Prebiotics vs. Probiotics: What’s the Difference and Which Is Best?

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The topic of prebiotics versus probiotics is wildly confusing to many. Both are a part of the extensive ecosystem, or microbiome, that lives inside the human intestinal tract. But like the chicken or the egg, which came first—and which is more necessary? This is precisely what we will discuss in this article.

The difference between prebiotic and probiotic supplements varies greatly. I’ll share real-life examples that fit into these categories as we go. Don’t worry if you would prefer to avoid supplements and focus instead on food sources—those will also be covered. Let’s jump right in!

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What Are Prebiotics and Probiotics?

Probiotics are living microorganisms found in foods and supplements that have beneficial properties when introduced into the body, especially in the gut. They are often referred to as “good bacteria.” Once in the intestines, you may hear them called flora or microflora. Gut Health by Transparent Labs is one of our favorite probiotic supplements, featuring a variety of 10 different bacteria strains to colonize the gut. Probiotics are essential for athletes and active individuals. But how do we get these friendly bacteria to stay?

Feed them what they like—prebiotics! Prebiotics are the foods, mostly fiber, that probiotics eat in the gut. If we feed the probiotics what they like, they will be happy, procreate, and stay put. This then allows us to reap the benefits of probiotics indefinitely. Transparent Labs also makes a prebiotic, Prebiotic Greens, which provides a variety of prebiotic fibers in powder form. It’s intended to be mixed into a drink and promotes a thriving microbiome.

What Is the Difference Between Prebiotics and Probiotics?

The difference between prebiotics and probiotics boils down to the fact that probiotics are alive, while prebiotics are not. People often mix up the two due to the similarities in their names. Prebiotics are food for probiotics. For probiotics to be happy and want to stick around, they need food. And because many of us aren’t getting enough fiber from our diet alone, prebiotic supplements can be a great way to ensure the probiotics stay.

Prebiotic fiber is usually in the form of fructooligosaccharides (FOS) or galactooligosaccharides (GOS). On a microscopic level, these are long chains of plant carbohydrates. FOS doesn’t spike blood sugar. In fact, it has been shown to decrease fasting glucose and insulin levels.(1) Prebiotics are not digested until they make it all the way down to the colon, where they are fermented and eaten by healthy bacteria.(2)

Prebiotic and probiotic supplements can either be sold separately or combined into one supplement. For example, Jacked Factory’s Green Surge with Probiotics offers a healthy green drink with the benefit of six added probiotic strains. You could then take a prebiotic later to feed the friendly bacteria. Performance Labs makes Prebiotic, their FOS supplement, which is easy to swallow and does the job. There’s also the option of taking a supplement that offers both. Ritual makes Synbiotic+, which includes both a high-quality, clinically studied probiotic blend and a patented prebiotic, all in one capsule.

Benefits of Prebiotics and Probiotics

The benefits of prebiotics and probiotics run the gamut. Here are some benefits of each.

Benefits of Prebiotics

  1. Decreased harmful bacteria. Research shows that consuming prebiotics can help reduce the number of pathogens or harmful bacteria by stopping them from binding to the lining of the intestines.(3)
  2. Improved regularity and eased digestive discomfort. Thanks to the fiber in prebiotic supplements, they can often improve digestion. A great example of this is the fiber in GNC’s Prebiotic, which has been studied and found to positively affect gas, bloating, and stomach discomfort.(4)
  3. Immune support. It’s thought that along with probiotics, prebiotics play a role in immune health. Their presence can activate certain aspects of the immune system, such as the release of cytokines, or specialized immune secretions.(3)
  4. Increasing the friendly bacteria. Perhaps the most notable benefit of prebiotics is improving the overall population of healthy bacteria. Being that they are the food for probiotics, they encourage the long-term colonization of probiotics in the intestine.(3)

Benefit of Probiotics

  1. Treatment of gastrointestinal illnesses. Probiotics have been clearly demonstrated to improve certain gastrointestinal disorders, such as irritable bowel syndrome, ulcerative colitis, antibiotic-associated diarrhea, and others. Research is limited, however, because there isn’t a consensus on the use of probiotics for treatment, such as the most effective strains and dosage for each condition. Additionally, there is some evidence that probiotics are not beneficial for other GI diseases, such as Crohn’s or pancreatitis.(5)
  2. Immune Health. With a large portion of the immune system based in the gut, probiotics can play a direct role in improving immune health. Many people don’t realize that once probiotics make it to the large intestine, they interact directly with immune system cells. They increase the production of cytokines and chemokines, which are immune proteins that affect other cells and direct white blood cells where to go. This is just one example of probiotics and their impact on your immune response. They also activate T cells and help protect against specific pathogens.(6)
  3. Anti-inflammatory effects. Probiotics have anti-inflammatory effects. However, research still needs to be done to clarify how they are able to impact inflammation. It is likely related to their relationship to immune response. They improve mucus secretions and uphold tight junctions in the intestinal lining, which helps to maintain immune function and to decrease the development of inflammatory biomarkers.(7)
  4. Targeted improvement. As our knowledge of probiotics evolves, scientists are finding links between certain probiotic strains and specific outcomes. For example, Kaged Pro-Biotic is a probiotic targeting athletes. Their patented probiotic strain offers a variety of benefits and has been proven to increase muscle mass.(8) There are many other patented probiotic strains intended to support certain areas, such as cardiovascular health and cancer prevention.(9)

After reading about the differences and benefits of prebiotics versus probiotics, you may want to choose a supplement that contains both for ease of use. Optimum Nutrition’s Prebiotic + Probiotic comes as a gummy, which makes remembering to take this two-in-one much easier.

Prebiotic and Probiotic Foods

You can also get your pre- and probiotics from food sources. Let’s break it down here.

Prebiotic Foods

Prebiotic foods contain FOS and are fermented in the large intestine for healthy bacteria to consume. Foods containing FOS include:

  • Oats
  • Bananas
  • Apples
  • Garlic
  • Onions
  • Leeks
  • Asparagus
  • Barley

This is not an all-inclusive list. A diet rich in whole grains, fruits, and vegetables will likely provide you with a good volume of healthy prebiotic fiber.

Probiotic Foods

Most fermented foods contain probiotics. Look for:

  • Yogurt
  • Kefir
  • Kombucha
  • Sauerkraut (fresh, refrigerated only)
  • Kimchi
  • Miso
  • Pickles (fresh, refrigerated, vinegar-free)

You’ll notice that many of these foods have caveats requiring them to be refrigerated. That’s because the more processed, shelf-stable foods often contain additives that cannot support live probiotic cultures.

Prebiotic and Probiotic Supplements We Recommend

Prebiotic Supplements

Probiotic Supplements

Pre/Probiotic Blends

FAQs About Prebiotics vs. Probiotics

Is it better to take a prebiotic or probiotic?

To reap health benefits, it’s important to take live probiotics. If you don’t eat a variety of fiber, it can’t hurt to take a prebiotic as well. A prebiotic can be taken either in combination with or alongside the probiotic.

Do you need both prebiotics and probiotics?

Our gut microbiomes have naturally occurring bacteria. To introduce more diverse and beneficial bacteria, probiotics should be consumed by taking a supplement or eating foods with probiotics. To entice the beneficial bacteria to stay, you should consume prebiotics, either in the form of foods or as a supplement.

Who should not take prebiotics?

Some individuals who experience adverse GI effects from fermented fiber, such as certain people with IBS, should avoid prebiotics or consider an elimination diet to determine which are tolerated the best. Additionally, prebiotics are not suitable for those on a low FODMAP diet or those with Small Intestine Bacterial Overgrowth (SIBO).

What are the signs that you need prebiotics?

If you are not reaping the rewards from your probiotic, you could benefit from adding in a prebiotic to encourage a thriving microbiome. Check with your healthcare provider before starting a new supplement.