You have probably heard about probiotics by now. But what are prebiotics?

Let me back up a bit to explain…

Probiotics explained.

Your body is made up of trillions of microbes. Most of these microbes live in your digestive system. Specifically in the last 5 feet of your digestive system, known as your large intestines or colon. These microbes are necessary for your survival. In fact, we live in a symbiotic relationship with them. We help them, they help us.

With that being said, the World Health Organization defines probiotic as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host (your body).” These probiotic microorganisms are provided through supplementation (powder or capsule) or fermented foodswhat are prebiotics

What are prebiotics?

Prebiotics are not microorganisms, but the food that you consume to feed the beneficial microorganisms.

To get more specific prebiotics are defined as “nondigestible food ingredients (fiber) that allow for positive changes to the composition of the microbes of the gastrointestinal tract.” In other words, prebiotics are specific types of fibers that allow the beneficial microorganisms of the gut thrive, reproduce, and provide benefits to you, the host.

Prebiotics are the “food fibers” that we eat that feed the live bacteria in our gut.

Some foods are better for feeding gut bacteria, such as fruits and vegetables with higher soluble fiber content.

The best prebiotic foods are foods high in fermentable soluble fiber. The three best types of soluble fiber to feed probiotics are resistant starches, inulin, and pectin. Here is a breakdown about each of these.

Resistant Starches

Resistant starches are plant-based foods that contain starch molecules that cannot be broken down. They have both soluble and insoluble fiber characteristics. Resistant starches are the best of both worlds for your gut.

Through bacterial fermentation in your gastrointestinal tract, resistant starches produce the most amount of butyric acid than any other soluble fiber type.

Butyric acid is a favored energy source for the cells of your large intestines. It stimulates the growth and differentiation of gut cells. Also, it stimulates gut secretions that produce antifungal, antiviral, and antibacterial compounds that naturally keep the gut healthy.

Other functions of butyric acid include electrolyte absorption, support of the immune system, and aid with naturally decreasing inflammation.

Foods highest in resistant starches

Foods with the highest amount of resistant starch are the following:

  • boiled and chilled potatoes (yep, cook and eat your potatoes cold)
  • green bananas (before they fully ripen)
  • barley (also contains gluten, so you should avoid if you are gluten sensitive)
  • oats
  • brown rice
  • beans and legumes

Inulin soluble fiber

Another type of soluble fiber that is highest in prebiotic qualities is inulin. Inulin is a prebiotic fiber that assists the body in the following ways:

  • lowers LDL cholesterol
  • keeps blood sugar stabilized
  • help keeps you fuller and longer
  • assists with bowel movements
  • increase and maintain good bacteria in the gut
  • may reduce the risk of colon cancer
Foods highest in inulin prebiotic fiber are:
  • asparagus
  • Burdock root
  • chicory root
  • dandelion greens
  • garlic
  • Jerusalem artichokes
  • leeks
  • onions and shallots
  • wild yams
  • bananas
  • jicama roots
  • stevia leafs
  • Brazilian ginseng (suma)
  • Dahlia roots


Pectin is a gel-like substance that is best known for it’s use in making jelly and jams. The bacteria’s diet in the gut favors the gel-like fiber. The benefits of pectin:

  • antioxidant
  • anti-tumor properties
  • enhances skin cells in the intestinal lining
  • decreases bacterial diseases in the gut
  • increases the diversity of flora in the gut
Foods that are high in pectin include:
  • apples
  • apricots
  • carrots
  • green beans
  • peaches
  • raspberries
  • tomatoes
  • potatoes
  • citrus peels
  • cherries
  • berries
  • winter squash
  • beans


Probiotics are the addition of actual microbes that support the microorganisms that already live in your digestive system.

Prebiotics are the foods that feed the beneficial microorganisms. Prebiotics are always a source of fiber, so  remember to increase your intake slowly.

There are various foods that can support a healthy digestive system. Start increasing the consumption of the ones you know and like first. Then you can explore others that sound interesting to you.

Also, keep in mind that these microorganisms produce gas as a byproduct. Increasing prebiotics may increase your gas production. Slow and steady wins the race with the addition of these foods.

What prebiotic foods to you know and like?




Leila is a wife and mom of two littles. She has a Masters of Science and is working toward completing a dietetic internship to become a registered dietitian. Leila has a enjoys using foods in their most natural form, along with herbs, to optimize the nutrients the body uses for day-to-day performance.