Skip to main content

What Are Prebiotics and Why Should We Be Eating Them?

By Christine Rosenbloom, PhD, RD, FAND, a member of the CLIF Nutrition Advisory Council.

The ideas and suggestions written below are provided for general educational purposes only and should not be construed as medical advice or care. The contents of this article are not intended to make health and nutrition claims about our products. Always seek the advice of a physician or other qualified health provider before beginning any physical fitness or health and nutrition related activity.

The human digestive tract is one of the most complex ecosystems on the planet. Often referred to as the “gut microbiome,” this system contains more than 38 trillion individual microorganisms.1 And its importance on human health has led experts to call it our “second brain”.2,3

Many factors can impact the health of our gut microbiome. While some like age and genetics are out of our control, there are several lifestyle factors that influence our microbiome including diet, the environment and drugs like antibiotics. In fact, research shows that the foods we eat may have the single greatest impact on the microorganisms found in our gut. Choosing gut-friendly foods, like those with prebiotics and probiotics can help support a thriving microbiome — specifically the beneficial (or “good”) bacteria that live there.

What Are Prebiotics and Why Should I Be Eating Them?

Prebiotics are plant fibers that stimulate the growth and activity of good bacteria living in the human digestive tract. Prebiotic fiber provides food to existing bacteria, keeping them healthy, growing and functioning at their best — ultimately helping to maintain the health of your digestive system.1,3,4

Prebiotics vs. Probiotics

The number of live organisms in fermented foods may vary depending on manufacturing processes.

What Is the Difference Between Prebiotics and Probiotics?

Prebiotics and probiotics are different but work together to support digestive health. Prebiotics are plant fibers that feed the good bacteria that already exist in your body, allowing that good bacteria to grow and multiply. Probiotics on the other hand are actual live microorganisms that add to the existing population of good bacteria in your gut. Probiotics can be found in yogurt, kefir, and some fermented foods.

Which is better - prebiotics or probiotics? The answer is both! Prebiotics and probiotics work in harmony to increase beneficial bacteria in our gut. Probiotics contain the live microbes that live in our gut and prebiotics are the energy source that feeds them.

How Can I Get Prebiotics Into My Diet?

Experts recommend 5 grams of prebiotic fiber each day to help increase the beneficial bacteria in our gut.1,3,4 Fruits, vegetables and whole grains like asparagus, bananas, garlic, leeks, onions, barley and oats contain prebiotic fiber, but it can be challenging to achieve the recommended amount of prebiotics from these foods alone.

Because of this, prebiotics are often added to foods like bars, drinks, and cereals to help us achieve the recommended amount needed to support digestive health. One of the most well-studied sources of added prebiotics is called inulin, which is a soluble fiber that comes from plants like chicory and agave. Research shows that healthy adults can tolerate up to 10 grams of inulin a day.5 If you typically eat a diet low in fiber, consider increasing the fiber in your diet gradually to allow your body to adapt and minimize the potential for gastrointestinal upset (e.g., stomachache, gas, bloating, etc.).

Introducing the New LUNA® Bar With 2.5g Prebiotics

Gut-friendly foods can support a balanced microbiome and foods like LUNA® with 2.5g prebiotics can help. The new LUNA with 2.5g prebiotics combines sweet, tart and fruity flavors with prebiotic fiber, to help promote digestive health.* Each bar contains 2.5 grams of prebiotic fiber, contributing to half of the recommended daily amount.

LUNA with 2.5g prebiotics has the same craveworthy taste and texture of the LUNA® you already know and love, but in new fruity flavors like Wild Cherry and Tangerine Zest™. Made with organic oats and no high fructose corn syrup or artificial flavors, LUNA with 2.5g prebiotics is gluten-free, delivers 8 grams of plant-based protein and is a good source of fiber.**

When you’re craving something sweet, trade those cookies for this fruity and refreshing better-for-you treat. LUNA with 2.5g prebiotics balances nutrition with mouthwatering flavors and textures for a feel-good snack break anytime, anywhere.

*Studies show that 5g or more of prebiotic fiber increases beneficial bacteria in the gut; this bar contributes 2.5g

**Contains 6-7 grams of total fat per serving.


  1. International Scientific Association for Probiotics and Prebiotics. Available at
  2. Holscher HD. Diet Affects the Gastrointestinal Microbiota and Health. J Acad Nutr Diet. 2020;120:495-499.
  3. Holscher HD. Dietary fiber and prebiotics and the gastrointestinal microbiota. gut microbes. 2017;8(2):172-184.
  4. Slavin J. Fiber and Prebiotics: Mechanisms and health benefits. Nutrients. 2013;5(4):1417–1435.
  5. Bonnema AL, Kolberg LW, Thomas W, Slavin JL. Gastrointestinal tolerance of chicory inulin products. J Am Diet Assoc. 2010;110(6):865-868.