Prebiotics are essential for a healthy gut and immune system: 10 best foods to eat

Probiotics are being added to so many foods that it's simpler than ever to sneak them into your diet — and that's a good thing, since probiotic-rich foods, like yoghurt, contain healthy, live bacteria that can help boost your immune system, protect your gut, and more. But what few people realise is that just like any other living organism, the probiotics you're eating or drinking every day need to be fed in order to thrive. If they don't get enough fuel, they won't be able to do their essential work. Enter: prebiotics.

"Prebiotics are the fuel that feeds and nourishes probiotics," says Mumbai-based dietician and clinical nutritionist Geetanjali Shah. Since prebiotics and probiotics sound so similar, many may confuse the two or assume the terms are interchangeable. Just remember that prebiotics feed probiotics. So, if you're spending a good chunk of your paycheck on good-for-you foods and probiotic supplements, you should do the same with prebiotic-rich foods that "help ensure that your gut is continuing to be colonised with the bacteria you want in there, and not colonised by bad bacteria, like E. coli," says Shah.

How do you make sure you're getting enough prebiotics to support those probiotics? Make it a point to add the following foods to your diet:

Mushrooms
Mushrooms contain natural prebiotics that help support the microbiota, says Shah. For meat-lovers or those who have a hard time sneaking prebiotic-rich veggies into their diet, mushrooms can be added to recipes, like mixed vegetable or pasta, for a prebiotic boost without affecting the flavour of the dish.

Garlic
Garlic is naturally high in inulin, a type of non-digestible carbohydrate that acts as a prebiotic. "Research suggests that a component in garlic stimulates the growth of the beneficial type of bacteria called bifidobacteria and may actually help prevent some gastrointestinal diseases," says Kolkata-based dietician Anupam Dey. 

Onion
Similar to garlic, onions, and other foods in the allium family are typically a great source of natural prebiotics. "They're great at promoting healthy gut bacteria and reducing bloating," says Dey. Onions are also rich in the flavonoid quercetin, which gives onions antioxidant and anticancer properties, he adds.

Asparagus
Like garlic, asparagus contains inulin fibre, which acts as a prebiotic. "Adding asparagus to your diet may support gut health, as well as offer other potential benefits, like, reducing the risk of developing certain cancers," says Dey.

Bananas
They're not only rich in vitamins, minerals and fibre, but also contain small amounts of inulin. If you prefer your bananas when they're slightly under-ripe, you're in luck. "Green bananas are higher in resistant starch, which acts as a prebiotic," says Dey. The only challenge? Getting the bananas before they ripen.

Apples
Apples are rich in pectin fibre, which promotes healthy gut bacteria and helps decrease harmful bacteria. "Apples have been linked to improved digestive health and fat metabolism. They also have antioxidant and anti-inflammatory properties," says Dey.

Cocoa
Cocoa is also an excellent source of flavanols. "Flavanol-containing cocoa has powerful prebiotic benefits associated with the growth of healthy gut bacteria. It also has benefits for the heart," says Shah.

Flaxseeds
Flaxseeds are incredibly healthy. They're also a great source of prebiotics, says Shah. "The fibre in flaxseeds promotes healthy gut bacteria, promotes regular bowel movements and reduces the amount of dietary fat you digest and absorb," she says.

Oats
Whole oats are a very healthy grain with prebiotic benefits. They contain large amounts of beta-glucan fibre, as well as some resistant starch. Furthermore, they have been shown to slow digestion and help control appetite. "They increase healthy gut bacteria, improve blood sugar control and may reduce cancer risk," says Shah.

Barley
Barley is also high in beta-glucan fibre, which promotes healthy bacteria in the digestive tract, says Shah. It also seems to lower cholesterol and blood sugar levels.