Have you ever gotten sick with some bacterial gut infection and lost your appetite? Well this is a natural response, because when your inflammasome (which is responsible for the innate immune response to common bacterial traits such as flagella) is activated, it activates an enzyme called IL-1B, a cytokinase, which both facilitates inflammation and interacts with the vagus nerve, which connects your gut and your brain through the central nervous system. When the vagus nerve is stimulated by IL-1B, you lose your appetite and starve out the invading bacteria. Brilliant, right?
Wrong. The bacteria are tricky. Salmonella Typhimurium (also known as typhoid fever) has developed an enzyme called Salmonella Leucine Rich Repeat Protein (SlrP) which inhibits the activation of IL-1B, which inhibits your ability to mount an anorexic response. This means that the bacteria not only continues to be nourished by your natural bodily functions, but it is more capable of spreading than before.
This is particularly bad for mice, because S. Typhimurium spreads via fecal matter, and mice eat one another's poop. There's a happy thought for your memorial day weekend!
If you want all of the fascinating details, check our this article. It's not a tough read and I thought it was quite exciting!