You’ve heard of probiotics: the stuff you find in yogurt and kombucha that’s great for your gut. But prebiotics? Yes, they’re a thing and they’re just as important as probiotics. It’s important to know the difference and understand why you need both probiotics and prebiotics for the best gut health. So buckle up: we’re going on a ride that will get you more intimate with your gut than when Miss Frizzle took the Magic School Bus inside Arnold’s stomach.

What are probiotics and prebiotics?

Think of probiotics and prebiotics as partners in crime or peanut butter and jelly. They work together, or synergistically, to support your overall health. And while their names sound similar, they are quite different once you dig into the details.

Probiotics

Probiotics are live microorganisms, like bacteria, found in yogurt and fermented foods like kimchi and sauerkraut. The most common types of probiotics fall under two groups known as Lactobacillus and Bifidobacterium. Certain strains promote gut health by keeping bad bacteria in check, supporting your immune system, acting as an anti-inflammatory agent, and reducing the risk of developing conditions like Irritable Bowel Syndrome, Crohn’s disease, diarrhea, and more.¹ But probiotics also help digest food, help produce vitamins, and help you absorb medications.²

Prebiotics

None of this would happen if those little live organisms went hungry, however, and that’s where prebiotics come in. If probiotics are the bacteria your gut needs to stay healthy, think of prebiotics as their food. They’re indigestible fiber that are found in various fruits and vegetables, whole grains, and other sources. Probiotics feed off prebiotics to do their thing. So you really need both for optimal gut health.

Why are the gut bacteria beneficial?

All of this is important because gut bacteria isn’t just important for your physical wellbeing. Your microbiome, or gut probiotic composition, can also affect your mental wellbeing, too. That’s right. Your gut and your brain are connected via what’s known as the "Gut-Brain Axis," a series of bidirectional connections that are revealing links between your microbiome and mood, cognition, and mental health.³

Research is still being conducted, but so far, “several mood disorders, such as anxiety, depression, and autism spectrum disorders now have well-established links to functional GI disruptions, whereas GI disease (eg, irritable bowel syndrome, irritable bowel disease) often involve psychological comorbidities associated with alteration of the gut microbiome.”

How does food affect the gut microbiota?

Food entering your body could contain hazardous bacteria, and it’s the job of your gut microbiota, the makeup of all the bacteria in there, to keep the bad stuff at bay. Food also has the potential to introduce good bacteria, of course, so you can use your diet to make sure you’re feeding your gut prebiotics and probiotics to in turn keep your whole body healthy. Just how important is the food you eat to your overall gut health? Studies confirm that what you eat can significantly alter the probiotics in your body within 24 hours ⁴, so you have a lot of power to affect your microbiota in the food and drink choices you make.

Your Body and Prebiotics

So, to recap: Prebiotics, prebiotics, prebiotics. Without them, probiotics can not thrive and throw the whole system off balance.

Microbiota

By “whole system,” first we mean your microbiota, or the trillions of organisms that live in your gut. Throw your microbiota out of balance, and the rest of your body and mind will follow.

Metabolites

Because they’re not digested, prebiotics lead to changes in microbiota, as the gut bacteria ferments them. In this way, prebiotics are metabolites, or “a substance made or used when the body breaks down food, drugs or chemicals, or its own tissue.”⁵

Which foods are prebiotic?

The good news is that prebiotics are found in a wide range of foods, including apples, asparagus, a slightly underripe banana, chicory root, barley, oats, flax seeds, wheat bran, seaweed, Jerusalem artichokes, garlic, onions, artichokes, and leeks. Oh, and OLIPOP!

Prebiotics and the Body Takeaway

Take care of your microbiome by eating plenty of probiotics, and fuel your probiotics with prebiotics. You don’t need to consume prebiotics and probiotics together at the same time, but make sure you get both. Your body and your mind will thank you.

Sources

1. “Health Benefits of Taking Probiotics - Harvard Health.” Harvard Health. Harvard Health, September 2005. https://www.health.harvard.edu/vitamins-and-supplements/health-benefits-of-taking-probiotics.
2. “Probiotics: What Is It, Benefits, Side Effects, Food & Types.” Cleveland Clinic, 2020. https://my.clevelandclinic.org/health/articles/14598-probiotics.
3. Appleton, Jeremy. “The Gut-Brain Axis: Influence of Microbiota on Mood and Mental Health.” Integrative Medicine (Encinitas, Calif.) 17, no. 4 (2018): 28–32. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6469458/.
4. Singh, Rasnik K., Hsin-Wen Chang, Di Yan, Kristina M. Lee, Derya Ucmak, Kirsten Wong, Michael Abrouk, et al. “Influence of Diet on the Gut Microbiome and Implications for Human Health.” Journal of Translational Medicine 15, no. 1 (April 8, 2017). https://doi.org/10.1186/s12967-017-1175-y.
5. “NCI Dictionary of Cancer Terms.” National Cancer Institute. Cancer.gov, 2021. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/metabolite.

Meet our Expert This article is reviewed by Lauren Manaker MS, RDN, LD. Lauren Manaker is an award-winning registered dietitian, book author, and freelance writer. Her work can be found in many major media outlets and on her women’s health nutrition-focused Instagram account @LaurenLovesNutrition. Raised in sunny South Florida and now living in Charleston, South Carolina, she has a love for the ocean and would be living on a houseboat if she had her way. She currently lives with her husband, young daughter, and 70-pound rescue pup.