Your Gut Needs Prebiotics and Probiotics—But What's the Difference?

We asked a gut health expert to give us the rundown on how both prebiotics and probiotics relate to your microbiome.

Between meditating, taking CBD, and drinking green juice, it's easy to be overwhelmed by the world of wellness. While some of these are just health trends (no thanks, detox tea), some are actually backed up by science and worth paying attention to. And given the importance of gut health, prebiotics should pique your interest.

You might be familiar with probiotics, the live microorganisms present in yogurt and fermented foods, but have you heard of their counterpart, prebiotics? Here, Rebecca Ditkoff, MPH, RD, a New York City–based registered dietitian and founder of Nutrition by RD, gives a full run-down.

The Difference Between Probiotics and Prebiotics

There are trillions of bacteria and other microorganisms residing in the lining of the digestive tract which play a key role in our health.

Probiotics are one of the most well-known parts of this complex system. "Probiotics are the 'good' bacteria that live in our guts and promote healthy digestion and also give our immune systems a boost. Although your digestive tract naturally produces probiotics, it is beneficial to also consume foods naturally rich in probiotics to increase your levels and the variety of strains of good bacteria," Ditkoff explains. Probiotics have been shown to help balance the microorganisms in the digestive tract and help repopulate the beneficial bacteria after, say, taking a round of antibiotics.

Prebiotics, on the other hand, are types of carbohydrates found in fiber-rich fruits and vegetables that are non-digestible by the body. Instead, they pass through your gut and provide a food source for those healthy bacteria (probiotics) and allow them to thrive. "It's important to note that all prebiotics are fiber, but not all fiber is prebiotic," Ditkoff says.

Nutritional Benefits

"Prebiotics and probiotics play complementary roles for our gut health, and work as a team to support your gut microbiome," Ditkoff says. They work together to maintain the balance of healthy bacteria by helping populate the live microorganisms themselves (the probiotics) and feeding those microorganisms (the prebiotics).

Eating Prebiotics and Probiotics

Probiotic-rich foods are often a byproduct of fermentation, which has been used for centuries in many cultures to preserve food and enhance health properties. In recent years, fermented foods have become more popular in the West as health-conscious consumers and practitioners recognize their impact on overall health, especially digestion. Look no further than the popularity of kombucha and sauerkraut for evidence. Probiotics have even appeared in skincare products, like Tula Skincare's de-puffing eye serum.

Probiotic-Rich Foods:

  • Kefir, a fermented milk drink similar to yogurt
  • Sauerkraut and kimchi, made by fermenting cabbage and other vegetables
  • Plain live organic yogurt (look for the words "live, active culture")
  • Fermented soybean products such as tofu, tempeh, and miso
  • Kombucha, a slightly fizzy drink made by fermenting black or green tea

Prebiotics can be naturally found in many fruits, vegetables, whole grains, and legumes that are high in special types of fiber.

Prebiotic-Rich Foods:

  • Alliums, such as garlic, onions, and leeks
  • Asparagus
  • Apples
  • Chicory root
  • Dandelion greens
  • Jerusalem artichokes (aka sunchokes)
  • Slightly under-ripe bananas

Probiotic Supplements

Many of us are familiar with the boxes and bottles of probiotics sold on drugstore shelves, promising to help with digestive woes. But is it worth the sometimes hefty price tag? Ditkoff says to not be so quick to pull out your wallet.

"In the U.S., probiotics are sold as dietary supplements, which do not undergo the testing and approval process by the FDA," she explains. "Manufacturers are responsible for making sure they're safe before they're marketed and that any claims made on the label are true. However, there is no guarantee that the types of bacteria listed on a label are effective for the condition you're taking them."

She also mentions that the health benefits of probiotics are strain-specific, and not all strains are created equal. Consult with your primary care provider or a registered dietitian (RD/RDN) to discuss options and your particular situation before taking a probiotic supplement.

Prebiotic Supplements

The truth is, research on prebiotic supplements is still in early stages, and many of the benefits are still largely theoretical. For those reasons, and because potentially helpful prebiotics can be found readily in many fruits and vegetables, it's best to consume your prebiotics naturally whenever possible.

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  1. National Center for Complementary and Integrated Health, Probiotics: What you need to know. Accessed October 28, 2022.

  2. Oniszczuk A, Oniszczuk T, Gancarz M, et al. Role of gut microbiota, probiotics and prebiotics in the cardiovascular diseasesMolecules. 2021;26(4):1172. doi:10.3390/molecules26041172

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