gut metagenome

Seven-week-male Sprague-Dawley (SD) rats (specific-pathogen-free SPF grade) purchased from Beijing Vital River Laboratory Animal Technology Co., Ltd. (Beijing, China) were raised in SPF laboratory room with feed and water. After 1 week of acclimatization with AIN-93 standard maintenance chow, the rats were randomly divided into 4 groups according to body weight (12 rats per group, three rats per cage): a basal diet group (Ctrl group), a low fructose diet group (LFD group), a middle fructose diet group (MFD group), a high fructose diet group (HFD group). The diet was purchased from Beijing Keo Collaborative Feed Co., Ltd. The rats were feed with different diets for another 8 weeks. The body weight and feed intake were recorded every week. At the end of the experiment rats were anaesthetized by cervical dislocation after briefly carbon dioxide sedation. Blood was collected by cardiac puncture, centrifuged at 4000 rpm for 10 min and stored at minus 80 degrees Celsius. Colon length was measured. Colonic mucosa, colonic tissue and colonic contents were collected and rapidly frozen in liquid nitrogen. Samples were stored at minus 80 degrees Celsius for further study. All animal studies were approved by the Ethical Committee for Animal Experimentation of the Academy of National Food and Strategic Reserves Administration with utilization permission from Beijing Municipal Science and Technology Commission.