Microbiome vs microbiota

If you've ever tried to look up information about the microbiome, chances are you've been confronted with many confusing terms – microbiome, microbiota, and microorganisms, among others. But just as you have guessed, there is a difference between the definition of the microbiome and all the others.

What exactly is the difference between each of these terms, and which one should you use when discussing this fascinating research area? This article explores the differences between these terms and how they are used in scientific research. 

In the end, you will better understand the different terms used in microbiome research and why it is vital to use the proper term when discussing this field.

What is the difference between the definition of microbiome and microbiota?

The microbiome is used to describe the genomes of all microorganisms living in a particular environment. At the same time, a microbiota refers to all bacteria living in a particular environment. It is important to note that it only refers to the bacteria in a particular environment and not the fungi, viruses, and all other single-celled human body organisms.

In simple terms, the part of a microbiome, like the gut microbiome, that consists of only bacteria is called the microbiota. In contrast, the microbiome is a term to refer to the collection of all microbes, such as bacteria, fungi, and viruses, including their genetic material. 

On the internet and in general, the term microbiome is used more frequently than microbiota. But this is often used in the wrong manner. When we refer to the bacteria that make up the microbiome, we prefer to use the term microbiota! On the other hand, when we refer to all the organisms in a particular environment, we prefer to use the term microbiome.

If you're interested in finding out more about the various kinds of bacteria that make up the microbiota click here. 

What are microorganisms?

There is a lot of confusion surrounding the terms microbiome, microbiota, and microorganisms. Are they all the same thing? Is one more important than the other? Now that you know the difference between the definition of microbiome and microbiota, it is time to explain what microorganisms are!

Microorganisms are tiny living things that can only be seen with a microscope. Yet, they are found everywhere on Earth, including inside our bodies. Some microorganisms are helpful to us, while others can cause disease.

However, it is essential to note that not all microorganisms are pathogens; many are essential for human health. In fact, many are essential for our health and well-being. The human body is home to trillions of microbes, most of which live in our gut. These gut microbes play a vital role in digesting food, synthesizing vitamins and minerals, and protecting us from harmful bacteria. Most importantly, they keep our guts healthy!

Which term should I use when describing all of the (micro)organisms or bacteria in my gut?

The terms microbiome, microbiota, and microorganisms are all used to describe the collection of bacteria in your gut. However, there is no definitive answer for which term is best to use since each term has its definition and, therefore, may be more or less accurate depending on the context in which it is used.

For example, the term microbiome is often used to describe the entirety of microbial organisms living in a specific environment, such as the gut. However, the microbiota is more specifically used to refer to the bacterial communities that exist within that environment, while microorganisms encompass all types of microbes (including bacteria, viruses, and fungi).

There is a lot of information on the internet about the microbiome and microbiota, but the wrong term is often used. Researchers who dedicate their life to microbiome research will be happy to know that you now know that microbiota is the correct term to use when describing all of the bacteria in your gut!

The microbiota in numbers 

According to estimates, the gut microbiota contains 1014 (100,000,000,000,000) bacteria, or more than 1000 times the Earth's population. The DNA of all these cells collectively referred to as the microbiome, has 3 million unique genes. Compared to the approximately 23,000 genes included in the human genome, it is clear that bacteria can perform many more activities than our body's cells. 

Since their discovery, we've identified over 2000 unique bacteria, and we're constantly uncovering new ones. Each individual has between 400 and 600 unique species (estimates vary), which changes in response to the bacteria we consume and our genetic predisposition, among other variables. As a result, each person possesses around 30 different species of bacteria, which we refer to as the core microbiota.