Dietary Rice Bran-Modified Human Gut Microbial Consortia Confers Protection against Colon Carcinogenesis Following...

Area of Science:

• Microbiome research
• Cancer biology
• Nutritional science

Background:

• Rice bran, a byproduct of white rice milling, shows promise in managing colitis and colon cancer.
• Dietary rice bran alters human gut microbiota metabolism.
• Gut microbiota plays a crucial role in colorectal cancer (CRC) development and progression.

Purpose of the Study:

• To investigate if rice bran-modified human gut microbiota protects against chemically induced colon cancer in mice.
• To identify specific microbial and metabolic changes associated with rice bran consumption and their impact on colon carcinogenesis.

Main Methods:

• Fecal microbiota transplantation (FMT) of rice bran-modified microbiota (RMC) from CRC survivors into germ-free mice.
• Induction of colon carcinogenesis using azoxymethane and dextran sodium sulfate (AOM/DSS) in recipient mice.
• Analysis of gut microbiota composition, tumor burden, and key metabolites in the colon.

Main Results:

• Mice receiving RMC exhibited reduced colon neoplastic lesions compared to controls.
• Enrichment of *Flavonifractor* and *Oscillibacter* was associated with colon health, while *Parabacteroides distasonis* depletion correlated with increased tumor burden.
• RMC transplantation increased anti-cancer metabolites (myristoylcarnitine, palmitoylcarnitine) and decreased CRC-implicated metabolites (TMAO, tartarate) in the murine colon.

Conclusions:

• Rice bran-modified gut microbiota from humans confers protection against colon carcinogenesis in a mouse model.
• Specific bacterial taxa and metabolites are modulated by rice bran, influencing cancer development.
• Integrated dietary and FMT strategies show potential for colorectal cancer control, treatment, and prevention.