Munching on bacteria could be a good way to stimulate your immune system: Biologist Simon Cutting of the Royal Holloway University of London has transformed bacterial spores into an edible vaccine. He and his collaborators genetically altered the common bacterium Bacillus subtilis so that it produced harmless fragments of the toxin produced by tetanus. Then his team starved the bacterium so that it turned into a spore—a desiccated packet tough enough to survive a trip through the digestive tract and into the bloodstream. Most of the mice that inhaled or ate the modified spores were then able to survive a lethal dose of tetanus.
Engineered bacterial spores could be eaten or inhaled as a vaccine.Photograph courtesy of Simon Cutting/Royal Holloway University of London