Nih 31 mouse rat diet

Male C57BL/6JN and B6D2F1 mice fed either AL or CR were obtained from the aging colony maintained by NIA. After receiving the mice from NIA, animals were housed at the animal facility and maintained under SPF conditions and individually housed in a HEPA barrier environment at the University of Oklahoma Health Sciences Center for at 4-8 weeks before being used in the following experiments. Mice fed ad libitum were fed irradiated NIH-31 mouse/rat diet (Teklad, Envigo), and the CR mice were fed the same diet fortified for micronutrients. CR was initiated by NIA at 14 weeks of age, at a level of 10% restriction, increased to 25% restriction at 15 weeks, and to 40% restriction at 16 weeks of age. Adult (9 months of age) fed AL or CR and old mice (24 months of age) fed AL or CR were fasted overnight, and samples were collected during sacrifice (n=8-10/group). Mice were euthanized by decapitation and fecal material from cecum and colon and colon mucosa were harvested, snap frozen, and stored at −80° C until analyzed. Microbiome, metabolome and transcriptome analysis were done in the same animals. All animal experiments were performed according to protocols approved by the Institutional Animal Care and Use Committee.