Integrated Microbiota and Metabolite Changes following Rice Bran Intake during Murine Inflammatory Colitis-Associated...

Area of Science:

• Microbiology
• Metabolomics
• Cancer Research

Background:

• Dietary rice bran shows anti-cancer effects through various mechanisms.
• The impact of rice bran on gut microbiota and metabolites during colon carcinogenesis requires further investigation.
• Understanding these changes in mice and humans can inform colorectal cancer prevention strategies.

Purpose of the Study:

• To investigate how dietary rice bran alters fecal microbiota and metabolites during colon carcinogenesis in mice.
• To compare murine fecal metabolic profiles with human stool profiles after rice bran consumption in colorectal cancer survivors.
• To identify potential biomarkers for rice bran's effects on the gut microbiome.

Main Methods:

• Azoxymethane/dextran sodium sulfate-induced colitis-associated colon carcinogenesis model in BALB/c mice.
• Mice were fed a control diet or a diet with 10% heat-stabilized rice bran.
• Serial fecal collection for 16S rRNA sequencing and non-targeted metabolomics; comparison with human data.

Main Results:

• Rice bran increased fecal microbiota richness and diversity in both mice and humans.
• Key bacterial changes included increased abundance of Akkermansia, Lactococcus, Lachnospiraceae, and Eubacterium xylanophilum.
• Significant metabolic alterations in mice included changes in fatty acids, phenolics, vitamins, monoacylglycerols, and specific compounds like 2-hydroxyhippurate; enterolactone emerged as a novel biomarker.

Conclusions:

• Dietary rice bran modulates the gut microbiome and metabolome, contributing to colorectal cancer protection.
• Murine metabolic changes following rice bran intake complement human metabolic profiles.
• Findings support incorporating rice bran into public health guidelines for colorectal cancer prevention.