The single-celled organisms that live in your body are called microbiota or microflora. They are mostly bacteria, but also include some fungi, viruses, and even protozoa.

Here are some specific terms:

* Gut microbiota: This refers to the trillions of microorganisms that live in your digestive tract.

* Skin microbiota: This refers to the microorganisms that live on your skin.

* Oral microbiota: This refers to the microorganisms that live in your mouth.

These microorganisms are important for your health in many ways, including:

* Digesting food

* Producing vitamins

* Protecting you from harmful bacteria

* Boosting your immune system

It's important to note that most of these microorganisms are beneficial and help keep you healthy. However, some can cause disease if they get out of balance.