Boogery-spit is beneficial for small bits of bleeding
There are things in this world that are hard to share with your children. Not because they will scare them, or expose some dark truth that you wish you could protect them from. Some things are hard to share because they go against everything you want to believe as a parent, even though they’re true. And gross. And… just… well, first graders will love it, anyway.
While it’s still a good idea to wash a cut to avoid infection, it turns out that washing it with spit might not be a bad idea. It’s not thanks to digestive enzymes in saliva being especially good at sealing a wound or anything, but because your saliva carries white blood cells, the front line of your body’s immune system (well, maybe after skin.) The white blood cells, called neutrophils in this case, have a variety of ways to fight potentially harmful bacteria, engulfing, disintegrating or even capturing it with sticky protein nets. This is true of all white blood cells, but it turns out the white blood cells in your spit are especially adept little cowboys, er, batericaboys.
Superior in slobber
The expectation would be that the digestive enzymes in your spit that are present to help break up your food would also break apart the white blood cells’ protein lassos. Instead, spit-covered wounds were found to have multitudes of these little immune nets in action, actually surpassing what you’d find without the addition of saliva. There are a number of major ingredients in your saliva, including water, salt, dead cells and mucus, and of course the secret, immune-boosting ingredient turned out to be the boogers.
Better with boogers
The mucus not only makes your spit stringy and stretchy, but it also helped protect the bacteria-catching protein nets from the digestive enzymes. The nets were stronger and protected, which made them durable and possibly more effective at cleaning a wound in the skin. When the mucus wasn’t present in the saliva, it’s effectiveness against bacteria dropped considerably. This doesn’t mean you need to start hocking loogies on your next cut, because mucus from your sinuses are likely acting to collect potential pathogens already. Although if you want to maximize your mouth’s capabilities for first-aid, you should have more spit built up in the morning, as you don’t really swallow it at night while you sleep.
This discovery isn’t completely new, of course. Various mammals are known to lick wounds instinctively, and dog saliva has been found to fight bacteria like Escherichia coli and Streptococcus canis already. However, excessive licking can stop the skin from healing, resulting in lesions. Also, infected wounds can actually transmit pathogens back to the mouth, as parasites and even rabies can be passed this way. So maybe skip the licking and stick to spitting the next time you get a cut.
Source: How Spit Heals Wounds by Rachel E. Gross, Slate