You probably already know that that probiotics are key for keeping your gut healthy. But herbalist, health coach, and Supernatural founder Rachelle Robinett says there’s another substance that can majorly boost gut health: acacia fiber. It’s so beneficial that it’s the starring ingredient in her Supernatural Smoothie, which she whips up in the latest episode of Well+Good’s YouTube series, Plant-Based.

“Acacia fiber is a form of prebiotic fiber,” Robinett explains in the episode. “It’s a soluble fiber and what your gut bacteria need to live.” Basically, the acacia fiber feeds the probiotic bacteria in the gut. This, Robinett says, helps the body better digest and absorb food, which in turn leads to more energy, a better mood, and all sorts of other benefits. It’s no surprise that acacia fiber has become a popular (and more natural) way for brands to add fiber into their products—like Bulletproof’s forthcoming high-fiber powder, InnerFuel.

Robinett shares up her go-to, fiber-backed smoothie recipe that just so happens to be rich in acacia fiber. But if you want to know how to make it, you have to watch the video above for the full scoop.

Health experts are all-in when it comes to fiber, but there are some things you should know before adding it in earnest to your diet. And another wellness beverage Robinett likes to sip on: sparkling beauty water.