Gut bacteria metabolize nitrogen compounds to prevent cancer-causing nitrosamines

Nitrogen metabolism of gut bacteria can provide health benefits. Specifically, gut microbes metabolize dietary nitrates and nitrites and prevent the formation of cancer-causing compounds called nitrosamines. New research published in The FEBS Journal sheds light on these processes and pinpoints which types of bacteria are most important.

Investigators found that Escherichia coli-and to a lesser extent, species of the genera Lactobacillus, Bacteroides and Phocaeicola-can efficiently metabolize different forms of nitrogen, thus preventing carcinogenic nitrosamine formation. They also demonstrated that this bacterial processing is critical to enable microorganisms to survive and colonize the intestinal tract, likely preventing harmful changes in the composition of the gut microbiota.

The findings highlight the importance of the gut microbiota in preventing the formation of harmful nitrogen metabolites, potentially decreasing the risk of certain cancers. The study also illustrates how the microbiota facilitates crosstalk between our diet and the gut, thus having important implications for both health and disease.

The discovery that specific gut bacteria rapidly metabolize nitrite suggests a protective mechanism through which the microbiota contributes to the maintenance of intestinal and systemic health."

Prof. Uwe Deppenmeier, corresponding author, University of Bonn, Germany