Rice bran, removed from whole grain rice for white rice milling, has demonstrated efficacy for the control and suppression of
colitis and
colon cancer in multiple animal models. Dietary rice bran intake was shown to modify human stool metabolites as a result of modifications to metabolism by gut microbiota. In this study, human stool microbiota from
colorectal cancer (CRC) survivors that consumed rice bran daily was examined by
fecal microbiota transplantation (FMT) for protection from
azoxymethane and
dextran sodium sulfate (AOM/DSS) induced colon
carcinogenesis in germ-free mice. Mice transfaunated with rice bran-modified microbiota communities (RMC) harbored fewer neoplastic lesions in the colon and displayed distinct enrichment of Flavonifractor and Oscillibacter associated with colon health, and the depletion of Parabacteroides distasonis correlated with increased
tumor burden. Two anti-
cancer metabolites,
myristoylcarnitine and
palmitoylcarnitine were increased in the colon of RMC transplanted mice.
Trimethylamine-N-oxide (
TMAO) and tartarate that are implicated in CRC development were reduced in murine colon tissue after FMT with rice bran-modified human microbiota. Findings from this study show that rice bran modified gut microbiota from humans confers protection from colon
carcinogenesis in mice and suggests integrated dietary-FMT intervention strategies should be tested for
colorectal cancer control, treatment, and prevention.