VITAMIN E DELTA-TOCOTRIENOL AND METABOLITE: MODULATION OF GUT MICROBIOTA AND CHEMOPREVENTION OF COLORECTAL CANCER

Colorectal cancer is one of the leading causes of cancer deaths in the United States and multiple modifiable factors contribute to colorectal carcinogenesis. Gut microbiota are believed to play key roles in colon cancer development. Dietary factors may modulate gut microbiota composition, which may potentially have impact on carcinogenesis. Thus, it is reasonable to develop dietary interventions to effectively prevent colorectal cancer development through alteration of gut microbiota. In this thesis, the objective is to evaluate the effect of vitamin E forms i.e., δ-tocotrienol (δTE) and γ-tocotrienol (γTE), and metabolite δTE-13’-COOH (δTE-13’), on gut microbiota in mice. Healthy male Balb/c mice were supplemented with a δTE/γTE mixture or δTE-13’ by gavage for two weeks, while control mice received soybean oil. DNAs were isolated from fecal samples and 16S rRNA gene sequencing was used to evaluate the impact of these compounds on gut microbiota compositions. We observed that δTE/γTE and TE-13’ distinctly changes relative abundance of specific gut microbes without affecting gut microbial composition (beta diversity). These data indicate that δTE/γTE and δTE-13’ can modulate gut microbiota under healthy conditions, which provides insights into new activities of these compounds.