Mamma's spit cleans everything

Hi everyone! Sorry for the late post – I’ve been busy getting things done in the lab all morning. Today’s post is another request. Anyone that knows everybody’s favorite hipster-bear knows one of his favorite sayings, “Mamma’s spit cleans everything”, but does it?

Let’s talk about spit.

Spit (saliva) is that lovely substance that keeps all of our pillows moist on drunken nights when you cannot help but drool. It is found in all humans and in most animals. In humans it is produced in the back of the mouth by some relatively large glands (salivary glands). Saliva is made up of a smorgasbord of ingredients. Obviously it is mostly made of water (98%). The other 2% consist of electrolytes (sodium, potassium, calcium, iodine, chloride, etc.), mucus and a lot of enzymes. Enzymes are proteins with a function – these are what allow your spit to do so many different things. You can also find around 8 million of your own human cells and around 500 million bacterial cells in every 1.0mL of spit. How gross is that?

So yeah, there are a lot of ingredients in saliva to allow it to perform all of the functions we need it to help with – it’s most obvious being digestion. In addition to helping soften food up, making it easier to chew and swallow, enzymes like amylase and lipase help jump start digestion. Amylase can break starch down into sugar (your body likes using the simple sugar) and lipase helps start breaking down fats. A good mouthful of slobber also helps wash food particles out of your teeth. Proline rich proteins found in saliva give saliva it’s lubricating and mouth moistening properties. So yay spit! But does it really clean everything?

A university study found that mouse saliva contains a protein (nerve growth factor – NGF). Mice with wounds treated with purified NGF had wounds that healed twice as fast as mice with wounds that were not treated. It is beneficial for mice to lick their wounds. Humans do not have NGF so stop licking yourself; you look like a damn fool. Human saliva is known to contain several antibacterial enzymes (ex. IgA, peroxidase, lactoferrin, lysosyme). These enzymes are found in saliva mainly to help keep the bacteria population in your mouth under control. It’s important to remember that a lot of bacteria live in the human mouth and it is not a bad thing they are there. The body does need to ward off some as a way of protecting your teeth and tongue, but the antibacterial enzymes in your mouth are not in high enough concentrations to be good cleaning products. So spit alone will probably not clean everything…

…although, it may not hurt. As long as you can be sure you are not introducing new problems by spitting (read: don’t spit on something to clean it if you have herpes), spit can wipe away large particles, like dirt, just like washing under water would. I would still recommend using clean water though.

Now go out and enjoy the 25,000 quarts of spit you are going to produce in your life. Need a visual? That is enough to fill an Olympic size swimming pool.