Obesity has been linked to diabetes through numerous physiological and metabolic changes. We previously reported that the dietary tocotrienols (TT) favor the abundance and diversity of beneficial microbiome in obese male mice. In the present study, we further examined the combined effect of TT and green tea polyphenols (GTP) on the gut microbiome of obese male mice. We hypothesized that this combination would have a beneficial effect on the composition and function of the gut microbiome compared to either TT or GTP individually.
Male C57BL/6J mice fed a high fat diet (HFD) were assigned to a 2 (no TT vs. TT) × 2 (no GTP vs. GTP) factorial design: HFD, HFD+TT (400 mg TT/kg diet), HFD+GTP [0.5% (weight/volume)], and HFD+TT+GTP for 14 weeks. 16S rRNA gene sequencing from fecal samples was analyzed.
Across all groups, the most abundant phyla were Verrucomicrobia, Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria. Redundancy analysis showed a significant difference in the gut microbiome profile between mice fed with different diets. The linear discriminant analysis effect size method revealed that GTP supplementation increased the relative abundance of Blautia and Enterobacteriaceae, and this increase was augmented in the HFD+TT+GTP group. The relative abundance of Adlercreutzia was increased only in the HFD+TT+GTP group.Results of metagenomic function showed the addition of TT+GTP to HFD increased amino acid metabolic pathway, while decreased carbohydrate metabolic pathway.
Our results suggest that supplementation of the HFD with TT and GTP modifies both the composition and function of the gut microbiome.