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5 Surprising Effects of Prebiotics

If you need to include prebiotics in your diet, here are some things you may experience.
FACT CHECKED BY Samantha Boesch

Probiotics are having a moment in the spotlight, and rightfully so. These live organisms have health benefits when consumed or applied to the body and can help the body keep the immune system in tip-top shape, keep gut health in check, and more—and who doesn't want that?

So, probiotics help keep us healthy. But, how do we help keep the probiotics healthy so they can do what they do best? Remember—probiotics are alive, so they need a bit of support in order to thrive.

And that is where prebiotics come into play. These indigestible fibers act as fuel for certain live bacteria, allowing them to selectively support beneficial bacteria while not fueling the not-so-great bacteria. So, even though prebiotic-rich foods like a slightly underripe banana, Jerusalem artichoke, and garlic don't have live bacteria, they can support your health by fueling those important probiotics that you took in via a serving of fermented food like sauerkraut, a helping of yogurt with added live and active cultures, or a probiotic supplement.

If you want to make sure you're getting enough prebiotics to support those probiotics, you should make a point to include some prebiotic-containing foods in your diet, especially if you are already making it a point to eat fermented foods and other probiotic-rich choices. Here are some examples:

  • Jerusalem artichokes, also known as sunchokes, are vegetables that are typically enjoyed cooked. They are a source of both soluble and insoluble fiber, and they are one of the most popular foods that people eat for a boost of prebiotics.
  • Garlic is naturally rich in inulin, a type of nondigestible carbohydrate that acts as a prebiotic. Research suggests that a component in garlic stimulates the growth of the beneficial type of bacteria called bifidobacteria.
  • Asparagus, like garlic, contains inulin fiber, which acts as a prebiotic. Adding asparagus to your diet may support gut health, as well as offer other potential benefits like reducing the risk of developing certain cancers.
  • Chicory root is a popular ingredient in many protein and granola bars, and is a natural source of prebiotics. As the root of the endive plant, this ingredient can also be used to make a coffee-like drink that is caffeine free.
  • Slightly underripe bananas. If you eat your banana when the skin has that tinge of green, know that you are getting a boost of prebiotic fiber when you enjoy your bites of fruit. Greener bananas contain resistant starch, which acts as a prebiotic in the body.
  • Supplements. If you find your diet missing many prebiotic-rich foods, a prebiotic supplement may be in order. Fortunately, many prebiotic supplements are available right on the supplement shelves at your local drug store or health food store.

So, if you are convinced that you need to include prebiotics in your diet (and we hope that you are), here are five surprising effects of prebiotics that you may experience.

Read on, and for more healthy eating tips check out The #1 Best Vegetable for Gut Health.

You may experience less inflammation.

body inflammation

Chronic inflammation is linked to various unpleasant outcomes, including developing diabetes and certain cancers, and certain heart disorders. Data shows that taking prebiotics may be linked to reduced inflammation, and some data shows that ingesting this fiber is associated with a reduced C-reactive protein, an indicator of inflammation.

You may have improved gut health.

gut health prebiotics

It shouldn't come as a surprise that taking in prebiotics can support gut health. As a means to maintain healthy gut microbiota, prebiotic fiber is an important factor in the gut health story. Remember—the human gut is an ecosystem comprised of trillions of microbes interacting with the host.

Prebiotic use can selectively increase or decrease specific intestinal bacteria that in turn, can promote gut health. For example, data shows that prebiotic use can encourage the growth of bifidobacterial strains, which are beneficial, while not encouraging the growth of the potentially harmful E. coli and Clostridium spp. strains that don't utilize the prebiotic fiber as fuel. Ultimately, this results in the gut having more beneficial bacteria and less potentially harmful bacteria.

Also, the beneficial bacteria that are fueled by the prebiotics may produce metabolites, like short-chain fatty acids, in the gut. These fatty acids improve gut health through a number of local effects, ranging from maintenance of intestinal barrier integrity, mucus production, and protection against inflammation. Some data suggest they are even linked to a reduction in the risk of colorectal cancer.

You may have better blood sugar control.

blood sugar control prebiotics

Believe it or not, the bacterial makeup in your gut can play an important role in type 2 and pre-diabetes management, specifically by modulating the inflammatory response, impacting glucose metabolism, and playing a role in insulin sensitivity. Unhealthy gut microbiota is linked to a decreased production of short-chain fatty acids, which is, in turn, linked to blood glucose management-related outcomes, like insulin resistance.

Taking in prebiotics can support the production of short-chain fatty acids, ultimately supporting blood glucose control. Of course, this would be only one small piece of the blood sugar-management puzzle, as dietary choices, medication compliance, and physical activity participation will play a significant role in your outcomes as well.

You may absorb calcium more effectively.


Prebiotic fibers have been shown to increase calcium absorption in clinical trials. Among the many results that have been shown when this relationship was evaluated, one noteworthy study published in the British Journal of Nutrition showed that treatment with prebiotic fiber increased calcium and magnesium absorption in postmenopausal women after 6 weeks.

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You may have enhanced immune health.

taking prebiotics

Selectively supporting beneficial bacteria, as prebiotics do, can prevent the colonization of pathogens, or potentially harmful bacteria. Plus, the beneficial bacteria can produce short-chain fatty acid metabolites that are beneficial for the human body in many ways, including having the ability to support the immune system.

When you are focused on keeping your body healthy during cold and flu season, along with taking your vitamin C and washing your hands, including prebiotics in your diet may help your body stay in fighting shape when you need the immune support the most.

Lauren Manaker MS, RDN, LD, CLEC
Lauren Manaker is an award-winning registered dietitian, book author, and recipe developer who has been in practice for almost 20 years. Read more about Lauren