WEST LAFAYETTE, Ind.—Purdue researchers have discovered that the same Listeria protein that allows the bacteria to pass through intestinal cells and into bloodstreams can help block those same paths when added to a probiotic, according to a new study published in the journal PLoS One. The findings may lead to the development of a pill or probiotic drink that could be given to at-risk patients to minimize the risk of Listeria infection.
The researchers earlier work showed that Listeria triggers intestinal cells to express heat shock protein 60 on their surfaces. That allows Listeria to bind to the intestinal cells using an adhesion protein and pass into them, acting as a sort of gateway to the bloodstream. The researchers found that probiotics alone were ineffective in combating Listeria. They added the Listeria adhesion protein to the probiotic Lactobacillus paracasei and were able to decrease the number of Listeria cells that passed through intestinal cells by 46%. With the adhesion protein, Lactobacillus paracasei interacts with heat shock protein on the surface of intestinal cells just as Listeria would. The probiotic then attached to the intestinal cells, crowding out Listeria.