A structural biology approach has identified a conserved region common to multiple Clostridium toxins. Specific mutations of the protein sequence in this region prevent the toxins from entering into intestinal cells, thereby preventing widespread tissue damage. These recombinant Clostridium toxins may be used to create a multivalent vaccine to protect against multiple species of Clostridium. Furthermore, the recombinant toxin may be used as a safer alternative to the native toxins in vaccine manufacturing. This discovery stems from a collaboration between the laboratories of Dr. Borden Lacy of Vanderbilt University and Dr. Roman Melnyk of the Hospital for Sick Children.