Abstract A020: Exploring the effects of resveratrol on the gut microbiome in high fat diet-fed BRAFV600E mutant mice


 The polyphenol resveratrol, widely known for its cancer protective activities has been shown to protect against the pro-tumorigenic effects induced by high-fat diets (HFD) in mouse models of colorectal cancer (CRC). Although, the mechanisms of actions of this compound in humans still remain elusive, recent studies suggest its effects may be mediated partly through its interaction with the gut microbiota. Here we sought to determine the changes induced by HFD on the intestinal microbiome and the impact of resveratrol supplementation on these alterations in a mouse model of BRAFV600E mutant CRC.
 BRAFV600E; BRAFWT (wild-type) mice were randomised into 8 groups and fed either a standard diet or HFD supplemented with low or high-dose of resveratrol (0.7mg/kg/day and 14mg/kg/day, respectively) for 6-weeks. The mouse faecal microbial profile was then assessed by targeting the V3-V4 area of the bacterial 16S rRNA gene.
 Consumption of HFD was associated with significant alternations in the gut microbiome composition in both BRAFV600E and BRAFWT based on beta-diversity analysis (PADONIS<0.05). HFD increased the Firmicutes and Clostridia abundance in BRAFWT compared to animals on a standard diet (P<0.01, P<0.008 respectively), while in BRAFV600E mice, alterations were observed in lower taxonomic levels including the enrichment of Faecalibaculum (P<0.02) and growth inhibition of Lactobacillus johnsonhii (P<0.05). High-dose resveratrol resulted in significant differences in the microbial composition compared to HFD-treated group in the BRAFV600E mice (PADONIS<0.05) but not in BRAFWT . Resveratrol administration did not counteract the HF-induced taxonomic changes but high-dose resveratrol changed Muribaculum, and UBA181 genera abundances in BRAFV600E mice (P<0.001 and P<0.05 respectively) compared to HF-treated mice. Low dose resveratrol had no significant effects on bacterial abundance in both BRAFV600E and BRAFWT mice. It was also observed that BRAFV600E mutation influenced the gut microbiome independently of diet based on beta and alpha-diversity (PADONIS<0.05, PChao1<0.05 respectively).
 Resveratrol administration modified the gut microbiota composition of BRAFV600E mice but did not completely reverse the HFD-induced changes indicating that alternative mechanisms may contribute to the protective effects of resveratrol in this mouse model.
 Citation Format: Despoina Theofanous, Hong Cai, Karen Brown. Exploring the effects of resveratrol on the gut microbiome in high fat diet-fed BRAFV600E mutant mice [abstract]. In: Proceedings of the Second Biennial NCI Meeting: Translational Advances in Cancer Prevention Agent Development (TACPAD); 2022 Sep 7-9. Philadelphia (PA): AACR; Can Prev Res 2022;15(12 Suppl_2): Abstract nr A020.