When it comes to the best foods for gut health, staples like yogurt, sauerkraut, and sourdough may come to mind. While these options certainly do the trick, variety is also key to nourishing the gut microbiome. When gut health expert and author of How To Eat More Plants Megan Rossi, Ph.D., R.D. (aka The Gut Health Doctor on Instagram) joined us on the mindbodygreen podcast, she rattled off her favorite gut-friendly staples—and she thinks apples don’t receive nearly as much credit as they deserve.

They say an apple a day keeps the doctor away, and Rossi would wholeheartedly agree. Below, she highlights how the fruit can optimize your gut and metabolism.

Why apples are A+ for your gut & metabolism.

Your gut health affects so many bodily functions, including, yes, your metabolism. In fact, the gut-metabolism axis is very much real, as it refers to the intersection of gut health and metabolic function. Essentially, because of the interplay between your gut, your brain, and your hormones, the healthier your gut, the stronger your metabolism.

Here’s where apples come into play: “People don’t realize that an apple contains close to a hundred million bacteria,” Rossi explains. Plus, they contain a variety of fibers, which is key for gut heath. “The reason why fiber is linked to so many health outcomes is because it feeds our gut bacteria,” Rossi adds. “Although we talk about fiber like it’s one thing, there are close to a hundred different types of fibers, and we need [diversity] to get optimal gut health…there’s at least eight different types of fibers [in apples], which then feed different gut bacteria.”

In addition to their fiber content (which also helps you feel fuller for longer), apples—namely, red apples—contain the phytonutrient quercetin, which has been shown to fight free radicals and promote healthy aging, provide allergy relief, and support the immune system. Lastly, apples are a good source of vitamin C, with one medium apple providing 10% of the daily value. Not bad for a midday fruit break.

If you’re looking to nourish your gut bacteria and support your metabolism, look no further than a juicy apple—it’s time we give the classic fruit the credit it deserves. And for more of Rossi’s favorite foods for metabolic health, check out this article tune in to the full episode on Apple Podcasts or Spotify, or check out the video below!