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Prebiotics 101: Everything You Need To Know About Friendly Fibers

Posted by Brad Dennis, Ph.D. on

Prebiotics 101: Everything You Need To Know About Friendly Fibers

A healthy gut needs the proper balance of good and bad bacteria to keep us fit and strong.   This is the single most important part of our whole body health that we often neglect.   These bacteria contribute in a suprising variety of ways from helping with inflammation, cognitive health, as well as our digestive health.  In fact, up to 90% of our immune system resides in our guts.   But conversely, an imbalance of them puts our whole health in jeopardy, thus impairing both our digestive and immune system.  Luckily, prebiotics are there to prevent that.  Here’s a breakdown of prebiotics vs probiotics: everything you need to know about how they work and where to find them.

What Are Prebiotics?

In plain words, prebiotics are primarily dietary fibers that feed the friendly gut bacteria.
Though almost everyone now knows and uses probiotics, either as part of their regular diet or in the form of supplements, the general population is less informed about the health benefits of prebiotics.  In order to understand what they are and what effects they have on your health, you have to get familiar with fibers first.

By definition, dietary fibers are nutrients we get from plant foods that cannot be absorbed or digested by our organism. The same definition applies to prebiotics, although not every type of fiber is considered a prebiotic. Conversely, most prebiotics are considered dietary fibers because they behave as them, and therefore have similar effects.

Prebiotics as Friendly Fibers

What makes both dietary fibers and prebiotics so unique is their ability to travel down the upper part of your digestive tract and stay resist digestion by the normal digestive processes that typically break down and extract nutrients from food.   What separates prebiotic fiber from regular fiber, however, is that prebiotics act as food sources for the bacteria, selectively, in your guts and thus impart a health benefit different from non-prebiotic fiber.  Essentially, prebiotics are complex carbohydrates that nourish your gut bacteria, while dietary fibers consist of non-starch polysaccharides and oligosaccharides alike that don't selective feed your gut.  Prebiotics also come in different forms, such as polyphenols, however those are less frequent in our diets.

Prebiotic Vs Probiotic

But if prebiotics are in fact dietary fibers, then what is their relation to probiotics? Judging by the name, these two types of nutrients should have at least something in common, right?

Though specialists warn that the two shouldn’t be confused, they still have a lot of mutual characteristics. Probiotic, as you might already know, is considered a “good” or “friendly” bacteria that we add to our diets to help our gut flora restore proper balance. Good gut health and probiotics got hand-in-hand. Once digested, probiotics help these good bacteria grow anew.  

Similarly, but not quite, prebiotics are responsible for feeding the good bacteria that already resides inside of your gut and suppressing the bad ones.  As they pass down the small intestine, they are being fermented by the good bacteria along the digestive tracts, thus nourishing the gut flora to help restore or retain its balance.

In other words, where probiotics fail, prebiotics come to the rescue.

Why Are They Important?

When functioning properly, gut flora produces vitamins, performs metabolic functions and stimulates the immune system. This is ensured by good bacteria, but only if their number precedes the number of bad microorganisms that are part of the gut flora as well.  However, once damaged by poor dietary habits or antibiotics, good bacteria that share room with viruses and yeasts in the digestive tract need to be supplemented with prebiotics. 

Where Can You Find Them?

While natural sources of probiotics – yogurt and kefir, just to name the most recognizable ones – are well known to us all, rare are those who can name foods rich with prebiotics.  Luckily, plenty of those are already a part of our regular dietary choices, which means the chances are great that you’re already consuming the necessary amounts of this beneficial fiber without even realizing that you do.
Not that it’s surprising, but raw garlic makes the superfoods list when it comes to prebiotics as well. Banana is yet another common type of food that’s rich in these fibers, even though the same cannot be said about many fruits.  Like garlic, some types of foods are simply so healthy that you don’t have to guess that they include prebiotics as well.  Fibrous vegetables and fruits may act as superfood for your gut bacteria.  Other prebiotic foods fall under the category of nutrients not many people have heard of, let alone included into their daily menu. Chicory root, Jerusalem artichoke, raw dandelion greens, leeks and asparagus are all insanely beneficial, packed with prebiotics and surprisingly tasty as well.  Alternatively, they can be found in dietary supplements, like our Great Gut Extra-Strength Prebiotic Fiber , just like probiotics.

What Are Their Health Benefits?

Apart from the aforementioned effect on gut flora and certainly in connection with that, prebiotics serve many other purposes inside of our organisms. Improved digestion is a natural consequence of the role they play in the gastrointestinal tract, but it’s only one of their many benefits.

Like all other dietary fibers, prebiotics are dedicated custodians of cardiovascular health as they help reduce cholesterol levels and prevent heart-related diseases. Like both dietary fibers and some species of probiotics, prebiotics are quite effective when it comes to weight loss, thus contributing to our arduous battle against obesity. They also effectively prevent inflammation and make bone structure sturdier, thus lowering the chances for osteoporosis and fractures.

Gut flora has a central part in our bodily functions, and by keeping it safe, prebiotics ensure better hormonal balance and improved immune system too – either directly or indirectly, simply put, prebiotics protect both physical and mental health.


Probiotics, prebiotics, and synbiotics—approaching a definition
Dietary modulation of the human colonic microbiota: updating the concept of prebiotics
Gastrointestinal effects of prebiotics


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