Published 5th January 2022

How are gut health and anxiety connected?

The physical symptoms of anxiety vary, but many of the more common ones — like a churning stomach, diarrhea, or feeling sick — relate to your gut. Scientists have found that improvements in gut health can help with anxiety symptoms. 

Anxiety stems from worries about a potentially threatening situation, whether that trigger is real or imagined. And it’s something that we feel in our bodies as well as our minds. 

Your gut and your brain are directly linked and can communicate in a number of ways, so experiencing anxious thoughts can affect your gut, too. 

Through this gut-brain connection, gut health can also have an effect on anxiety, and a key player in this is the gut microbiome. 

Your gut microbiome is the collection of bacteria and other microbes that live in your gut. It’s unique to you and important for your health. 

At ZOE, we run the largest study of the gut microbiome and nutrition in the world. The ZOE program can help you understand the makeup of your individual gut microbiome by telling you which of the 15 “good” and 15 “bad” gut microbes that we’ve identified live in your gut.

To find out how ZOE can help improve your gut health, take our free quiz.

In this article, you can read more about the connection between gut health and anxiety, the treatment options for the condition, and how you can improve your gut health through your diet. 

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How are your gut and your brain connected?

Your brain and central nervous system control much of your body. But your gut also has its own “brain,” called the enteric nervous system (ENS).

The ENS is the largest collection of nerve cells outside the brain. It’s physically connected to your brain and can communicate with it. 

The communication between your brain and your ENS is a two-way street — what happens in your brain can affect your gut, and what happens in your gut can affect your brain. Your gut microbiome plays an important role in many of these communications. 

Scientists studying rats and mice have found that bacteria in their gut can influence the development of areas in the brain related to pain, stress, and emotional behavior. In turn, signals from the brain can alter the composition of the gut microbiome. 

Although more research is needed to understand how this works in people, there are three main ways that your gut microbiome influences communication between your gut and your brain: 

  1. The gut contains two-thirds of the body’s immune cells. These fight microbes that cause disease but allow your gut bacteria to send signals to the brain without attacking them.

  2. Your gut is connected directly to your brain by the vagus nerve. Through this route, substances produced by your gut microbiome can affect brain functions. 

  3. The enteric nervous system releases and responds to hormones and neurotransmitters, like serotonin, that affect brain function and mood. Changes to your microbiome can influence the production of these chemical messengers. 

What are the symptoms of anxiety?

Over a third of the population have experienced anxiety at some point in their life. More recent surveys suggest that this number has gone up during the COVID-19 pandemic. 

There are different types and degrees of anxiety, and feeling anxious doesn’t necessarily mean you have an anxiety disorder. 

Anxiety disorders tend to involve more severe, longer-term, or recurring symptoms, and some types can be very debilitating. People with generalized anxiety disorder (GAD) can worry a lot about everyday things and may feel “on edge” a lot of the time. 

People with social anxiety disorder have an intense fear of being judged by others and will often do anything to avoid work or social situations that bring up these feelings. 

Anxiety activates your stress response — also known as your “fight, flight, or freeze” response. This can cause a variety of physical symptoms that may be sudden and short-lived or longer term, depending on the situation and the person. 

Some of the most common symptoms of anxiety include: 

  • feeling hotter or colder

  • pounding heart

  • faster breathing

  • churning stomach

  • feeling sick

  • sleeping difficulties

  • difficulty thinking clearly or with memory

  • changes in sex drive

  • headaches or muscle soreness

How does gut health affect anxiety?

As many people who have experienced anxiety will know, it’s often linked with gut issues like feeling sick, a sensitive stomach, and constipation or diarrhea — or with ongoing conditions like irritable bowel syndrome (IBS).

Researchers have found that worse IBS symptoms can be associated with more severe anxiety

Scientists have also looked at the link between our gut microbiomes and anxiety using a process called fecal microbiota transplant (FMT). FMT takes samples of poop containing one person’s microbiome and transplants them into another person’s gut. 

In several different studies, researchers transplanted poop containing microbes from the guts of people who did not have anxiety into those with anxiety. 

In all of the studies, the symptoms of the people who received the samples were significantly reduced, although this usually only lasted for a few months. The same happened the other way around. When poop containing microbes from the guts of people with anxiety was transplanted into those without anxiety, it increased their levels of anxiety.

One way to improve the health of your microbiome is by eating foods that your “good” gut microbes like and cutting down on foods that promote “bad” microbes. We’ll look at this in more detail in the section below. 

Ways to manage anxiety

If your anxiety continues for a long time or is causing you distress, you should see a doctor. Depending on the type of anxiety you have and how severe it is, they may prescribe medication.

They may also suggest different methods to help you manage your anxiety yourself.

Counseling and cognitive behavioral therapy

Talking therapies like counseling and cognitive behavioral therapy (CBT) can help with a range of psychological and physiological conditions. Studies show that they are effective with many different types of anxiety and can improve overall quality of life for people with anxiety disorders. 

Through these sessions, you learn how to identify the things that trigger your anxiety and how to change your thought and behavior patterns around them. 

Medication

There are several types of medication that a doctor can prescribe for anxiety. Treatment usually starts with selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs).

Other options include benzodiazepines. It’s important to work with a doctor to find the best type of medication and dose for you. 

Breathing exercises, mindfulness, and meditation

When your body is in a heightened state of anxiety, you may experience shallow breathing, an increased heart rate, dizziness, and difficulty concentrating. 

Practicing deep breathing can soothe that stress response and help you to focus, which can lead to better outcomes. 

Mindfulness and meditation, which use breathing and other techniques to help ground you in the present, can help redirect turbulent thoughts and reduce anxiety symptoms in both the long and short term. 

Exercise

Physical activity is good for your brain, your gut, and the connection between them. Exercise redirects your focus away from stressful situations and improves concentration and your ability to stick to healthy behaviors. 

Exercise affects different parts of your brain that can reduce stress related responses. It also stimulates your brain to produce chemicals like dopamine and serotonin that help tackle anxiety. 

Even short-term, moderate cardiovascular exercise has been linked to significantly reduced anxiety symptoms, but increasing your levels of exercise further can be even more effective. 

Diet

Improving your diet can help boost your gut health and may be able to help with anxiety. 

Researchers have found that high quality diets — including those containing more fiber,  omega-3, and “good” bacteria called probiotics — may be linked to a lower risk of anxiety, stress, and depression symptoms. 

Omega-3s are a type of polyunsaturated fatty acid. They are essential micronutrients that can’t be made by your body, so you need to get them from food. 

There are different types of omega-3 — those found in oily fish like salmon, mackerel, and herring, and another type found in nuts and seeds like flax seeds, chia seeds, and walnuts. 

Some studies suggest that the types of omega-3 found in oily fish may help to reduce anxiety symptoms, but others found that they have limited or no effect. More research is needed to establish how strong the links between omega-3s and anxiety are.

Probiotics

Probiotics are live microbes that scientists believe may provide health benefits. One way to get probiotics is in the form of supplements. There is some evidence that they may help with symptoms of anxiety, but more good quality research is needed.

Scientists looking at 21 different studies found that when people with anxiety changed their diet, they experienced improvements to their gut microbiome and fewer anxiety symptoms.

But while some probiotic treatments were associated with improvements in anxiety, non-probiotic approaches showed better results. 

Other research into the use of probiotic supplements to treat anxiety has also been inconclusive.

Part of the reason that probiotic supplements are less effective than you might expect could be down to the types of bacteria they contain.

Most supplements use the microbes that are the easiest to grow, not necessarily those that are best for improving your gut microbiome. To get probiotic microbes to take up residence in your gut, it’s also important to take them regularly.

Probiotics exist naturally in many fermented foods, including live yogurt, sauerkraut, aged cheddar, and other unpasteurized cheeses, kimchi, and miso. 

At ZOE, we recommend eating a small amount of fermented food containing probiotics every day. 

Scientists studying over 700 people who were prone to anxiety found that eating fermented foods containing probiotics was linked to reduced symptoms of social anxiety

Whether or not you’re consuming probiotics, it’s important to feed your good gut bacteria if you want a diverse and healthy microbiome.

That’s one of the reasons that getting plenty of fiber in your diet is so important. Fiber contains substances called prebiotics that your gut bacteria thrive on. 

You can get prebiotics from a wide range of plants, including onions, leeks, garlic, asparagus, Jerusalem artichokes, legumes like chickpeas and lentils, and whole grains like barley, oats, and rye.

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Understanding your individual gut health

While there are broad guidelines you can follow that are likely to help improve your gut health — like limiting ultra-processed foods, eating a wide range of plants, and trying fermented foods — ZOE has shown that everyone’s gut microbiome and the way our bodies respond to foods are different. 

A ZOE test can tell you which of the “good” and “bad” gut microbes that we’ve identified live in your gut. It can also tell you which foods are your personal “gut boosters” that will support the growth of good bacteria and which are your “gut suppressors” that promote “bad” bacteria.

The ZOE program can help you to eat more of the right foods for your body, to improve your gut health and overall health.

Find out more about what ZOE can do for you.

Summary

Your gut and your brain are directly connected and can communicate with each other in a number of ways. 

Your gut microbiome — the collection of bacteria and other microbes that live in your gut — can influence the messages your gut and brain send to one another. 

There is good evidence that changing your gut microbiome can have an effect on anxiety. Scientists have shown that transplanting gut microbes from people without anxiety into those with anxiety can help reduce the recipients’ symptoms in the short term.

The same is true the other way around. Giving people without anxiety samples of gut bacteria from people with anxiety can lead to anxiety symptoms.

If you have continuing anxiety or it is causing you distress, you should talk to your doctor. They may prescribe medication or suggest other ways to help you manage your symptoms, like counseling, breathing exercises, mindfulness, or exercise.

One way to improve your gut health, which may also help with anxiety symptoms, is by changing your diet. There are strong links between a higher quality diet containing more plants and fiber and reduced anxiety symptoms. 

For a personalized approach to improving your gut and overall health, ZOE’s at-home test can tell you which “good” and “bad” bugs live in your gut, identify your “gut booster” and “gut suppressor” foods, and help you find the best foods for your body.

Take our free quiz to find out more.

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