💊 Magnesium Against Colorectal Cancer?

A study conducted by a team from the Vanderbilt University Medical Center focused on individuals who had previously presented with colorectal polyps. As part of a randomized, double-blind trial, participants received either a magnesium supplement or a placebo. The objective was to observe the effect of this supplementation on their gut microbiome, that is, the billions of microbes hosted by our digestive system.

The obtained data indicate that magnesium intake increases the presence of two specific types of bacteria, Carnobacterium maltaromaticum and Faecalibacterium prausnitzii. These microorganisms are recognized for their ability to synthesize vitamin D directly in the digestive tract, independently of sun exposure. Produced on-site, this vitamin does not enter the bloodstream but exerts a local action that could prove protective.


The investigation specifies that these consequences are not uniform. They depend in particular on the function of a gene called TRPM7, which regulates how our body absorbs magnesium and calcium. For individuals in whom this gene functions correctly, the magnesium supplement stimulates beneficial bacteria. In contrast, when its function is less efficient, it can reduce the abundance of F. prausnitzii in the rectal mucosa.

The scientists also observed a disparity between men and women, the effect being primarily observed in the latter. They estimate that this difference could stem from the influence of female hormones, such as estrogens, on the transport and use of magnesium by the body's cells.

Monitoring participants for several years after the end of the trial allowed for another observation. A high presence of the bacterium F. prausnitzii in the rectal mucosa was linked to an almost tripled risk of polyp recurrence. This finding shows that the relationship between these bacteria and gut health is nuanced and calls for further investigation.

This work opens the way to more individualized strategies for the prevention of colorectal cancer, especially in at-risk individuals. It illustrates the close interactions between our diet, the supplements consumed, and the delicate balance of our gut flora. In the future, understanding these mechanisms could help develop nutritional recommendations tailored to each profile.