This 48-calorie snack keeps your immune system strong — and can help you poop

It’s sweet. It’s sour. It’s fuzzy. And it might just be the most underrated superfood in your grocery cart.

At just 48 calories a pop, this snack has been linked to everything from stronger immunity and glowing skin to deeper sleep and smoother, more reliable digestion.

In fact, one gastroenterologist even “prescribes” two a day to her patients to help keep them regular.

The kiwi — an egg-shaped fruit native to the mountains of Southwest China — is a nutritional powerhouse.

Its claim to fame? Vitamin C. One kiwi packs a hefty 64 milligrams, more than 80% of your daily recommended dose.

Since your body can’t make vitamin C on its own, getting enough from your diet is crucial. This antioxidant fights cell damage from free radicals, giving your immune system a serious boost.

“It helps your immune cells get to the site of an infection and then helps those immune cells eliminate whatever’s infecting your body,” Dr. John McDonnell, a pediatric immunologist, told the Cleveland Clinic. 

Vitamin C also speeds wound healing and boosts collagen production, which keeps skin firm and reduces wrinkles. It can even help fade dark spots, giving you a brighter, more even complexion.

But vitamin C isn’t the only health hero hiding in this fuzzy fruit. Kiwis deliver a rare combination of soluble and insoluble fiber that work together to promote healthy digestion.

“I hesitate to say there’s any one magic fruit out there that will cure all your gut health woes, but in some respects, kiwis do seem to rise above some of the other tried-and-true methods out there, like prunes or psyllium fiber,” Dr. Trisha Pasricha, a gastroenterologist, told Fox News Digital.

Studies have found that kiwis can boost bowel function and ease symptoms in people with irritable bowel syndrome. They also improve stool frequency and consistency, making them a natural ally against constipation.

Plus, the fruit acts as a prebiotic, feeding your gut’s good bacteria.

“It’ll take an unhealthy gut bacteria colony and start to make it a little healthier just in one day,” Dr. William Li, a physician and food scientist, said on a recent episode of “The Mel Robbins Podcast.”

If you need another reason to add kiwis to your grocery cart, their potential to help you get a better night’s sleep might seal the deal.

The tangy fruits are packed with serotonin, a neurotransmitter that helps product melatonin — the hormone that regulates healthy sleep cycles.

In a study of 24 adults, eating two kiwis an hour before bed led to “significantly” longer sleep, better sleep quality and a quicker time dozing off.

Research also suggests kiwis may support heart health, protect against eye disease and aid in weight management.

Want to get even more out of your kiwi? Try eating the skin.

Chomping down on the fuzzy outer layer boosts can boost its fiber content by a whopping 50%, and you’ll also get in extra antioxidants like vitamin E and folate.

But not everyone should skip the peeler.

“Besides a very unique mouthfeel, kiwi skins contain calcium oxalate crystals, also referred to as raphides, that can cause tiny scratches on the tender skin inside of the mouth,” Sarah Brekke, a culinary specialist, told Better Homes & Gardens. 

That can lead to a tingling or burning feeling, which could be especially uncomfortable for people with sensitive mouths or acid reflux.

Brekke also warned that kiwi skins are high in oxalates, natural compounds found in many plants. While usually harmless, oxalates can increase the risk of kidney stones in some people.