It’s an oft-cited strange-but-true fact: There are as many bacteria in your gut as there are other cells in your body. This community of microbes (not just bacteria, but viruses, fungi, archaea, and eukaryotes as well) is called the “gut microbiome,” and it plays an important role in your health.
That our bodies are awash in other critters is not a new discovery. In the 17th Century, Anthony van Leeuwenhoek, an amateur lens grinder from Delft, Holland, built a microscope (he did not invent it, just improved it) and began using the device to look at pretty much anything he could find: fingernail clippings, gunk from the teeth of a man who never brushed, even his own feces.
When he described what he found to members of the Royal Society, he commented that the samples seemed to be alive. The wiggling creatures he saw through his microscope he called “animalcules.” We call them microorganisms. Since then, scientists with much better equipment have discovered that approximately 100 trillion microorganisms, including more than 3,000 species of bacteria, live in the human gastrointestinal tract. One hundred trillion is more than the estimated number of stars in the Milky Way.
Benefits of Microorganisms in the Gut
When you contemplate all the critters that live in your gut, it’s easy to think of them as just being along for the ride. But that’s not quite right, according to Beth McCormick, founding director of the Program in Microbiome Dynamics and Center for Microbiome Research at the University of Massachusetts. “They’re not passengers,” she says. “They’re partners.” We couldn’t live without them.
Our tiny partners help digest food by breaking down carbohydrates that we can’t process ourselves. They synthesize vitamins, such as vitamin K and many of the B vitamins. Some of the members of this community destroy potentially harmful bacteria. They also help regulate the immune system.
“The gut is home to the largest population of immune cells in the body,” McCormick says.
Read More: Our Gut Microbiome Turns Sugar into Compounds Vital for Our Health
An Ecosystem of Microbes
This vast array of microbes is best thought of as an ecosystem, something like a coral reef or a rainforest, says McCormick. As in any ecosystem, the different members of the community all affect each other, and as in any ecosystem, things can go very wrong if it gets out of balance, a state called dysbiosis. The gut microbiome is out of balance when there are too few beneficial bacteria, too many potentially harmful ones, or simply not enough diversity in the community.
An out-of-balance gut microbiome has been linked to many conditions, from inflammatory bowel disease and obesity to neurologic disorders. That’s right — it’s not just digestive problems.
Biochemical signals go back and forth between the gut and the brain. Researchers refer to this connection as the gut-brain axis. McCormick explains that microbes in our intestines produce neurotransmitter-like compounds that can modulate inflammation, which can affect brain function and mental health. There’s still a lot to learn about how the gut-brain connection works, but it’s turning out to be one of the most exciting areas of microbiome research, she says.
How Do We Take Care of Our Microbiomes?
So with all this at stake, how do we make sure our microbiomes stay healthy? One key strategy is to feed the good microbes and not the bad ones. Foods that feed the good guys are called prebiotics. Good choices are whole grains, such as whole oats, fruits like blueberries and bananas, and vegetables such as asparagus, spinach, onions, and garlic.
But it’s not just food. McCormick points out that caring for your microbiome means getting enough sleep, exercising, and keeping stress under control. Some drugs, particularly antibiotics, can wreck the gut microbiome fast. The good news is that with time, your inner ecosystem can come back into balance after a normal course of antibiotics. It’s long-term use that can cause serious problems.
What McCormick doesn’t recommend are probiotic supplements from the grocery store, pharmacy, or online retailers. There’s little solid evidence behind oft-made claims that these supplements support gut health, boost immunity, and improve mood, she says.
So when you make lifestyle choices, be sure to think of what’s best for the little partners in your gut.
This article is not offering medical advice and should be used for informational purposes only
Read More: It Doesn't Take Long to Reset Your Gut Health With Small Lifestyle Changes
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
The Royal Society. Antoni van Leeuwenhoek
NASA. Star Basics
Avery Hurt is a freelance science journalist. In addition to writing for Discover, she writes regularly for a variety of outlets, both print and online, including National Geographic, Science News Explores, Medscape, and WebMD. She’s the author of Bullet With Your Name on It: What You Will Probably Die From and What You Can Do About It, Clerisy Press 2007, as well as several books for young readers. Avery got her start in journalism while attending university, writing for the school newspaper and editing the student non-fiction magazine. Though she writes about all areas of science, she is particularly interested in neuroscience, the science of consciousness, and AI–interests she developed while earning a degree in philosophy.
