Funding for this research was provided by:
National Natural Science Foundation of China (71704131)
Received: 27 January 2019
Accepted: 16 September 2019
First Online: 15 October 2019
Ethics approval and consent to participate
: This study was approved by the IRB of the National Institute for Nutrition and Food Safety, China Center for Disease Control and Prevention, and University of North Carolina at Chapel Hill. Written informed consent was obtained from all subjects.
: Not applicable.
: The authors declare that they have no competing interests.