1. School of Public Health Fudan University/Key Laboratory of Public Health Safety Ministry of Education Shanghai 200032 China
2. State Key Laboratory of Genetic Engineering Zhongshan Hospital and School of Life Sciences Laboratory of Metabonomics and Systems Biology Human Phenome Institute Fudan University Shanghai 200032 China
3. Department of Gastroenterology Zhongye Hospital Shanghai 200003 China
4. Department of Clinical Laboratory Zhongye Hospital Shanghai 200003 China
5. Department of Life Sciences Chalmers University of Technology Gothenburg 412 96 Sweden
6. Department of Public Health and Clinical Medicine Umeå University Umeå 901 87 Sweden
7. Department of Molecular Sciences Swedish University of Agricultural Sciences Uppsala 750 07 Sweden
8. Department of Odontology Section of Molecular Periodontology Umeå University Umeå 901 87 Sweden