Taking prebiotic supplements is one way to help boost gut health — and they can often be effective.

But experts still say prebiotic-rich food is the way to keep our thousands of species of gut bacteria happy and healthy.

“That’s because vitamins and minerals are most potent when they come from food...” Harvard Medical School explains. “Plus, food tastes better than supplements and is often less expensive.”

Fortunately, prebiotics are found in multiple kinds of food, from fruits and veggies to nuts, grains and spices.

“And with so many options of prebiotic rich foods, you can find the sources that best work for you and your digestion. Your gut - and your whole body - will thank you,” Brown University Health advises.

Tennis star Roger Federer eats a banana while at a tournament in Montreal, Canada, in August 2017. Bananas and many other foods are rich in prebiotics that can boost gut health (Getty Images)

Bananas

The yellow banana you may be familiar with is a Cavendish banana. The majority of its 27 grams of carbohydrates are prebiotic, whereas some supplements only have 2.5 grams.

Getting just three to five grams of prebiotics each day has been shown to be beneficial to your gut health, according to Texas’s Lubbock Gastroenterology.

Bananas have insulin, a natural hormone that turns foods into energy and regulates blood sugar.

Insulin is also a prebiotic fiber and bananas are high in resistant starch, which has prebiotic effects, according to dietitians at Healthline.

Reachers say this is the case‘regardless of the type of banana,” of which there are more than 1,000.

Asparagus

Asparagus contains insulin and other forms of fiber that support a healthy gut.

A quarter pound has at least five grams, according to Colorado State University.

“It has lots of fiber and beneficial nutrients,” registered dietitian Carly Sedlacek told the Cleveland Clinic.

Apples

The majority of the more than 4 grams of fiber in apples is prebiotic.

The fruit contains a prebiotic fiber known as pectin that helps to improve inflammation and lower cholesterol levels.

“It also contains plenty of polyphenols, which have a prebiotic effect on the gut microbiome,” registered dietitian Dr. Emily Leeming told Vogue.

A farmer eats an apple in Madrid, Spain, in September 2014. Apples are another prebiotic fiber-rich fruit (Getty Images)

Garlic

Garlic is lower in fiber than other fruits in vegetables on the list. But, it has several hundred milligrams of prebiotic fiber per gram of food, according to scientists.

“Approximately 17 percent of the fiber found in garlic are prebiotics. These prebiotics includes inulin (around 11 percent) and FOS (around six percent),” according to microbiome company BIOHM Health.

It also helps to support the growth of beneficial bacteria and fight off harmful bacteria, according to previous research.

Oats

Oats have about eight grams of fiber per cup – a substantial amount of which is prebiotic – and are a source of resistant starches that end up as food for our microorganisms.

When resistant starches are broken down, they often produce butyrate, a fatty acid that helps the immune system and with hydration, according to the Cleveland Clinic.

“If you’re eating foods that help produce butyrate, and you have the right bacteria in your gut, then your butyrate levels will be higher, which has been shown to have all these beneficial effects,” says registered dietitian Dr. Gail Cresci.