Nutrition & DietGut Bacteria Turn Vegetable Nutrients Into Heart and Metabolic Shields
Researchers at Karolinska Institutet have found that gut bacteria can combine nitrate and non-haem iron from vegetables to produce molecules called dinitrosyl iron complexes (DNICs). Published in Cell, the study used mice, cell cultures, bacteria, and human samples to show these compounds are absorbed into the body and travel to organs like the liver and kidneys. When DNIC levels were boosted — either through nitrate-iron supplements or synthetic DNICs — animals showed lower blood pressure, better blood sugar control, improved vascular function, and less liver fat accumulation. Crucially, germ-free mice produced no DNICs at all, confirming gut microbes are essential for their formation. The findings offer a new biological explanation for why vegetable-rich diets protect against cardiovascular and metabolic disease, though human studies are still needed.
