It's fairly common for people to drastically underestimate the importance of their saliva. Though it is mostly made of water, it also contains certain minerals, enzymes, antimicrobial agents, and proteins, and it plays an enormously important role in your oral health.
Among other things, that means keeping the following three nasties from building up in your mouth.
1. Bacteria
Your mouth is never going to be completely free from bacteria. That sounds bad, but the truth is that the body is well-equipped to deal with a small amount of bacteria – it's when some of its natural defences are compromised that bacteria becomes more problematic. Such is the case with saliva.
Saliva carries antimicrobial agents that help kill bacteria, thus maintaining your oral health. At nearly all times, your teeth are protected by a thin layer of saliva for just that reason. If there isn't enough saliva in your mouth, bacteria can multiple more easily. That's bad for your teeth and gums, and it can also lead to the development of sores.
2. Thrush
Thrush is something you might associate with more intimate parts of the body than the mouth, but it can develop here too. Thrush is caused by candida fungus, a type of yeast. Again, there will always be some candida fungus in your mouth, but it is kept in check by saliva. If this isn't happening, you may develop oral thrush.
Symptoms normally include raised white areas and pain while chewing or swallowing. That's bad enough, especially since oral thrush can be quite embarrassing, but the condition can become even more serious if the infection is able to spread to the oesophagus. Left unchecked, it can reach other parts of the body, including the heart and lungs.
3. Dead Cells
You should already know that saliva helps wash away any nuggets of food left caught between your teeth, but it also gets rid of your dead cells. This isn't something that people often think about, but the gums, tongue, checks, and roof of the mouth all need to get rid of dead cells.
The saliva is responsible for cleaning those dead cells away; as well as washing them off the surfaces inside your mouth, its digestive enzymes help break them down. Without a healthy flow of saliva, those cells will start to decompose inside the mouth. This encourages the further growth of bacteria, and it generally causes very unpleasant breath.