Effect of Lactobacillus fermentum on Beta2 Toxin Production by Clostridium perfringens

Abstract

ABSTRACTClostridium perfringens, although a member of the normal gut flora, is also an important cause of intestinal disease in animals and, to a lesser extent, in humans. Disease is associated with the production of one or more toxins, and little is known about environmental influences on the production of these toxins. One of the health-promoting effects of lactic acid bacteria (LAB) is the establishment and maintenance of a low pH in the intestine since an acidic environment inhibits the growth of many potentially harmful bacteria. Here, the effect of the LABLactobacillus fermentumon beta2 toxin production byC. perfringensis described. Coculturing ofC. perfringenswithL. fermentumshowed that underin vitroconditions,L. fermentumwas capable of silencing beta2 toxin production byC. perfringenswithout influencing bacterial viability. The reduction in toxin production was shown to be most likely a result of the decline in pH. Quantitative PCR showed that the reduction in beta2 toxin production was due to a decrease incpb2mRNA. These results suggest that in the intestine, the production of beta2 toxin byC. perfringensmight be regulated by other members of the normal intestinal flora.