Polonelli proposes that the bacteria could be used to deliver and produce vaccine antigens directly on the mucosal surface. Whereas Polonelli's team decided to work with a bacterium that is already a thriving member of the body's bacterial community, Lothar Steidler of Ghent University and Flanders Interuniversity Institute for Biotechnology, in Gent, Belgium, and colleagues modified a common bacterium used in food fermentation. The cytokine interleukin-10, which reduces inflammation, has been approved for treating IBD, but is difficult and expensive to produce. But this is not the case with Lactococcus lactis . Currently, the usefulness of IL-10 is limited because systemic delivery of the protein causes a suppression of the entire immune system.
Local delivery requires injections and enemas.
The intestinal inflammation can cause diarrhea, abdominal cramps, weight loss, and nausea and can recur throughout life. In severe cases, malnutrition and dehydration due to poor absorption of nutrients in the gut, can lead to death. The drug-producing bacteria were added to a watery slurry and fed to the mice. Mice lacking both copies of the IL-10 gene are genetically prone to developing colitis by the time they are eight weeks old. The mice had slight inflammation of the intestinal lining, but were not significantly different from healthy mice.