What’s The Difference Between Microbiome And Microbiota?

What’s The Difference Between Microbiome And Microbiota?

This simple guide will get you right up to speed with the small and subtle differences between microbiota and microbiome.

So, you’re feeling inquisitive and you perform a quick internet search. You type definition of microbiome or define microbiota – the words are different but the results are pretty similar. Well, let us explain.

Table of contents

What is a biome?

Animals, plants, and even oceans and soils have their own individual biomes made up of specific inhabitants.

Our bodies are not just ours, they are home to a vast collection of microorganisms. Ask most people to define microbiome, and a handful might say that it refers to a bacterial ecosystem that lives in a specific place. They may even mention the gut.

For scientists, a biome is an ecosystem made up of flora and fauna. They use the word micro to indicate that this ecosystem is invisible to the human eye. It is made up of mostly bacteria, but also viruses, archaea, and fungi, which all play a role in maintaining the environment's stability.

The microbiome explained. Video by the Microbiology Society

The human microbiome encompasses trillions of microbes that can be separated into subsections dependent on their location. When we say gut microbiome, we mean the microorganisms (and their genes) that reside in your colon.

But the microbiome isn’t just a feature of human beings - animals, plants, soils, and oceans have their own ones too. And no matter how you look at it, the gut microbiome plays a major role in human health.

Home to trillions of microbial cells, it is an essential part of our biology that supports many physiological functions, helps maintain the integrity of our gut lining, and protects us from disease and illness.

Microbiome vs microbiota

Although the terms are used interchangeably, there is a slight difference between microbiome and microbiota.

In many contexts, like on this blog, microbiota and microbiome are often synonymous, but you could be forgiven for thinking they are separate entities. It's better to think of them as overlapping definitions instead.

Basically, there are some small but relevant differences for researchers, as Miguel Toribio-Mateas, a nutritionist and clinical neuroscientist, explains: “Although they’re often used interchangeably, microbiota is the actual bugs and microbiome is the bugs AND their genes.”

In contrast, your gut microbiota describes the different microbe populations present in your large intestine, including bacteria, archaea, and viruses. It has evolved alongside humans to get to where we are today, living in a mutually beneficial relationship.

There are many types of bacteria present in the gut microbiota. However, although it was previously estimated that the body was home to 10 times more bacterial cells than human cells, it’s now believed that we have approximately the same number of both.

Microbiota vs microbiome

Microbiome Microbiota Metagenome
Microorganisms (and their genes) living in a specific environment Microorganisms (by type) living in a specific environment The genes of microorganisms in a specific environment
Refers to the bacteria (primary) and their genes (secondary) Refers to the taxonomy (name) of microorganisms present Refers to the collective functions of microbial genes

Some bacteria are beneficial because they provide an essential function for health, like the production of vitamins or butyrate. Others are deemed probiotic when they contribute several important functions, like Bifidobacterium and Lactobacillus.

We also have small amounts of opportunistic microbes, which have the ability to make us sick if they aren't controlled by the rest of our microbiota. And finally, there are many commensal microbes, which are harmless and live in harmony in the ecosystem.

Microbiome definition: it’s about the genes

The microbiome definition in biology refers to the microorganisms and their genes whereas the microbiota only refers to the microbes themselves. If you just want to talk about all the genes in an environment, it is called the metagenome - and it’s a common source of interest in scientific study too.

In other words, when we define microbiome, we’re referring to the microbes and their genetic material, and how they contribute to the health (or not) of the human body. Remember, pathogens will also make up some of your microbiome, not just the beneficial or commensal ones.

So what is microbiota?

The gut microbiota definition refers to the microorganisms found in a specific environment by type. This includes bacteria, fungi, viruses, protozoa, and archaea, and the diversity of the microbiota will vary from person to person.

Different bacteria have specific names determined by a branch of science called taxonomy, where biology experts are tasked with allocating a name and a rank in the tree of life.

For example, the probiotic L. rhamnosus is actually a species of Lactobacillus, a genus that belongs to the Firmicutes phylum, which is a member of the Kingdom of Bacteria (as opposed to that of plants or animals).

Different bacteria live on different parts of the body, prefer different foods, and perform different functions. There is an oral microbiota of the mouth, a microbiota of the skin that has many subcategories (the armpits, nose, feet, etc.), and a gut microbiota - among many others of course.

☝️FACT☝️ Microbiota plural is often microbiota, but if referencing different types or a collection, the term microbiotas may be used.

Why is the microbiome important?

The trillions of bacteria in your gut have a profound influence on our health, metabolism, and even disease protection.

When we hear the words microbe, bacteria, or virus, we tend to think of something bad, but not all of these microorganisms cause disease. In fact, we rely on them to perform the functions we may not be able to.

The bacteria in our gut help to breakdown the plant fibres we eat because our bodies don’t produce enough enzymes for this arduous task. By doing so, they turn carbohydrates into beneficial metabolites, like butyrate and vitamins.

A balanced microbiota with beneficial and probiotic bacteria performs many other functions, like maintaining the correct pH to deter pathogens and keeping the gut lining healthy. Research even shows that gut microbes are involved in maintaining a healthy body weight.

How does microbiome analysis work?

Explore your gut bacteria and their functions with microbiome test. It can give you real insight into the unique ecosystem of your gut.

The Atlas Microbiome Test uses advanced DNA sequencing technology to screen the genes of your gut microbes and determine what bacteria are inside you and what they're doing. Just order the test online, collect a tiny stool sample, and send it back. Here's what you can learn from it:

  • See how well your gut microbes protect you from disease
  • Find out how your diet is affecting your gut microbes
  • Discover your gut microbes ability to make vitamins
  • Get personalised food recommendations based on your results

Just remember this

Microbiota describes the actual bacteria, and microbiome is the bacteria AND their genes.

The terms microbiota and microbiome are used so interchangeably that it’s easy to think they mean exactly the same thing. While they are not exactly identical, you'll be fine if you use one or the other. We do on the blog too, and all of our articles are reviewed by microbiome experts.

So unless you’re conducting some very specific scientific research, you don’t need to beat yourself up about the tiny differences. Be it gut microbiome or gut microbiota, we are still referring to the trillions of microbial cells in your colon.

Atlas microbiome microbiota test
You really only need a tiny sample of poop for the Atlas Test

As for the definition of microbiomes, each microbiome refers to all the microorganisms and their genetic material that are found in an environment. Remember, microbiome and microbiota are not just in humans, there are microbiomes even on buildings, in the underground, and the ocean.

☝️FACT☝️The definition of microbiotic can be either the adjective of microbiota (a noun) or a confusion with the term “macrobiotic” used to describe a type of diet.

Leanne Edermaniger
Leanne Edermaniger Science writer who enjoys laughing which is scientifically proven to help you live longer.

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