Dietary Supplementation with Raspberry Whole Fruit Modifies the Relative Abundance of Fecal Microbial Communities in Obese Diabetic (db/db) Mice

We studied if dietary supplementation with red raspberries can modulate the fecal microbiota of db/db mice. Fecal samples from db/db mice fed a raspberry-supplemented diet (n=12) or an isocaloric control diet (n=15) were used for microbial description using 16S rDNA sequencing with a MiSeq instrument (Illumina). Microbial taxonomy assignments were based on a curated good-quality 16S database (GreenGenes). A total of 2.6 million good-quality sequences (average: 272 nucleotide long) were available for taxonomic and diversity analysis. These sequences were assigned to 3,857 different groups of sequences or Operational Taxonomy Units. There were no significant treatment differences in the two more predominant phyla Firmicutes and Bacteroidetes, each comprising of many different species of bacteria. Interestingly, when looking at deeper taxonomic levels within each phylum, raspberry supplementation was associated with higher relative proportions of Lachnospiraceae, a group that has been shown to be depleted du...