The Best Foods For Gut Health You Should Be Eating

You may not realize it, but every time you eat, you're actually throwing a dinner party for the microorganisms that call your digestive tract home. According to a 2016 paper published in Current Opinion in Gastroenterology, the gut microbiome is an ecosystem of billions of microorganisms (mostly bacteria) that reside in your large intestine. It performs a number of important functions, including helping to break down food, producing certain vitamins, and protecting the body against foodborne pathogens. Everyone's gut microbiome is unique, but for optimal health, it's important that this collection of microorganisms be large and diverse.

Although the term "gut health" is thrown around a lot these days, a 2011 paper published in BMC Medicine noted that there's no scientific definition for what gut health is and how it can be measured. The authors did, however, highlight two important factors that underpin gut health: a robust, diverse microbiome of friendly bacteria and a well-functioning GI barrier. This barrier is more than just a physical separation of the inside of our digestive tract from the rest of our body; it also includes a complex collection of immune cells. So what foods should you eat to support a strong microbiome and a sturdy GI barrier?

Yogurt

When it comes to foods that are good for your gut, yogurt is the first thing that probably springs to mind. But what many consumers don't realize is that you don't have to buy yogurt intentionally fortified with beneficial bacteria. Yogurt is, by definition, a probiotic food because bacteria are needed to ferment milk into yogurt. Lactobacillus bulgaricus and Streptococcus thermophilus are the two strains that produce yogurt. As long as the yogurt isn't heat-treated after the bacteria do their work (and most yogurts aren't), these bacteria remain alive and active. If manufacturers decide to add additional probiotics after the yogurt is created, these usually include such strains as Lactobacillus casei, acidophilus, or reuteri (per Clinical Infectious Diseases).

If you do decide to eat yogurt fortified with probiotics, you may want to look for those that contain Lactobacillus acidophilus, as this particular strain has been associated with a number of benefits in addition to improved gut health, including lowering cholesterol and fighting yeast infections. Brands that contain acidophilus include yogurt giants like Chobani, Yoplait, and Fage (via Medical News Today).

The probiotics in yogurt may also be able to assist with inflammation, according to a meta-analysis published in Obesity Medicine in 2020. The researchers noted that probiotic yogurt reduced levels of C-reactive protein (CRP), a marker for chronic inflammation, particularly in overweight individuals.

Sauerkraut

Sauerkraut is a probiotic food made from fermented cabbage and, according to Healthline, may contain up to 28 different strains of beneficial bacteria. One gram of sauerkraut boasts between 1,000 and 100 million colony-forming units (CFUs) of bacteria, which means that a half-cup (50-gram) serving provides 50,000–5 billion CFUs.

By helping to maintain a flourishing gut microbiome, probiotic foods not only improve your digestive health, they can also improve your immune system. That's because approximately 70% of your immune system resides in your gut, according to Essentia Health. Eating sauerkraut and other "living foods" can reduce your risk for respiratory infections such as the common cold. Essentia Health noted that "certain probiotics strains, Lactobacillus and Bifidobacterium, were found to lessen the duration of respiratory infections in adults and children."

Probiotic foods also offer protection against foodborne pathogens like E. coli. A study published in the journal Gut concluded that two probiotic strains, Streptococcus thermophilus and Lactobacillus acidophilus, protect the epithelial cells lining the intestinal tract from E. coli. These probiotic strains appear to make it more difficult for E. coli to adhere to and penetrate these epithelial cells.

Red wine

Unlike other types of alcohol, wine — especially red wine — has a reputation for being good for your health when consumed in moderation. Most of these purported benefits stem from plant chemicals called polyphenols found in wine grapes. Polyphenols have powerful antioxidant and anti-inflammatory properties. Scientists have identified more than 8,000 polyphenolic compounds, but the one most prominent in red wine is resveratrol (via Healthline).

If you're not a big fan of yogurt or sauerkraut, you'll be thrilled to hear that the polyphenols in your nightly glass of red wine could be doing just as much as these other fermented foods to support a healthy gut microbiome. A 2018 paper published in Food Research International found that not only can the polyphenols in grapes and red wine have a positive influence on the number and types of beneficial bacteria in our intestines, the microbiome can in turn play a role in how much of the dietary polyphenols we consume get absorbed. A 2012 study published in The American Journal of Clinical Nutrition concluded that the polyphenols in red wine may act as a type of prebiotic, essentially serving as food for our friendly bacteria.

Avocado

In case you needed one more reason to add avocado to every burger, salad, or piece of toast that crosses your path, you should know that avocado is full of gut-nourishing fiber. A single avocado contains 13 grams — roughly half of your daily requirement (via MyFoodData).

Fiber is a form of undigestible carbohydrate. It comes in two forms: soluble and insoluble. Soluble fiber absorbs water as it moves through your intestines, creating a gel-like substance that helps lower cholesterol and blood sugar levels. Insoluble fiber, on the other hand, adds bulk to stool and helps it move through the digestive tract, promoting regularity. Many Americans need to up their fiber intake. Average consumption is only around 15 grams (via UCSF Health).

Although humans can't digest fiber, our friendly gut bacteria can and do. As a 2020 paper in Nutrients explained, our gut microbiome breaks down and feeds off of this fiber. In the process of breaking down the fiber, bacteria produce short-chain fatty acids, which appear to have numerous health benefits for us humans. There's plenty of evidence that eating a fiber-rich diet is necessary to support a large and diverse microbiome. Certain types of bacteria may have preferences for different types of fiber, so while avocadoes are a good place to start, it's important to eat a variety of fiber-rich foods.

Potatoes

Potatoes aren't considered a high-fiber food (via Healthline), but they're a rich source of another important but undigestible nutrient: resistant starch. According to Clean Eating, resistant starch is a type of fermentable fiber that has properties of both insoluble and soluble fiber. It passes undigested from the small intestine to the large intestine, but once there, it becomes food for the beneficial bacteria that live in our colon. The bacteria produce butyric acid as they metabolize the resistant starch, and the cells lining our colon use this butyric acid as their main energy source. So the resistant starch provides food for our gut bacteria, which in turn provide the fuel our intestinal cells need to stay healthy and well-functioning.

Cooking potatoes and then allowing them to cool before eating increases their resistant starch content. Some people add raw potato starch to smoothies, oatmeal, or yogurt to sneak more resistant starch into their diet. Potato starch — a white flour-like powder similar to cornstarch — is about 80% resistant starch. While it's not as tasty as eating an actual potato, you'll only need one or two tablespoons a day to keep your friendly bacteria happy (via Healthline).

Green juice

Green juice may not look super appetizing, but it's becoming increasingly popular. According to Shape, green juice has graduated from niche health food to national obsession. The beauty of green juice is that you can include a wide variety of vegetables and fruits, adding whichever ingredients offer the nutrients or taste you're looking for. Per Healthline, common veggie ingredients include kale, spinach, Swiss chard, celery, wheatgrass, and cucumber, while berries, citrus fruits, apples, and kiwis are all popular fruit options that offer their own micronutrients and a bit of sweetness. You can also add herbs like parsley, mint, or ginger for a boost in both flavor and nutrition. It can be a convenient way for people to get more healthy fruits and veggies into their diet. But juicing removes the fiber that our friendly bacteria love.

Even so, green juice appears to be good for our microbiome. In a study published in Scientific Reports in 2017, researchers investigated how a three-day diet of vegetable and fruit juices changed the microbiomes of participants. They found that Firmicutes and Proteobacteria bacteria significantly decreased, while Bacteroidetes and Cyanobacteria increased. The researchers pointed out that the bacteria that had increased in number were those most associated with weight loss. These positive changes to the gut microbiome, however, had partially reversed after 14 days of being off the green juice diet.

Jerusalem artichoke

If you want to improve your gut health, make sure you get plenty of inulin. Inulin is a form of fermentable soluble fiber that serves as a prebiotic. It falls into a group of molecules known as fructans. Fructans can't be absorbed in the small intestines and instead become food for our friendly bacteria in the large intestines. Small amounts of inulin can be found in a variety of plant foods, and it's also available as a supplement, usually derived from chicory root (via Medical News Today). But if you want to get a sizeable serving of inulin from a whole-food source, add Jerusalem artichokes to your shopping list. Despite its name, the Jerusalem artichoke (or sunchoke) is part of the sunflower family. This tasty root vegetable is 14–19% inulin by weight (via Livestrong).

In a 2019 study published in The American Journal of Clinical Nutrition, researchers had participants eat a high-inulin diet for two weeks. The controlled diet provided 15 grams of inulin per day. Subjects' microbiome diversity and activity were assessed immediately before and after the diet, and then three weeks after returning to a normal eating pattern. The researchers found that immediately after the high-inulin diet, the proportion of Bifidobacterium bacteria, a group of bacteria closely linked to good gut health, had increased. The changes, however, had reversed at the three-week follow-up, suggesting that we need to keep these bacteria well-fed with fructans and other prebiotics if we expect them to stick around long-term.

Beans

Beans, beans, the magical fruit. The more you eat the more you ... feed your friendly gut bacteria. That's because beans are a rich source of galacto-oligosaccharides (GOS). GOS are chains of galactose (a type of simple sugar) that serve as food for our friendly gut bacteria. In addition to beans, GOS can be found in dairy products and some root vegetables (via WebMD).

Although great for gut health, GOS and some other prebiotics (including fructans) may actually cause GI issues for some individuals, thanks to their status as FODMAPs. As Healthline explained, FODMAPs (fermentable oligo-, di-, and monosaccharides, as well as polyols) are a group of "nondigestible short-chain carbs that are osmotically active, meaning they force water into your digestive tract." And because gut bacteria release gas as a byproduct as they feed on these carbohydrates, FODMAPs may cause bloating, abdominal discomfort, and a change in bathroom habits. 

As many as 60% of people with irritable bowel syndrome (IBS) are sensitive to at least one FODMAP. For these individuals, following a low-FODMAP diet can be helpful. But for individuals without IBS, following a low-FODAMP diet can do more harm than good because it robs your gut bacteria of the fuel they need to thrive.

Onion

Onion is a rich source of fructooligosaccharides (FOS), another type of nondigestible carbohydrate that serves as prebiotic fuel for our friendly gut bacteria, as well as improving calcium absorption. In addition to feeding our good bacteria, FOS can also help keep invading disease-causing bacteria at bay (via ScienceDaily). As a 2002 paper published in Digestive and Liver Disease noted, FOS stimulate the growth of friendly Bifidobacterium species while simultaneously "suppressing the growth of potentially harmful species such as ... Clostridium perfringens in the colon."

As the Centers for Disease Control and Prevention (CDC) explained, Clostridium perfringens (C. perfringens) causes nearly 1 million illnesses in the United States annually. When ingested, this bacteria releases a toxin that causes GI upset. People can get C. perfringens from eating infected undercooked meat, as well as from eating properly cooked meat and meat-based gravies that have been kept at an unsafe temperature (40°–140° F) for too long. That's because C. perfringens make spores. While thorough cooking kills the bacteria, the spores can survive the oven or stove and, if allowed to sit in this dangerous temperature zone too long, will grow into new bacteria. While asparagus or any other food is no substitute for proper food safety, the prebiotics it provides may give your gut a boost when it's under attack.

Asparagus

Asparagus is another food high in fructooligosaccharides (via ScienceDaily), but it has another gut-boosting trick up its sleeve. As dietitian Robin Foroutan explained in an interview with Parade magazine: "Asparagus may also help your body eliminate certain pesticides, and some pesticides, like glyphosate, are suspected of being bad for gut health." This assertion that pesticides are bad for your gut was echoed in a 2020 paper published in the Journal of Agricultural and Food Chemistry. The authors noted that exposure to pesticides appears to negatively affect the composition of the gut microbiome and hinder its ability to perform its critical functions.

And chances are good your gut needs asparagus's glyphosate-eliminating abilities, because many staple crops, including oats, soybeans, and corn, are sprayed with the stuff. According to an article in Health, "glyphosate is the most widely used herbicide in the world, and is used in hundreds of weed-killing products." In theory, foods that are contaminated with glyphosate residue don't contain enough of the chemical to be harmful to humans. But not everyone agrees on what, exactly, a safe level is. The Environmental Protection Agency (EPA) has set a daily tolerable limit of 30 parts per million (ppm). The Environmental Working Group (EWG), however, has set a limit that's more than 60 times lower than the EPA's. The EWG cautioned that "legal is not the same as safe" and opted for the stricter guideline to account for the fact that children may be more sensitive to the effects of glyphosate.

Pineapple

In addition to being delicious, pineapple is a double whammy when it comes to gut health. First, it's a solid source of microbiome-nourishing fiber, offering 2.3 grams in just one cup of fresh chunks. Second, it's the only dietary source of bromelain. Bromelain is a group of enzymes that help break down proteins. In addition to aiding digestion, bromelain has anti-inflammatory, anti-cancer, and immune-boosting properties (via Healthline).

According to a 2018 study published in the Journal of Food, bromelain may have a direct positive effect on the gut microbiome. The researchers found that feeding rats a supplement containing equal parts bromelain and the soluble fiber inulin significantly increased the number of beneficial Bifidobacterium and Lactobacilli bacteria in the rodents' guts. The bromelain-inulin combo also increased the amount of short chain fatty acids (byproducts produced by friendly gut bacteria) by 54%–95%. Although humans obviously aren't rats, their research suggests that bromelain could improve the composition and activity of our own microbiomes.

So how much pineapple do you need to eat to get the gut-boosting benefits of bromelain? Not as much as you may think. According to Livestrong, a commonly cited dosage for bromelain is 40 milligrams three or four times a day. That's equivalent to about two regular-sized slices of fresh pineapple.

Olive oil

Trying to keep track of which oils to use and which to avoid can leave your head spinning. But olive oil has maintained its popularity and solid reputation for years, and there's good reason for that. 

According to a 2021 paper published in Frontiers in Plant Science, most of olive oil's purported health benefits stem from the oleic acid it contains. This omega-9 fat makes up 55%–83% of the total fat in olive oil. Oleic acid has potent antioxidant and anti-inflammatory properties that make olive oil a powerful tool in the fight against cardiovascular disease, stroke, diabetes, and other chronic conditions. These same properties also make it great for gut health.

As a 2021 paper published in Nutrition Reviews explained, extra-virgin olive oil stimulates the growth of beneficial bacteria, reduces the numbers of disease-causing bacteria, and increases the amount of short-chain fatty acids the beneficial bacteria can produce. It also strengthens the mucosal lining of the intestines, which serve as a barrier between the digestive tract and the rest of the body. It can positively influence the expression of genes in intestinal cells, as well as stimulate production of immunoglobin A, a type of immune system molecule found predominantly in the digestive tract.

Salmon

According to the National Institutes of Health (NIH), salmon is one of the richest sources of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the two most beneficial types of omega-3 fats. A 3-ounce serving of farmed Atlantic salmon has 1.24 grams of DHA and 0.59 grams of EPA, while the same portion of wild Atlantic salmon has 1.22 grams and 0.35 grams, respectively. You probably already know that omega-3s are important for brain health and reducing your risk of cardiovascular disease, but did you also know omega-3-rich foods like salmon are also good for your gut microbiome?

In a 2017 study published in Scientific Reports, researchers asked 876 women in the United Kingdom about their diets, took blood samples to test the levels of omega-3s circulating in their bodies, and used stool samples to gauge the diversity of their microbiomes. The study authors found that individuals with higher levels of omega-3 in their blood also had a more diverse microbiome and a larger percentage of the bacteria species that have been identified as particularly beneficial. The stool samples of people who consumed a lot of omega-3s also contained higher levels of a compound known as N-carbamyl glutamate (NCG). NCG is produced by our gut bacteria and appears to have anti-inflammatory and antioxidant properties in the digestive tract.

Bone broth

There's more to good gut health than just your friendly bacteria. The lining of the gut also plays a key role. As a 2020 article published in Frontiers in Cellular and Infection Microbiology explained, "The mucus layer is the first line of defense against infiltration of microorganisms, digestive enzymes and acids, digested food particles, microbial by-products, and food-associated toxins." When this barrier is compromised, it can have wide-ranging negative effects in the rest of the body.

So how do you keep your gut lining strong? One great option is bone broth. More than just a simple stock, bone broth is made by simmering animal bones and connective tissues over many hours. This releases valuable vitamins and nutrients and breaks down the collagen in the bones and connective tissues into gelatin. Gelatin contains the amino acid glutamine, which helps maintain the structural integrity and function of the intestinal wall. Glutamine has been shown to heal "leaky gut syndrome," a condition in which the gut lining is compromised, allowing material inside the digestive tract to enter the bloodstream, where it can wreak havoc throughout the body (via Healthline). Bone broth can be expensive to buy, but fortunately it's very easy to make. According to Healthline, all you need is a big pot of water, a few pounds of animal bones (any kind will work), a splash of apple cider vinegar, some spices, and time.