Why Don't Cuts And Wounds Inside The Mouth Get Infected By Bacteria?

A significant fraction of bacteria that actually inhabit our oral cavity are ‘friendly’ bacteria. saliva plays a crucial role in ensuring that the nasty bacteria present in the mouth don’t make the wound any worse. That’s why wounds and cuts inside the mouth so rarely get infected by bacteria.

When you injure yourself or sustain a minor cut or bruise on your body, it usually heals itself in a week or two (depending on the nature and severity of the wound). In general, cuts and scrapes on most parts of the body take around the same amount of time to heal.

However, you may have also noticed that if you get a cut inside your mouth, it tends to heal faster than other body parts. That seems strange, doesn’t it? First of all, the fact that mouth cuts and bruises heal faster is quite intriguing to begin with, but what makes it even more interesting is that the mouth is filled with bacteria (certain microorganisms practically live inside the mouth).

Dentist making anaesthetic injection to woman patient tooth teeth

The oral cavity is filled with a huge number of bacteria. (Photo Credit : Nejron Photo / Shutterstock)

From a purely logical standpoint, someone with no knowledge of the environment that exists within the oral cavity would not be wrong to assume that mouth injuries should take more time than usual to heal, rather than less.

However, in reality, that simply isn’t the case. Mouth injuries typically heal faster, but do you know the reason behind this?

The Environment of the Mouth

For the uninitiated, it might come as a surprise that the mouth is actually home to entire communities of microorganisms that exist for as long as you are alive! Of course, it’s not the same set of bacteria that live there throughout your life; when they die, their descendants take their place within your oral cavity, followed by their descendants after them and so on.

The millions upon billions of bacteria that live in your oral cavity undoubtedly affect the health of your teeth, gums and your overall dental hygiene. However, not all of those bacteria are harmful. In fact, most of these oral microorganisms are harmless, or even helpful!

There are more than 700 different strains of bacteria in the human mouth, but most humans don’t host more than 35-70 varieties of these bacteria. There are certain microorganisms, called probiotics, which are also beneficial forms of bacteria that help in the process of digestion.

So, it’s clearly well established that the human mouth is home to a lot of bacteria. Now, let’s deal with the main question:

Why don’t bacteria make cuts and bruises worse?

First off, as mentioned earlier, a significant fraction of bacteria that actually inhabit our oral cavity are ‘friendly’ bacteria. We share common interests with them, providing them with optimum temperature conditions, humidity and nutrients to live, while they safeguard us from the infections caused by other bacteria living within our mouth. It is important to note that this dynamic of ‘mutual help’ is maintained only when the host individual is healthy.

Saliva plays a major role in maintaining good dental health.

In addition, it’s very important to note that our saliva also accelerates the healing process. You see, saliva creates a humid environment within the oral cavity, which improves and enhances the functioning of inflammatory cells that are critical for the healing of wounds.

Saliva to the rescue!

Saliva plays host to many different proteins that play an instrumental role in various stages of intra-oral wound healing. Members of the salivary histatin (antimicrobial proteins found in saliva) family help in wound closure in vitro by increasing cell migration and cell spreading. There are even components in the saliva that destroy bacterial cell walls. Furthermore, tissue factor present in salivary exosomes accelerates blood clotting.

Saliva plays host to many proteins that play an instrumental role in various stages of intra-oral wound healing. (Photo Credit: Pereru/Wikimedia Commons)

In a nutshell, suffice to say that saliva plays a crucial role in ensuring that the nasty bacteria present in the mouth don’t make the wound any worse. That’s why wounds and cuts inside the mouth so rarely get infected by bacteria. However, this is only true for healthy individuals. More specifically, if a subject is suffering from some affliction, to begin with, then the relation between the mouth bacteria and the body is severely affected; as a result, cuts and injuries within the mouth might not heal as swiftly as they usually do.