Probiotics [1] 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 sauerkraut, kombucha [2], and 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. Since prebiotics and probiotics sound so similar, many may confuse the two [3] 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 colonized with the bacteria you want in there (and not colonized by bad bacteria like E. coli).

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 grocery cart:

• Pure maple syrup or maple sap: Pure maple syrup from Canada is a natural sweetener that is derived directly from the maple tree's sap that, when consumed in moderation, can be part of a healthy diet. Data shows that maple sap contains natural prebiotics called oligosaccharides [4] that support the growth of lactobacilli, the good bacteria found in some kombuchas, yoghurts, and supplements.
• Mushrooms: Mushrooms contain natural prebiotics that help support the microbiota. For meat-lovers or those who have a hard time sneaking prebiotic-rich veggies into their diet, mushrooms can be added to recipes like hamburgers or tacos for a prebiotic boost without affecting the flavour of the dish.
• Garlic: Garlic is naturally high in inulin, a type of nondigestible carbohydrate that acts as a prebiotic. Research suggests that a component in garlic stimulates the growth of the beneficial type of bacteria called bifidobacteria [5] and may actually help prevent some gastrointestinal diseases. Leeks, onions, and other foods in the allium family are typically a great source of natural prebiotics.
• 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 [6].
• Chicory root: If you look at the ingredient list of the protein bar you keep in your purse, you may see chicory root listed. Chicory root is actually the root of the endive plant and is a common ingredient in many foods to boost the fibre and prebiotic content.
• Bananas: 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. Now the only challenge is getting to the banana before it ripens!