Effects of Nicotinamide Riboside on Bacterial Respiratory Epithelial Infections: Preclinical Findings

Synopsis

This study found that during infection, lung cells experience a breakdown in the NAD+ salvage pathway, which reduces NAD+ production—a molecule crucial for energy metabolism and immune defense. When key NAD+ enzymes were blocked, bacterial growth increased, showing that this pathway helps protect against infection. Boosting NAD+ in host cells with precursors like nicotinamide riboside (NR) or NMN increased intracellular NAD+ and reduced bacterial replication, while NR had little effect on bacteria grown alone, indicating that its protective effect depends on the host cells. Restoring NAD+ levels or directly adding NAD+ suppressed bacterial replication, while enhancing bacterial energy metabolism reversed this effect. In contrast, NAD+ boosted the growth of some other respiratory microbes, suggesting a specific antibacterial action against Spn. The results show that maintaining healthy NAD+ metabolism, including through NR supplementation, strengthens the body’s natural defense against pneumococcal infections, highlighting a new metabolic strategy to fight pneumonia.

Journal

Nature Communications