Researchers at Karolinska Institutet have discovered that gut microbes can convert nitrate and non-haem iron from dietary sources, such as vegetables, into dinitrosyl iron complexes (DNICs). These molecules, which can be absorbed and transported to organs like the liver and kidneys, were found to be entirely absent in germ-free mice, indicating that gut bacteria are essential for their formation. The study, published in Cell, utilized experiments with mice, cells, bacteria, and human samples to detect DNICs in various tissues, revealing a previously unknown mechanism by which gut microbiota may influence systemic health.
Further investigation demonstrated that elevated DNIC levels, achieved through dietary supplements containing nitrate and iron or synthetic DNIC administration, were associated with improved health markers in an animal model of cardiovascular and metabolic disease. Specifically, higher DNIC levels correlated with reduced blood pressure, enhanced vascular function, better blood glucose regulation, and decreased hepatic fat accumulation. The researchers suggest that this mechanism may help explain the protective effects of a vegetable-rich diet against cardiovascular and metabolic disorders, although they note that additional human studies are needed to fully elucidate the process. Future research aims to develop methods for measuring DNIC levels in humans and to explore the potential of dietary or microbiota interventions to modulate DNIC production for disease prevention. Source