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Coral reefs, rainforests, wetlands – these are just a few examples of ecosystems. But you don’t have to go travelling far and wide to find them. You have your own personal ecosystem that goes wherever you go: your microbiome.

Your microbiome consists of a range of microbes that live in your body. Most of the microbes are bacteria, although it also includes other organisms, including fungi and bacteria-like organisms called archaea. There are a lot of these microbes inside you too: while the human body contains around 10 trillion human cells, the number of microbial cells is estimated to be about 10 times greater!

Most of the human microbiome is found in the intestines, although you can find microbes living in other places, such as in your mouth and on your skin. The fact that most of the microbes are found in the gut means you may also hear them referred to as gut flora. When you were born, you didn’t have a microbiome. Your gut would have been colonised by microbes pretty much as soon you entered the world. These microbes would have come from the environment and people around you.

It turns out that these microscopic buddies are pretty useful to their human hosts. They have been shown to help in the digestion of food, providing energy that would otherwise be unavailable. They also help produce some vitamins, and are also able to help keep harmful bacteria from growing out of control and making you sick.

Scientists are still learning a lot about the human microbiome and what it does. For one thing, most of the microbes are very hard to grow outside of the human body, meaning identifying individual microbe species is difficult. Advances in DNA technology now means that other identification techniques are possible, but there’s still a long way to go.

Your microbiome could have an even larger impact on health than first thought. Recent evidence suggests that the microbes in your body can affect things such as allergies, obesity and even mental health. You may not notice them, but it’s nice to know that every day you have a few trillion tiny friends looking out for you!

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