When it comes to gut health, not all fruits are created equal. Harvard-trained gastroenterologist Dr. Saurabh Sethi recently took to Instagram to break down which fruits help—and which might actually harm—our digestive system.
His list has some surprising inclusions, including a common breakfast staple that he actively avoids.
Overripe Bananas Make the Blacklist
Topping the list of fruits to avoid? Overripe bananas.
Loved by millions for their sweetness and convenience, these “yellow Mars bars,” as Dr. Sethi describes them, are packed with sugar that can spike blood glucose and provide less nourishment for gut bacteria.
As bananas ripen, their resistant starch and dietary fiber decrease while sugar content skyrockets.
Resistant starch, found in slightly green bananas, resists digestion in the small intestine and ferments in the large intestine, acting as a prebiotic that feeds good bacteria.
That’s why overripe bananas earn a poor score, while slightly green bananas score a modest five out of ten.
Slightly Green Bananas Offer Digestive Benefits
Slightly unripe bananas have higher fiber content, which supports heart health, lowers the risk of type 2 diabetes and bowel cancer, and helps prevent constipation.
Fiber—commonly known as roughage—also aids digestion and helps us feel fuller for longer.
Kiwis Bring Soluble Fiber to the Table
Kiwis stand out as a gut-friendly choice, offering about 2 grams of soluble fiber per 80-gram serving.
Soluble fiber attracts water in the digestive tract, forming a gel that eases constipation and promotes regular bowel movements.
Experts stress that frequent bowel movements reduce prolonged contact between waste products and the colon lining, lowering the risk of digestive cancers.
Blueberries and Pomegranates Lead the Pack
Dr. Sethi’s top picks for gut health are blueberries and pomegranates.
These fruits are loaded with antioxidants, which help fight free radicals linked to diseases like diabetes and cancer.
Pomegranates also contain ellagitannins, powerful polyphenols that reduce inflammation—a known risk factor for heart disease.
A study from the University of Barcelona found that participants consuming diets high in polyphenols from berries, nuts, cocoa, and olive oil had a 46% lower risk of developing heart disease compared to those who ate fewer polyphenols.
Middle-of-the-Road Fruits
Fruits like melons, pears, and apples fall in the middle of the ranking.
Grapes and oranges, however, scored lower—two and three out of ten respectively.
While grapes are hydrating and rich in vitamin C and potassium, their overall nutritional impact is limited compared to other fruits.
Oranges are high in vitamin C, folate, and antioxidants, but research from the British Journal of Dermatology links high citrus consumption to a potential increase in skin cancer risk, likely due to photosensitizing compounds.
That said, vitamin C is vital for healthy skin, bones, blood vessels, and cartilage, and deficiencies can lead to scurvy.
The NHS notes that most people can meet their vitamin C needs through a balanced diet, though supplementation may be advised in some cases.
Making Informed Choices
Dr. Sethi’s rankings remind us that variety matters when it comes to fruit.
Choosing the right types—like blueberries, pomegranates, and slightly green bananas—can support gut health, while avoiding overripe options may help reduce inflammation and promote overall digestive wellness.