The 5 Food Pillars of Eating for Gut Health, According to a Registered Dietitian

Fiber—to feed healthy gut bacteria and regulate digestion.

When it comes to healthy digestion, fiber is a key player, providing structure to aid digestive regularity. There are two main types of fiber: soluble fiber and insoluble fiber, and we all need both since they provide different benefits. Soluble fiber dissolves in water to form a gel in the gastrointestinal (GI) tract. Whereas insoluble fiber does basically the opposite: It does not dissolve in water and adds bulk, helping to keep things moving and prevent constipation.

Certain types of fiber aren’t completely broken down in the digestive process and make it all the way to the intestines. These survivors are really important sources of food for our healthy gut bacteria and another name for them, that you may be familiar with, are prebiotics (which we’ll get to in a second). While not all sources of fiber are prebiotics, many familiar fiber-rich foods are, including bananas, apples, asparagus, berries, flaxseed, broccoli, garlic, oats, onions, leafy greens, tomatoes, and legumes including beans, lentils, and peas.

Prebiotics—to feed gut bacteria.

Prebiotics are typically soluble fibers that are indigestible by humans, but not by our gut bacteria. Prebiotics act as food for our intestinal bacteria, helping them to flourish. There are so many prebiotic foods available to us. Some examples of prebiotic food sources include barley, onions, garlic, leeks, honey, cocoa, flaxseed, seaweed, whole wheat products, dandelion greens, mushrooms, asparagus, cabbage, apples, oats, watermelon, bananas, and chickpeas.

Probiotics—to increase healthy gut bacteria.

An important way to start building a thriving gut microbiome is to introduce more healthy bacteria into the biome. This can most easily be accomplished by consuming foods rich in probiotics, a term for healthy bacteria. Probiotic foods will either be enriched with bacteria or bacteria will be grown in the food through fermentation. Fermentation is a metabolic process through which bacteria facilitate a chemical change in the food or beverage in question, producing desirable results. These results could be increased health benefits, longer shelf life, or enhanced flavor profile. Some fermented foods, like sourdough bread or beer, don’t contain probiotics, but many others do. A few fantastic ways to eat your probiotics include sauerkraut, tempeh, kombucha, miso, kimchi, kefir, yogurt, buttermilk, and certain types of pickles (that are actually fermented, not just pickled in vinegar).

Anti-inflammatory foods—to keep your gut happy.

A final pillar of gut-healthy food choices is eating foods that help your body fight and prevent inflammation. Pro-inflammatory foods can irritate the gut and negatively influence the microbiome, especially if consumed in excess, and this can inhibit the biome from carrying out its vital bodily functions. Generally, anti-inflammatory foods will be full of vitamins and minerals. Some will also provide omega-3 fatty acids, while others will contain important plant compounds. Polyphenols, or plant compounds, are particularly beneficial for gut health because they have antioxidant properties, encouraging healthy microorganism growth while inhibiting the growth of harmful pathogens in the gut.

Sources of polyphenols include berries, nuts, dark green veggies, tea, beans, apples, cherries, onions, olives, cloves, capers, oregano, sage, thyme,and many more. The list is long, because all plants will contain some of these amazing compounds (hence why eating more, and a variety of plants is fantastic for gut health). A good rule of thumb: The more brilliantly colored the plant food is, the more likely it’ll be packed with polyphenols. Other anti-inflammatory foods contain omega-3 fats: walnuts, chia seeds, hemp, salmon, sardines, anchovies, and soybeans.

Limit or omit gut-inflammatory foods when you can.

There are some foods and ingredients that unfortunately don’t support—or in some cases actively irritate—gut health. All foods have a place in our diets, and nothing is completely off-limits. However, striking the right balance and de-emphasizing the less-beneficial bites and drinks will be a game-changer for your microbiome. Mindfulness and moderation are key when it comes to inflammatory foods, many of which either inherently lack fiber or have been stripped of their natural fibers (think: refined grains). Alcohol, processed foods, added sugars, and fried foods fit into this category. Red meat is also something to be careful of, as research has found that consuming red meat can releases a pro-inflammatory metabolite the body that’s been linked to heart disease. (Plus, there’s robust evidence linking red meat to colon cancer.) Added sugars are also an ingredient to be wary of and limit wherever possible. Not only are they a major inflammatory agent in the gut, but research has shown that added sugars can negatively impact the balance of good and bad bacteria in the gut as well as compromise the gut mucosal barrier, leaving us more susceptible to illness and infection. Artificial sweeteners, too, may disrupt the balance of bacteria in our biome.