Inhibitory effect of Lactobacillus plantarum isolated from intestinal microbiota on Clostridium difficile infection

Abstract

Clostridium difficile infection (CDI) is one of the most widely known nosocomial infections. The dysbiosis of gut microbiota due to antibiotic use is the leading cause of CDI

people with relatively healthy gut microbiota do not typically become infected with CDI. It is, therefore, necessary for researchers to find a specific bacterium that inhibits CDI among healthy gut microbiota to regulate it. However, there have been few studies about CDI-resistant strains among healthy gut microbiota. Therefore, this study aims to verify the inhibitory effect of single strains isolated from normal individuals on CDI and to determine the underlying mechanism. Through previous studies, three strains isolated from healthy Koreans with C. difficile inhibitory effects were selected. The CDI inhibitory effects of the three strains were confirmed through animal experimentation. CDI inhibition was assessed by post-infection weight change, C. difficile colony forming unit (c.f.u.), and the toxin A&B measured value. The feces collected in the animal experiment were used to analyze the changes and status of gut microbiota and gut metabolome. As a result of this experiment, a significant inhibition of CDI was observed in the group to which Lactobacillus plantarum SNUG 10271 was administered. Gut microbiota analysis showed that Ruminococcaceae and Coprococcus showed high abundance in the L. plantarum SNUG 10271 group and was negatively correlated with C. difficile. Gut metabolome analysis showed that the concentration of deoxycholic acid (DCA) was significantly higher in individuals with inhibitory effects. These results confirmed the possibility of CDI inhibition of a single strain isolated from healthy individuals. We also found information on Ruminococcaceae, Coprococcus, and DCA that will be necessary to understand the mechanism of CDI inhibition.