Every meal sets off a chain reaction inside the gut, one that depends not only on what we eat, but also on the trillions of microbes that live there. New research from the University of Bonn shows just how crucial those microbes can be. Certain gut bacteria, the study found, help intercept compounds from food before they can transform into potentially cancer-causing chemicals.
Published in The FEBS Journal, the study looked at how microbes process dietary nitrates and nitrites. These compounds occur naturally in vegetables such as spinach, beets and celery, and they’re also added to some processed meats. In certain conditions, they can form substances called nitrosamines, which have been linked to increased cancer risk. But the new findings show that some bacteria act as a natural safeguard against that process.
Researchers identified several key players, including E. coli and species of Lactobacillus and Bacteroides, that can metabolize nitrates and nitrites before they become harmful. This microbial chemistry not only helps protect the body, but it also supports a healthy gut environment where beneficial species can thrive.
“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,” said lead author Uwe Deppenmeier, PhD.
The results highlight just how intertwined diet and the microbiome are. Foods rich in natural nitrates, such as leafy greens, tend to come packaged with antioxidants and plant compounds that support these helpful bacteria. Diets built around fiber-filled vegetables, beans, fruits and whole grains create the kind of environment that allows protective microbes to flourish, while heavily processed or cured meats, when eaten often, may do the opposite.
The research doesn’t point to a single “miracle microbe,” but it does offer a reminder that gut balance is one of the body’s quiet defenses. By feeding beneficial bacteria the nutrients they need, we also help them do the detoxifying work that keeps our internal chemistry in check.
The study was conducted by researchers at the University of Bonn with support from the European Medicines Agency’s GiTOX project and the European Food Safety Authority’s ADME4NGRA project.