Caloric restriction and aging mice gut microbiota. mouse gut metagenome

V3 region of 16S rRNA genes obtained via barcoded 454 pyrosequencing for retrieving patterns of structural changes of gut microbiota from mice fed on low-fat diet or high-fat diet. The extracted DNA from the fecal sample of each mouse was used as template to amplify the V3 region of 16S rRNA gene. The forward primer was 5¡¯-NNNNNNCCTACGGGAGGCAGCAG-3¡¯, and the reverse primer was5¡¯-NNNNNNATTACCGCGGCTGCT-3¡¯, where the underlined sequence is the universal bacterial primer P1 and P2. The NNNNNN is the unique 6nt barcode used to distinguish PCR product from different samples. The products from different samples were mixed at equal ratios for pyrosequencing.