What is biofilm?

A biofilm is like a tiny city made by germs that stick together on a surface.

Imagine you’re playing with your favorite building blocks, some red, some blue, some green. You stack them one after another until they form a big tower. That’s kind of what germs do when they make a biofilm. They stick to something like your toothbrush or the inside of a water pipe, and then more germs join in, layer by layer, creating a thick, sticky city.

Germs in a biofilm are like a team working together. Some germs attach themselves first, they’re like the builders. Others come later to help make the city bigger and stronger. This teamwork makes it hard for things like soap or medicine to reach all the germs, which is why sometimes you get stubborn toothaches or icky water from the tap.

Biofilms are everywhere! They can be on your teeth (that’s why you need to brush), inside a swimming pool, or even in hospital equipment. Sometimes they’re good, like when they help clean up pollution, but other times they cause trouble, like when they make infections harder to treat.

So next time you brush your teeth, remember: you're fighting off a tiny city of germs!