Gut commensal <i>Bifidobacterium longum</i> confers resistance to <i>Salmonella</i> Typhimurium and <i>Shigella flexneri</i> in a <i>Caenorhabditis elegans</i> model

Gut infections caused by <i>Salmonella</i> and <i>Shigella</i> are major global health threats. As an alternative to novel drug discovery, which is time-consuming and faces several challenges, this study explores the potential of gut bacteria to protect against these pathogens. We identified <i>Bifidobacterium longum</i>, a common gut microbe, which can significantly reduce infection by both <i>Salmonella</i> and <i>Shigella</i> in a lab setting and in a simple animal model. The bacterium functions by creating an environment that is hostile to pathogens and by modulating the host's immune responses. These findings suggest that <i>B. longum</i> could be developed as a natural, non-antibiotic treatment to control or reduce these enteric pathogen infections. This approach opens the door to using probiotics as effective tools in the global fight against antibiotic resistance.