What Are Prebiotics?

Prebiotics are non-digestible fibers, carbohydrates, and certain types of sugar that act as food for probiotic microorganisms that pass through the digestive system.

By eating prebiotics or taking a prebiotic supplement, you can improve the balance of microflora in your gut, which can encourage better overall health.

In this article, we’ll be discussing the difference between probiotics and prebiotics, natural sources of prebiotics, health benefits of prebiotics, prebiotic supplements, and types of prebiotic fiber so that you can get a better idea of whether they could improve your health.

What’s the Difference Between Probiotics and Prebiotics?

Probiotics are living microorganisms (either bacteria or yeast), that promote better health.

Prebiotics are foods (typically fiber) that provide a food source to probiotics.

What Foods are Prebiotics

Prebiotics in natural form come from a wide variety of plant foods.

If you’re looking to increase your intake of natural prebiotics, here are some of the prebiotic foods you can work into your diet:

  • Onions
  • Garlic
  • Bananas
  • Asparagus
  • Apples
  • Oats
  • Barley
  • Wheat bran
  • Seaweed
  • Flaxseed
  • Leeks
  • Jerusalem artichoke
  • Radishes
  • Carrots
  • Tomatoes
  • Yams
  • Cucumbers
  • Bell peppers
  • Sweet potatoes
  • Cabbage

This is by no means a comprehensive list of prebiotic foods. As you can see, there are a lot of options, so even the pickiest of eaters should have some prebiotic foods to work with.

Benefits of Prebiotics

The benefits of prebiotics come both from the prebiotic fiber itself and by being a food source for probiotics.

Some of the potential health benefits that prebiotics are thought to have include:

  • Improved digestion
  • Better colonic health
  • Better immune function
  • May lower risk factors for heart disease
  • Better nutrient absorption, including calcium, magnesium, and iron
  • Promotes satiety (the feeling of fullness after eating), which can help with weight management and obesity
  • Reduces inflammation
  • May protect against colon cancer (1)

Aside from the benefits you get from prebiotics being a fiber, you could make the case that prebiotics and probiotics share a lot of the same health benefits, because probiotics aren’t as effective without prebiotics.

Prebiotics and Probiotics Graphic

Prebiotic Supplements

If for whatever reason you don’t get enough prebiotic fiber in your regular diet, a prebiotic supplement can be a good option. That’s especially true if you combine it with probiotics.

Not all prebiotic supplements are the same, though. There are several types of prebiotics, which we’ll discuss in this section.

Types of Prebiotic Fiber

There are three main types of prebiotic fiber that both aid in digestion and provide a food source for probiotics: inulin, fructooligosaccharides, and galacto-oligosaccharides.

In this section, we explain these three types of prebiotics and why all of them are important.

Inulin

Inulin is a form of soluble prebiotic fiber. It’s found in a number of plants.

Inulin is low in calories and is good for digestion even just as a fiber. Inulin can be found as an ingredient in many fiber supplements.

Inulin is made up of fructose molecule chains that can’t be digested by the small intestine, also known as a fructan. This means that it travels undigested to the lower gut, where it acts as a food source for probiotic bacteria and yeast.

Some of the other health benefits thought to be associated with inulin include constipation relief (2), may have benefits in people with diabetes (3) (4) (5) (6), improves mineral absorption so it may strengthen bones (7) (8), it may be beneficial for inflammatory bowel disease (9), it may support heart health (10) (11) (12), and helps provide a healthy balance of the gut microflora.

Inulin does have some potential side effects that you should be aware of, although they are generally minor in nature. Those include: bloating, gas, and abdominal discomfort.

Fructo-Oligosaccharides

Fructooligosaccharides are a form of carbohydrate made of short fructose chains.

They’re also very high in dietary fiber content and are prebiotics.

Some sources of fructooligosaccharides include bananas, onions, garlic, yacon root, chicory root, leeks, asparagus, and Jerusalem artichokes.

Aside from being a great source of fiber, fructooligosaccharides may also decrease cholesterol levels (13), may fight against harmful bacteria (14), and of course, they’re prebiotic.

Galacto-Oligosaccharides

Galacto-oligosaccharides are prebiotics made up of plant-based sugars linked together in chain-like structures.

They’re non-digestible, and they provide a food source for probiotics.

Combined with probiotics, galacto-oligosaccharides ferment short-chain fatty acids and gases, “which is effective in genotoxicity, lowering cholesterol, improving infant health and efficient in diseases.” (15)

Sources of Prebiotics

There are various sources from which supplement manufacturers get prebiotics for their prebiotic supplement products.

It’s a good idea to get prebiotics from as many sources as you can. The reason being is that different types of fiber play different roles in digestion and also each probiotic strain has preferences as to which prebiotics they like to feed on.

If you’re getting prebiotics from food (which we should try to do as much as we can for optimal health), then you should aim for getting multiple types of prebiotics in your diet from a wide variety of food.

Likewise, when shopping for a prebiotic supplement, ideally you’d look for a supplement that contains several different types of fiber and prebiotics.

Chicory Root Powder

Chicory is a plant native to Eurasia, but has been transplanted to the United States and other parts of the world, where it grows freely.

Chicory root can be ground up and used to make a beverage that resembles and tastes similar to coffee, but without the caffeine.

Chicory root powder is a great source of prebiotics due to its high inulin content.

Gum Arabic Flour

Gum arabic (also known as acacia fiber) is a natural gum that comes from the acacia tree.

Gum arabic is very high in soluble fiber. It’s often found in powder fiber supplements because of this plus it doesn’t thicken so it’s easy to swallow, it has a smooth texture, and it doesn’t have an overly strong taste.

Because of its high soluble fiber content, gum arabic is a prebiotic and may help regulate blood sugar, lower cholesterol, and may even be beneficial in conditions such as diabetes and irritable bowel syndrome.

Lentils/Lentil Root Powder

Lentils have a high prebiotic carbohydrate content, so you may come across some prebiotic supplements that contain lentils or lentil extract as an ingredient.

Lentils are a good source of prebiotics, as they support “healthful hindgut microflora”. (16)

Conclusion

With all these different types of prebiotics, it’s important to keep in mind that you should try to get as many as you can. The reason being is that strains of probiotics tend to have certain prebiotics that they like and pair well with.

Whether you do that through foods or you get a little extra help from supplements is up to you, but getting a healthy amount of prebiotics will get you on track to having better digestive health—and that means better health overall.