How Gut Bacteria and Fiber Team Up Against Cancer

Fiber is commonly known to be an essential component of a healthy diet, but less than 10% of Americans consume the required amount. A new Stanford Medicine study may finally convince us to eat more beans, nuts, cruciferous vegetables, avocados, and other fiber-rich foods. The study, which will be published in Nature Metabolism, revealed the direct epigenetic effects of two typical byproducts of fiber digestion and discovered that some of the gene expression changes had anti-cancer properties (1).

How Gut Bacteria and Fiber Help Fight Cancer by Controlling Our Genes

When we consume fiber, the gut bacteria generates short-chain fatty acids. These chemicals are more than just an energy source for us; they have long been suspected of indirectly influencing gene function. The researchers looked at how the two most frequent short-chain fatty acids in our gut, propionate and butyrate, affected gene expression in healthy human cells, treated and untreated human colon cancer cells, and mice intestines. They discovered direct epigenetic modifications at certain genes that affect cell proliferation and differentiation, as well as apoptosis, or pre-programmed cell death processes – all of which are critical for disrupting or limiting the unregulated cell growth that drives cancer.

Fiber-Rich Foods Help Your Body Fight Cancer

"We discovered a direct link between fiber consumption and anti-cancer gene function modulation, and we believe this is a global mechanism because short-chain fatty acids produced by fiber digestion can travel throughout the body," said Michael Snyder, Ph.D., Stanford W. Ascherman, M.D., FACS Professor in Genetics. "In general, people's diets are low in fiber, which means their microbiome is not getting enough nutrients and cannot produce as many short-chain fatty acids as it should. This is not doing our health any good."

Given the concerning rates of colon cancer in young adults, the study's findings may potentially spark discussion and research into the potential synergistic effects of food and cancer therapy.

"By identifying the gene targets of these important molecules we can understand how fiber exerts its beneficial effects and what goes wrong during cancer," according to Snyder.

References:

1. Short-chain fatty acid metabolites propionate and butyrate are unique epigenetic regulatory elements linking diet, metabolism and gene expression (Nshanian, M., Gruber, J.J., Geller, B.S. et al. Short-chain fatty acid metabolites propionate and butyrate are unique epigenetic regulatory elements linking diet, metabolism and gene expression. Nat Metab (2025). https://doi.org/10.1038/s42255-024-01191-9)

Source-Medindia