What is the Purpose of Saliva?

Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon
Saliva makes it easier to chew and swallow food.
Saliva makes it easier to chew and swallow food.

Saliva has a number of purposes that make it an extremely useful substance, making it sorely missed when people experience a reduced output. In addition to playing a role in the digestive process, it is also very important for oral health. Some animals have developed additional uses for it. Swifts, for example, have particularly gummy saliva that they used to glue their nests together.

Saliva helps keel levels of oral bacteria at a manageable level.
Saliva helps keel levels of oral bacteria at a manageable level.

One of saliva's most important roles is as a lubricator. It keeps the mucus membranes of the mouth moist, making them less subject to cracking and discomfort. This fluid also lubricates food in the mouth, making it easier to chew and swallow. As anyone who has experienced dry mouth knows, a mouth without saliva in it can start to feel extremely uncomfortable very quickly, especially when trying to eat.

Swifts use saliva to glue their nests together.
Swifts use saliva to glue their nests together.

Saliva also contains several enzymes that perform various functions. The enzyme lysozyme is antibacterial, so it helps to keep levels of oral bacteria at a manageable level. Digestive enzymes like amylase are also present, breaking food down before it reaches the stomach to make it easier to digest. When the enzyme balance is disrupted, it can cause health problems, most commonly in the form of a flourishing of bacteria in the mouth.

Saliva performs several important functions as a lubricant, antibacterial fluid and digestive aid.
Saliva performs several important functions as a lubricant, antibacterial fluid and digestive aid.

This substance also has a number of minerals that are regularly deposited on the teeth, helping to keep them healthy and to insulate them from bacteria in the mouth. In some cases, mineral deposits may build up too much, in which case they are known as plaque. The digestive enzymes in saliva also work to dissolve particles of food caught between the teeth, ensuring that they do not rot and compromise oral health.

Although saliva is highly beneficial, it is best kept in the mouth. While it does have some antibacterial properties, it should not be used like an antibacterial agent, contrary to popular belief, because the mouth is inherently not sterile. Applying it to a wound could lead to the introduction of oral bacteria to the bloodstream, and this is not desired. Saliva can also harbor some viruses, which is one of the reasons people are encouraged to avoid kissing sick people.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a TheHealthBoard researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a TheHealthBoard researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Discussion Comments

anon332692

My friend always thinks it is funny that I apparently have a 'phobia' of other people's saliva and she likes to spit on me because it freaks me out and when she does it I am always like do you know how much bacteria are in your saliva? She just laughs at me.

Charlie89

I am totally with @pleats -- saliva has always been one of my secret phobias. I know it's really strange, especially since I have saliva and wouldn't do without it, but something about other people's saliva (or even my own if I happen to spit it out for some reason) really, really gets to me.

That's why I could never be one of those people who gives the saliva drug tests -- I would be so grossed out by the idea of touching so many other people's fluids that I don't think I could even do the test.

It truly is amazing how clean humans think they are, when in fact, we're pretty much walking germ factories. So brush your teeth people, and don't spit...especially near me!

FirstViolin

I read a really interesting article recently about the connection between saliva and heart disease. Apparently brushing your teeth and flossing keeps the bacteria in your mouth at reasonable levels, which is of course excellent for hygiene, but also very important because some bacteria that can damage your heart can actually originate in the mouth!

I am not up on the in-depth science of it all, but apparently researchers found that those who brush their teeth more often have a lesser incidence of heart disease, so they started poking around and finally found out the bacterial connection.

Just gives you one more reason to brush and floss, right?

pleats

I'll be the first one to admit that saliva is interesting, especially after reading all these cool things about it, but to be honest, saliva always freaks me out a little bit.

It's necessary and lovely and I hate having a dry mouth as much as the next person, but seriously, when you think about all the germs floating around in the average person's saliva it is truly gross.

That's why I always hate it when people spit -- not only does it look really tacky, it's just unsanitary! Seriously, if you ever get the chance, look at some of the documentation about the massive amounts of bacteria in saliva. My bet is you'll be just as grossed out as I am.

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    • Saliva makes it easier to chew and swallow food.
      By: Glamy
      Saliva makes it easier to chew and swallow food.
    • Saliva helps keel levels of oral bacteria at a manageable level.
      By: japolia
      Saliva helps keel levels of oral bacteria at a manageable level.
    • Swifts use saliva to glue their nests together.
      By: avs_lt
      Swifts use saliva to glue their nests together.
    • Saliva performs several important functions as a lubricant, antibacterial fluid and digestive aid.
      By: Adrian Costea
      Saliva performs several important functions as a lubricant, antibacterial fluid and digestive aid.