Significantly altered relative abundances of microbial taxa (i.e., Firmicutes (A), Bacteroidetes (B), Actinobacteria (C), and Tenericutes (D)) found across C57BL/6J mice fed a low fat (LF), high fat (HF) diet, or a HF diet containing extractable (HF-EP) or non-extractable (HF-NEP) polyphenols, an equal combination of the EP and NEP fractions (HF-EP+NEP), or grape powder (HF-GP) for 16 weeks. Taxa shown were significantly altered based on Kruskal Wallis test run using QIIME software following rarefaction at 5000 sequences per sample. FDR corrected p values based on this analysis are shown on bottom left of each graph. Means ± SEM (n=8–10) are shown and significant differences between groups are indicated by * (p<0.05), ** (p<0.01), *** (p<0.001), or **** (p<0.0001) using Student’s t-test.