Ridinilazole is an investigational narrow-spectrum antibiotic primarily used for the treatment of Clostridioides difficile infections (CDI). It works by inhibiting bacterial DNA gyrase, a key enzyme in DNA replication, effectively targeting and inhibiting the growth of C. difficile while sparing the beneficial bacteria in the gut microbiota. This selective action minimizes disruption to the natural gut microbiome, helping to reduce the risk of recurrent infections—a common challenge with broader-spectrum antibiotics. Clinical trials have demonstrated its promise in improving patient outcomes, supporting faster recovery, and preventing relapse by preserving microbial balance essential for long-term gut health. As a targeted therapy, ridinilazole represents a significant advancement in managing CDI, a serious healthcare-associated infection.