There is an old saying – you are what you eat, which at the time it was coined was intended to inspire understanding of the connection between food and physical well-being. The phrase still rings true for both physical and mental/emotional health. And the connection starts in the gut.

Gut health depends on many environmental factors that give rise to physiological responses that effect your whole body. Although this relationship is extremely complex, it’s important to understand how and why certain foods have a significant impact on the gut’s ecosystem.

One group of compounds known for digestive benefits, in addition to their antioxidant and anti-inflammatory properties, is polyphenols. Here are several foods that are great for gut health, many of which contain polyphenols.

Green tea

The polyphenols in green tea are great for the gut microbiome; compounds in green tea have prebiotic activity, shifting the microbiome in a positive manner. Research suggests some of the bacteria in the gut make new bioactive compounds from the tea itself – providing benefit for the GI tract and other parts of the body.

There are many ways green tea can be prepared, but one way I enjoy its GI benefits is to use a high-quality canned coconut milk (free of stabilizers and gelling agents) to make a green tea latte. Matcha, which is a stone ground green tea, works best. You can make it your own by adding dark berries or chocolate, which also support the gut.

Or if you would like a greens formula containing matcha, try adding a scoop of Thorne’s Daily Greens Plus to the coconut milk instead of only matcha. But you might want to prepare it iced because heating it can change the flavor – and not necessarily in a good way!

Dark berries

Dark berries like blueberries, raspberries, and blackberries have two important constituents that benefit the GI tract – polyphenols (ellagic acid and anthocyanins, for example) and fiber. To receive the benefits of both, it's easiest to eat them. Like green tea, there is a complicated interaction between polyphenols, the microbiome, and the creation of bioactive compounds. Although the above berries exert positive effects on the microbiome, some, like raspberries, have additional benefits. Bugs in the gut microbiome exposed to ellagic acid and other polyphenols in raspberries synthesize the bioactive compound urolithin A, which supports healthy aging and muscle endurance.

There are endless ways to incorporate these foods into your diet – from smoothies and homemade popsicles for the summer (check out paletas recipes) to salads. Or just keep a bowl of them handy!

Chocolate

Chocolate is rich in polyphenols and, like the other big players on this list, it also serves up a heaping helping of healthy foods for the microbiome. And, like the other polyphenols discussed, chocolate polyphenols also have a complex relationship with the gut.

Chocolate is very versatile and can be used in smoothies, lattes, and of course, warmed up by itself. If you’re looking for something different to try, a mole (pronounced moh-lay) sauce might be right up your alley. It’s a spicy sauce used in Mexican foods that has numerous iterations, one of which includes chocolate. You can layer in some fun GI foods by creating a mole sauce for fish (preferably mahi-mahi or salmon); dust the fillet with tiger nut flour, pan sear it, and voilà! A perfect blend of resistant starch (more on this below), omega-3 fatty acids, and polyphenols. Need a side? Try fried green plantains, also known as tostones (fried green plantains – see below), or blueberry salsa.   

As a disclaimer, this should not be viewed as a free pass to run out and buy a candy bar. It’s the cacao in chocolate that contains its health benefits, not the added sugar, milk, and other ingredients that make it taste yummy.

Tiger nuts

These little superfood powerhouses aren’t related to nuts at all. They are a special extension of a stem called a tuber and have become a popular alternative milk source, particularly in specific diets like the paleo diet. Each tuber is about the size of a chickpea and is touted for its nutrient-dense nature. More importantly, tiger nuts are a great source of resistant starch (named for their resistance to being digested). They act like insoluble fiber in terms of digestibility, but are water soluble, like soluble fiber, which makes them fermentable in the colon. This process provides numerous benefits for the microbiome, such as increasing butyrate – a health-promoting short-chain fatty acid.

One way to incorporate tiger nuts in your diet is to make what’s called “horchata de chufa.” Although there are plenty of recipes online, stick with one that has no added sugar. A study using a traditional preparation of tiger nut horchata found that one serving a day over three days resulted in a positive shift in microbiome profiles, similar to the effect of a Mediterranean Diet.1 

Green bananas/plantains

Green bananas and green plantains are other great clean-label options for resistant starches. They have some of the highest amounts of resistant starch in foods. But don’t let them ripen because the resistant starch will convert to regular starch.

How do you prepare them? You can buy these bananas in the form of flour in most places – making them suitable for sprinkling in smoothies. Or consider making a fun GI brownie with banana flour, tiger nut milk, and chocolate (limit the sugar of course). If you can get whole green plantains or green bananas in your area, then try making tostones (fried green plantains) or a fun Puerto Rican dish guineítos (savory green bananas) to mix it up a bit. In addition to benefitting your GI tract, green bananas have also been shown to support healthy weight and metabolism – an extra bonus!

Lentils

No GI food list can be complete without lentils. This legume has it all – insoluble fiber, soluble fiber, resistant starch, and even polyphenols. Lentils are inexpensive and easy to prepare, so a winner all around. This versatile food is linked to numerous health benefits, both inside and outside the GI tract. You can thank your microbiome again for making bioactive compounds from the polyphenol-rich content inside the lentil.

Need some meal ideas? An internet search for white fish and lentils provides numerous options if you eat fish. Vegan or vegetarian? No problem. Use tiger nut milk, mushrooms, and beluga lentils to create a savory stew. Lentils also pair well with squashes for some tasty curries.

Fermented foods

I know what you’re probably thinking, “Of course, fermented foods offer beneficial bacterial cultures – we’ve heard this already.” Although you are correct that fermented foods like yogurt or sauerkraut are good sources of beneficial bacteria, I’m not here to talk about old news. Rather, I’d like to introduce some unsung heroes that are also found in fermented foods – bacteriophages. These little sentinels feed on “bad bugs” that might try to get a foothold in the fermenting foods. And this is pretty much how they work in the GI tract. They target bad species and remove them from your GI’s ecosystem, leaving more room for the beneficial bugs to proliferate. So, in addition to providing probiotics, fermented foods act as prebiotics, too.

Fermented food options run the gamut from sweet to savory. Just make sure you choose something that’s not pickled with vinegar, because pickling stops good bacteria in their tracks. Cauliflower rice bibimbap with a good kimchi is a great option. You’ll also get added benefits for the gut if you use a well-made gochujang sauce.

Fish

Because I’ve talked about several foods that contain specialized starches or polyphenols, including fish in this discussion might seem out of place. But I want to add it to illustrate the growing list of potential prebiotic foods that don’t contain starches/fiber and polyphenols. Fish are important because they are rich in omega-3 fatty acids, which have been shown to behave as prebiotics by positively altering the microbiome. They also help balance the milieu within the GI tract through modifications directly to the immune system and by supporting a healthy inflammatory response.

Whatever type of fish or recipe you try, be sure not to overcook it.

Not a huge fish eater? Don’t worry because supplementation with omega-3 fatty acids has also been shown to benefit the microbiome.*

Conclusion

Although I’ve suggested several food options that can benefit your gut, feel free to expand your search and your palate. Try layering the GI effects by incorporating several ingredients from this list. Your gut will thank you.

Bon Appétit!

Want to learn more about your gut health? Here is a small sample of the gut-health articles on Take 5 Daily:

Reference

  1. Selma-Royo M, García-Mantrana I, Collado MC, Perez-Martínez G. Intake of natural, unprocessed tiger nuts (Cyperus esculentus l.) drink significantly favors intestinal beneficial bacteria in a short period of time. Nutrients 2022 Apr 20;14(9):1709. doi: 10.3390/nu14091709.