One of the world’s most serious public health problems is Antibiotic resistance, and one way to alleviate it is supplementary probiotic medicines. An excellent example of how supplementary probiotic therapy might help avoid illness is Clostridioides difficile infection (CDI). Lactobacillus reuterin, a human-derived probiotic that produces the antibacterial agent reuterin and has been shown to inhibit C. difficile colonization in antibiotic-treated fecal microbiota communities. The mechanism of inhibition, however, remains unknown. Reuterin suppresses C. difficile spore outgrowth and vegetative cell growth, but has no effect on C. difficile germination or sporulation, according to researchers’ findings. It was discovered by the researchers that reuterin activated reactive oxygen species (ROS) in C. difficile, resulting in a concentration-dependent loss in cell viability that was restored by the antioxidant glutathione, which was consistent with previous research. The susceptibility of vegetative C. difficile to vancomycin and metronidazole therapy was increased by Sublethal reuterin concentrations and the same decreased C. difficile toxin production. In a human intestinal entered model, the researchers also showed that reuterin protects cells from C. difficile toxin-mediated cellular damage. Overall, the findings revealed that ROS are important mediators of reuterin activity and that L. reuterin production can be used as a therapy in a clinically relevant paradigm.