Most of us are familiar with the health benefits of probiotics, but prebiotics—the indigestible fibers that provide food for their probiotic cousins—are an often-under-appreciated nutritional powerhouse.

Today’s post will give you a crash course on the health benefits of these unsung nutrient heroes including how you can get enjoy prebiotics with some of your favorite meals.

Prebiotic Basics—what they are, what they aren’t, and what they do

The term “prebiotic” was coined just thirteen years ago. As mentioned above, prebiotics are specific indigestible fibers found in some (but not all) fruits and vegetables.

These fibers ferment in the large intestine, providing sustenance for good bacteria in your gut.

Good bacteria, also known as microflora, have been to play critical role in a wide variety of bodily functions, including:

  • Supporting your immune health1
  • Modulating your mood and emotional well-being through the gut-brain connection2
  • And contributing to the barrier that keeps pathogens and other unsavory invaders from entering your gastrointestinal tract3.

These beneficial microflora work hard to keep us healthy, therefore we want to keep them strong, diversified, and well nourished. Prebiotics do just that.

When it comes to describing the function of probiotics and prebiotics to patients, I love the analogy of a garden:

Think of your intestines as a garden bed, with probiotics as the seeds of good bacteria and prebiotics as their fertilizer. Put the them all together and you will have a healthy, diversified garden, consistently blooming with friendly bacteria. Conversely, if you plant your probiotic seeds without fertilizing them, you will wind up with far less diversity and much weaker plants.

Why prebiotics are such big business

The implications of prebiotics to long-term gut health are HUGE.

Whereas a few years ago you may have taken an acidophilus supplement to help restore gut balance with some success.

Now you add a prebiotic such FOS (fructoogliosaccharide) to that acidophilus supplement, and your gut has a far better chance to sustain and diversify good bacteria which leads to numerous health benefits.

Since this discovery, supplement companies and food companies have dramatically increased their advertising of the latest and greatest prebiotics in designer yogurts, fiber supplements, baby food, formula, and even pet food.

Are there different types of prebiotics?

Yes, but not every expert agrees on what type of fiber constitutes a prebiotic (more on this in a minute). According to published research from the University of Minnesota’s Department of Food Science and Nutrition, the following prebiotics have been proven to have beneficial effects on gut flora, with oligosaccharides being the most used/well-known:

  • Oligosaccharides including
    • Fructooligosaccharides (FOS)
    • Oligofructose (OF)
    • Galactooligosaccharides (GOS)
    • Transgalactooligosaccharides (TOS)
  • Inulin
  • Lactulose
  • Lafinose
  • Resistant starch (RS)4
  • Acai gum
  • Wheat dextrin
  • Psyllium
  • Polydextrose

You may not need to take a prebiotic supplement as you can include prebiotic-rich food in your daily diet. (If you are going to supplement with a prebiotic, consult with your health care professional to make sure you are getting a high-quality product that will be feeding your beneficial bacteria and increasing the diversity of your microbiome.)

 Naturally-rich food sources of these sought-after prebiotics include5,6,7:

  • Chicory root—chicory is rich in inulin, and is the most sought-after prebiotic by supplement companies. Chicory is also wonderful food for the liver and can be found at local farmer’s markets during the spring and summer.
  • Jerusalem Artichoke —a deliciously delicate tuber also known as the “sunchoke”. These resemble a potato more than an artichoke.
  • Soybeans—in their whole form, such as edamame or tempeh (a natural source of both probiotics and prebiotics). Look for organic, non-GMO soybeans.
  • Whole grain corn – Look for organic, non-GMO, preferably sprouted whole corn products.
  • Leeks
  • Onions
  • Garlic
  • Asparagus—be sure to consume asparagus in its whole state with fiber intact (strained, creamy soups don’t count).
  • Banana—bananas sometimes get a bad rap for being a sugary fruit, but they are also high in fiber, minerals, and gut-friendly prebiotics/resistant starch. Keep in mind, you will get more prebiotics if the banana is slightly green.
  • Whole grain corn—look for non-GMO, preferably organic please.
  • Breastmilk—this is obviously for the little ones only, but I thought it was just another great example of why breastmilk is nature’s perfect food.

Other potential sources of food-based prebiotics:

Mushroom stems are also being studied as a potential source of prebiotics8, as is spirulina9—a blue-green algae often found in green superfoods.

Now, all this said there is discussion that ANY fiber has the potential to be prebiotic in nature.

There may be some truth in this, however, the current research shows us that for a fiber to be prebiotic in nature it must meet the following criteria10:

  • Resists gastric acidity, hydrolysis by mammalian enzymes, and absorption in the upper gastrointestinal tract.
  • Is fermented by the intestinal microflora.
  • Selectively stimulates the growth and/or activity of intestinal bacteria potentially associated with health and well-being.

Not all fiber works like this, so, for now, it’s best to stick to eating or supplementing with what we know works.

How do you know if you’re getting enough prebiotics from food?

I suggest speaking with your healthcare professional. Many patients benefit from extra probiotic and prebiotic supplementation during the initial healing phase, and can then rely on foods for for maintenance once gut balance returns and the healing process is complete.

It never ceases to amaze me how much we have yet to learn and discover about the healing nutrients contained within humble foods.

And with over 5000 known nutrients to explore (and more being discovered regularly), I look forward to sharing more hacks on how to get nutrients from everyday foods in upcoming posts.

Until then remember, food is—and always has been—your very best medicine.

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