online: 5 December 2019
Ethics approval and consent to participate
: All participants provided informed consent. This study was approved by the ethics committees of Jichi Medical University (approval number: Gene 15-22; 2015), Asahikawa Medical University (approval number; No. 1660-3), and National Institute for Environmental Sciences (approval number: 2013-9R).
: All participants in this study provided consent for their data to be used in publications.
: The authors declare that they have no competing interests.