Updated 23rd February 2022

Why gut health is important and how to improve it

Gut health isn’t just about comfortable digestion. Having a diverse range of beneficial bacteria in the gut supports your immune system and shapes your physical and mental health.

The trillions of bacteria, fungi, protozoa, and other microbes living in your digestive tracts make up your gut microbiome, and the composition of that microbiome is unique to you. 

We’ve all heard the phrase, “you are what you eat.” At ZOE, we don’t support the idea that guilt should inspire specific diets, but the basic concept is true. The food you eat affects the balance of bacteria in your gut.

You can’t change your DNA, but you can change your gut health. Lifestyle tweaks, especially around what you eat, can change your gut microbiome for the better and improve your overall health. 

In this article, you will learn about the best foods for gut health, lifestyle tips for improving gut bacteria, and how to spot the signs of an unhealthy gut.

8 foods for gut health

What makes a balanced diet varies in meaning between different people. When it comes to gut health, the idea of balance relates to the types of bacteria you have in your microbiome. 

A healthy gut contains a wide variety of bacteria. ZOE scientists and their colleagues, who run the largest nutritional study of its kind, recently identified 15 “good” gut bugs that are linked to good health. They also found 15 “bad” bugs that are indicators of poor health. 

Having more of the good bugs and fewer of the bad bugs is good for your gut and your health. 

To improve the health of your gut, prioritize foods that feed those “good” bugs and reduce the amount of “bad” bugs in your gut.

Aim for 30 different plant foods each week. Try to “eat the rainbow” by mixing and matching foods in different colors. These foods are high in fiber and polyphenols, which are a type of antioxidant that “good” gut microbes love.  

Our cutting-edge research makes it possible for the first time to take a test to find out which of the 15 good and bad bugs live in your gut, helping you find the best foods to improve your gut health. Take the free ZOE quiz to find out more. 

Here are the best foods for gut health:

1. Fruit and vegetables 

You don’t need to be vegetarian or vegan to have a healthy gut, but eating more plants helps you get enough fiber, which is the key fuel for your gut bugs. These foods also contain polyphenols, which may reduce “bad” microbes.

2. Nuts and seeds

Another good source of fiber and polyphenols, nuts and seeds also contain healthy fats that can improve cardiovascular health and how well your body responds to sugar. This is because combining nuts — which contain healthy fats — with carbohydrates can help prevent blood sugar spikes.

3. Prebiotic foods

Many fruits, vegetables, nuts, grains, and legumes also contain prebiotics, a specific type of fiber that fuels “good” gut bacteria.

4. Legumes

In addition to their high concentration of dietary fiber, legumes like chickpeas and lentils have a type of prebiotic fiber called galactooligosaccharide, which feeds “good” gut bacteria.

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5. Whole grains

These complex grains are a great source of fiber for your microbiome. They also contain many other important nutrients and may lower your risk of chronic conditions like heart disease.

6. Probiotic fermented foods

These foods have live bacteria in them and help to increase the diversity of your gut bacteria. They also increase the production of conjugated linoleic acid, an omega-6 fatty acid, which might lower your risk of chronic disease, such as type 2 diabetes

7. Coffee

Caffeine-lovers, rejoice — our research has found that people who drink coffee have a more diverse microbiome.

8. Unprocessed or minimally processed foods

Limit ultra-processed foods, which undergo industrial processing, as these have high levels of refined sugars, salt, and unhealthy fats. Our research found that people who eat a lot of highly processed foods are more likely to have more “bad” bugs in their gut. Opt for unprocessed or minimally processed foods instead. 

Your gut health menu

Fruits and vegetables

apples, oranges, raspberries, blueberries, strawberries, peaches, fresh cranberries, Brussels sprouts, spinach, kale, avocado, broccoli, zucchini

Nuts and seeds

almonds, walnuts, cashews, hazelnuts, pine nuts, pistachios, chia seeds, pumpkin seeds, hemp seeds, sunflower seeds, sesame seeds


lentils, chickpeas, peas, black beans, kidney beans, pinto beans, soy beans

Whole grains

oats, bulgur, quinoa, buckwheat, spelt

Prebiotic foods

onions, garlic, cabbage, leeks, pearl barley, flaxseed, nectarines, blueberries, grapefruit, artichokes, cocoa

Probiotic fermented foods

live yogurt, kefir, sauerkraut, kimchi, miso, aged cheddar, parmesan, swiss cheeses

Other ways to improve gut health

Your diet isn’t the only gateway to better gut health. You can also tip the balance of your microbiome in favor of “good” bugs through research-backed lifestyle changes.  

Get more sleep

We know the microbiome can influence sleep and vice versa. Most research so far, however, has been conducted in mice. 

One study suggests sleep disruptions can change what bugs are present in the gut. Mice that experienced 4 weeks of poor sleep increased their food intake and developed low levels of inflammation in their fat tissue. Additionally, they had worse blood sugar control.

Research by ZOE scientists also found that sleep affects how our bodies respond to food the next morning. Going to sleep earlier helps prevent unhealthy blood sugar spikes after breakfast the following day.

Exercise regularly 

Exercising is one of the best hacks for a healthier gut and may increase microbiome diversity. Even low intensity workouts can help maintain a healthy gut.

Time your meals

Research into the effects of meal timing and intermittent fasting on the gut is still limited, but some evidence suggests the microbiome may have its own circadian clock

Prof. Tim Spector, ZOE’s cofounder and microbiome expert, recommends limiting snacking and not eating late in the evening to allow your gut time to rest during the night. This keeps the lining of your gut healthy, which is important for gut health and your immune system. 

Take antibiotics only when necessary 

Antibiotics save lives, but their use can change your microbiome, and these changes can last. Take antibiotics only when necessary and always as directed by your healthcare professional.

Reduce stress

Whether psychological, physical, or environmental, stress may also disrupt the structure and function of your microbiome, leaving you more vulnerable to “bad” gut bugs. Finding ways to reduce your stress levels may therefore also improve your gut health.

Avoid smoking

In addition to increasing risk of chronic intestinal disorders and digestive tract cancers, smoking has been linked to altering your microbiome composition in ways similar to IBS and obesity. 

The magical microbiome

Think of the microbiome as a fingerprint — each one is completely unique. 

Humans share 99% of their DNA, but ZOE’s research has shown that genetics only plays a minor part in microbiome composition. Identical twins only share 34% of their microbes — and unrelated people only 30%.

Like your brain, your microbiome provides essential support for numerous health functions.

ZOE can identify the bugs that reside in your gut and help you understand the best foods to eat to boost your individual gut health.

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Signs of an unhealthy gut

When the microorganisms in your microbiome are out of balance, your body and brain are more susceptible to illness and chronic disease. The medical term for this is dysbiosis.

Dr. Will Bulsiewicz, gastroenterologist, gut health expert, and author of Fiber Fueled, explains what to look out for if you are concerned about your gut health. 

“The most basic and most essential function of our gut is the digestion of our food. This includes the breakdown of ingested food, absorption of nutrients, and elimination of waste. When things are working properly, things are effortless and in rhythm,” says Dr. B.

“We are free to enjoy a diverse, abundant diet without restrictions or fear of symptoms. We also have regular, complete bowel movements to eliminate our waste,” he adds.

But what about when things aren’t working properly?

“As a gastroenterologist, I look for the earliest signs of a damaged gut — digestive symptoms. This may include bloating, gas, abdominal discomfort, nausea, or a change in bowel habits that could be diarrhea, constipation, or fluctuations between both,” he says. 

“Don't get me wrong, we all get these symptoms from time to time. But there's a difference between the occasional, rare event versus the person who has a pattern of recurrent symptoms. When a pattern of digestive symptoms emerges chronically, we know that the gut is struggling to keep up with the demands of digesting your food.” — Dr. Will Bulsiewicz

He adds that fatigue is one of the most common symptoms he sees in his clinic. Although he says there are many issues that could cause fatigue, he adds, “there is no doubt that people suffering with digestive symptoms also suffer from fatigue.”

One of the earliest signs of improving gut health that Dr. B. sees in his patients is an increase in energy.

Changing your diet can dramatically change your microbiome in a short time. In addition to our 8 best foods for your gut microbiome, there are three things that can damage your gut health, which you should limit: 

  • Restrictive diets: Your gut microbiome needs a balanced diet rich in diverse foods to thrive. Restricting food groups is not good for your gut. 

  • Artificial sweeteners: These substitutes may lack calories, but they also lack nutrients. Some studies suggest these intensely sweet alternatives may lead to changes in the gut microbiome.

  • Alcohol: Excessive drinking can alter your gut’s metabolic function and cause inflammation throughout your digestive tract.

The takeaway

You can improve your gut health if you eat what’s best for your body and your unique set of microbes.

For a happier, healthier gut, try to eat a rainbow of plant-based foods, ideally around 30 different types per week. A diverse diet supports a diverse microbiome. 

At ZOE, we believe in the “everything in moderation” philosophy — no food should be off limits, and you can have a healthy, balanced gut with a diet that occasionally includes ultra-processed foods or a glass of wine. 

But food is not the only way to improve your gut health. Get a good night’s rest, keep your body moving, be mindful of stress levels, take antibiotics only when you need them, and avoid smoking. These habits are also important in supporting the complex needs of your microbiome. 

Discovering what foods and behaviors will create the best environment for your gut to thrive begins with understanding what microbes make up your unique microbiome.

With the ZOE program, it’s possible for the first time to do a test and find out which of the 15 “good” and 15 “bad” bugs you have in your gut and what foods work best for you to improve your gut health. 


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