Macrophages love frosting.

Well, they do. Macrophages are the cells of your body that go around eating everything. You're now the privileged viewers of page 7 of my immunology lecture notes.
The yellow box is filled with lungs, pointing to surfactins. That's the goo that keeps your lungs from being stuck shut when you breath out. Apparently the goo also decorates  bacteria in green globules of frosting.

Macrophages love frosting. They'd eat birthday cake on the ground, they like frosting so much. (Really, let's look within and see who among us wouldn't eat birthday cake, even off the ground. Birthday cake is delicious, and there's the 5 second rule that has nothing to do with what microbes are doing to your food and everything to do with how much you want that piece of floor-covered deliciousness.)

Don't worry, though. That cake-bacteria would have to go through 5 physical barriers and avoid 3 different sets of ubiquitous proteins, all of whom want to poke holes in bacteria, to make you feel sick. If you're allergic to cake, though, Helper T-cell 3 would pretty much set off all the stuff that makes you feel bad to get rid of all particles of the cake.
And that's the very, very general overview of what I learned in immunology today.
I love school.