Gut Bacteria Fuel Colon Cancer Growth, Study Finds

Scientists have uncovered evidence linking Western diets to an increased risk of colorectal cancer, with specific gut bacteria playing a crucial role. Published in the journal Gut, the study indicates that certain intestinal bacteria transform bile acids into compounds that encourage tumor proliferation. This finding offers potential new avenues for preventing colorectal cancer.

Western diets, characterized by high fat and red meat intake with low fiber, have been associated with higher colorectal cancer risk. Researchers utilized experiments with pigs, mice, and human colon tissue, alongside microbiome data from thousands of individuals.

The study identified deoxycholic acid (DCA), a secondary bile acid produced by gut bacteria, as a significant factor. Elevated DCA levels were observed to stimulate colon cell growth, fostering an environment that could lead to tumor development. Experiments showed pigs on a Western diet had higher DCA and more severe cancer signs.

Further tests confirmed that introducing DCA-producing bacteria increased colon tumors in mice, while altering bacteria to prevent DCA production reduced tumors. Analysis of human stool samples indicated a higher prevalence of DCA-related bacteria in individuals with colorectal cancer.

These insights may enable stool testing to identify high-risk individuals. Future strategies could involve dietary changes or treatments targeting specific gut bacteria to lower disease risk, though further human studies are needed.