You may already know the link between good gut bacteria and gut health. These “good” bacteria do more than support digestion: They also influence mood, metabolism, weight, and the immune system while helping keep harmful microorganisms in check. Good bacteria grow all by themselves in the right environment or you can take probiotics.

Probiotics are important — but they won’t work without prebiotics. The right combination of both will make your gut stronger, regulate digestion, and improve your immunity. Where do you find prebiotics, and how do you know you’re getting them from the best sources?

Here is everything you need to know about prebiotics, where to get them, and why they matter for your well-being.

What are prebiotics, and how are they different from probiotics?

Your gut microbiome is made up of a variety of bacteria — both good and bad. Prebiotics help push out the bad guys while serving as food for the good probiotic bacteria.

Prebiotics pass through your small intestine undigested, then ferment in your large intestine to make helpful compounds. While fermenting isn’t always ideal in your food (fermented protein is no bueno), fermenting prebiotics is necessary in your gut to feed those good bacteria and help them multiply. Think of prebiotics as fertilizer for the probiotic bacteria in your gut: They deliver powerful nutrients to feed this bacteria, help them flourish, and make your gut biome more diverse.

Prebiotics are also generally more robust than probiotic supplements. Many probiotics die off when they come in contact with stomach acid or heat. Prebiotics feed the good bacteria already living in your gut without getting destroyed during digestion.

Key benefits of prebiotics

Since prebiotics feed the good bacteria in your system, getting more of them help you collect all the benefits of a balanced gut. Good gut health helps with nutrient absorption, immunity, and fat metabolism — plus, it just makes you feel better (and more regular).

Foods with prebiotics

Popular sources for prebiotics include foods like apples, onions, and tomatoes. The problem is that some prebiotic-rich foods cause harm as well as good, thanks to antinutrients described in The Bulletproof Diet roadmap – mold, lectins, high sugar, and other garbage that makes you foggy and fatigued.

Alternatively, you could get prebiotics in Bulletproof-approved foods like asparagus and radishes — but you’d have to eat a massive amount to get the full benefits. Plus, if you’re on a ketogenic diet, many veggies rich in prebiotics contain too many carbs and kick you out of ketosis.

And if you travel much or eat at restaurants, you can forget about getting enough veggies on your plate to feed your good gut bacteria.

You can also get prebiotics from certain foods rich in resistant starch, which is a form of prebiotic you won’t find in your average plate of cheesy pasta.[1] These foods make good carb re-feed options on a cyclical ketogenic diet like the Bulletproof Diet (which is better for your gut than a plain cyclical keto diet).

Prebiotic powder supplement

A good diet goes a long way toward making your gut healthier, but eating pounds of veggies comes with its own challenges. It’s hard to do when you’re traveling, transitioning to a better-quality diet, eating fewer carbs, or get tired of preparing the same greens over and over.

I discovered that when I traveled, I wasn’t getting enough veggies, and my gut bacteria diversity dropped to only 58 species. I began testing a variety of prebiotic powder supplements, and the result was that my gut bacteria count went up to an impressive 196 (measured by Viome.) Prebiotic supplements were the missing piece in my gut health regimen.

Bulletproof Coffee already contains the right fats that make me feel energized and full, and when I added the right blend of prebiotics to the blender, I was even less hungry. I didn’t know that was possible! Plus, I can stop begging the waiter for a fourth serving of asparagus.

I put together a careful blend of multiple prebiotics over the last 2 years, and now I’m really happy with it. The right prebiotic powder supplement can fill in the gaps and power up your immune system without taking extra time out of your day.

Look for a supplement with a variety of prebiotics that won’t make you bloat (or worse, give you disaster pants), and make sure it has no flavor so you will actually use it. I can’t even tell when it’s blended in my Bulletproof Coffee!

How to use prebiotics to improve gut health

You don’t have to eat your weight in asparagus to get your daily dose of prebiotics. Just adding 1-2 scoops of a supplement like InnerFuel to your Bulletproof Coffee, smoothies, or bone broth helps you get the prebiotics you need, too. Since it mixes into hot or cold liquids and contains 0 net carbs, you’ll have no trouble adding it to your daily routine. InnerFuel is keto-friendly too!

With the right balance of prebiotics, you’ll notice a difference in your digestion and your energy levels. Try it — your gut will thank you.