Western nations experience high levels of colon cancer, and carbo-loading gut microbes might explain why, says a new study in mice.
|Scooped by Graham Player Ph.D.|
Westerners’ carb-rich diets have long been linked to high levels of cancer. In country after country where people have switched to Western-style diets heavy in refined sugars such as high fructose corn syrup, the incidence of colorectal cancer has increased, says geneticist Scott Bultman of the University of North Carolina, Chapel Hill.
A study published in “Cell” magazine reported on the link between colon tumors and gut microbes. The researchers surmised that when microbes feast on carbohydrates, the germs must produce a chemical that pushes colon cells lacking the ability to repair DNA mismatches toward uncontrollably multiplying into tumors. To find that chemical, they looked to the colon contents of mice that ate low-carb diets or had received antibiotics. Those mice, compared with mice on regular [high-card] diets, had lower levels of a fatty acid called butyrate, one of the byproducts of microbes’ fermentation of carbohydrates.
The researchers then fed mice butyrate-enriched food. Those mice had more tumor polyps, suggesting that the path from Western diets to colon cancer relies on this bacterially produced chemical.
If the mouse experiments mimic human cancers, then shunning high-carbohydrate, Western diets could allay or prevent the disease for many people, says Bultman. “Following a well-balanced diet, with fewer refined sugars and more fiber, is good for the microbiome and likely has an effect on cancer predisposition.”