How To Build The Ultimate Gut-Friendly Smoothie, According To A GI Doctor

The good news: As a board-certified gastroenterologist and gut health expert, I'm more than happy to play the Beyoncé to your bacterial song and dance by sharing a few of my absolute favorite smoothie ingredients.

When things are working the way they're supposed to, we have a diverse, abundant community of microbes living in harmony in our colon. The colon itself is healthy and strong with an intact barrier of cells to keep everything in its rightful place. In this setting, our microbes reward us with a long list of benefits, including:

Yeah, so that basically sounds like nirvana, doesn't it?

This is problematic because now the colon wall is no longer protected by a healthy community of anti-inflammatory bugs, and the result is damage to the tight junctions holding the colon wall together and an increase in intestinal permeability that leads to the spillage of something called bacterial endotoxin into the bloodstream. This bacterial endotoxin jumps on the vascular superhighway throughout the body, and wherever it goes, it sets a fire (better known as inflammation). It's bad news!

I know, it's a lot of info, but in order to create this ultimate gut health smoothie, we need to understand what could be causing problems in the first place, as well as how to restore balance to the microbes, shore up the tight junctions, reduce intestinal permeability, and squash bacterial endotoxin release. Sounds tough, but it doesn't have to be. I promise, all you need is the power of plants. Here are the ones that will help you create the gut-healing smoothie of your dreams:

If we're going to talk about feeding our gut microbiota, we have to start with the single most important nutrient—fiber! Green bananas are a unique source because, in addition to soluble fiber, they contain resistant starch. Resistant starch is a type of prebiotic that can trigger the release short-chain fatty acids1 (SCFAs), beneficial compounds that alter the bacterial balance to increase the good guys and decrease the bad ones while also strengthening the colon cells, repairing tight junctions to shore up leaky gut, and reducing bacterial endotoxin release. As the banana ripens, the resistant starch breaks down into sugar, so for optimal gut health, let's use the green ones.

OK, you're going to hear me talk about SCFAs again. Berries are also a rich source of fiber to promote SCFA release, but fiber isn't the only prebiotic. Berries also contain polyphenols, which are plant-based chemicals that give berries their color and have numerous health benefits. From a gut health perspective, they've been shown2 to swing the microbiome pendulum in our favor by selectively inhibiting the bad bacteria while augmenting the good ones. No need to hold back on the berries in your gut-friendly smoothie!

When you take an excellent source of fiber and add in healthy plant-based omega-3 fatty acids, you get a unique source of prebiotics that, once again, boost the gut microbes that help you achieve that healthy gut list we talked about up top.

Yes, ground. That's because flaxseeds need to be ground to release their health-promoting benefits. Once you do, you get the fiber and plant-based omega-3 fatty acids that you find in walnuts—and then some. Ground flax is also a source of mucilage, a somewhat slimy, gelatinous substance produced by plants that promotes healthy bowel movements and supports the microbiota3.

But why do you want to throw 'em in your smoothie? Broccoli—and, therefore, broccoli sprouts—contains sulforaphane, a phytochemical that has been shown to increase healthy gut microbes, repair tight junctions, and reduce intestinal permeability and bacterial endotoxin release. And here's the magic: When you eat broccoli sprouts, you get up to 100 times more sulforaphane than you would get from fully mature broccoli. As you might have guessed, broccoli sprouts are bitter, so ease into using them.

While these five ingredients make for a great jumping-off point to create the ultimate gut-friendly smoothie, you are by no means required to stop there. Plant-based diversity is the key to gut health, so when you add more plants, you are rewarded with a healthier gut. Feel free to toss in a handful of greens, some chia seeds, or whatever suits your fancy.