Prebiotics: Feeding our Friendly Bacteria

Most people are familiar with probiotics – the trillions of good bacteria that live in and on us and keep us healthy.  The word probiotic literally means “for life”.  They are found primarily in the gut, in the mouth and on skin.  Without them we would not be able to survive.  Regard them with gratitude and respect!

Prebiotics, on the other hand, are specific forms of fiber found in foods that feed and promote the vitality of these resident beneficial microbes. Personally I think these are equally as important as probiotics and often overlooked in establishing a healthy population of resident bacteria in the digestive tract.

In total the trillions of microbes that live in us and on us weigh about 3 pounds – roughly the same weight as the human brain!

The Many Surprising Health Benefits of Probiotics 

First a few words about probiotics. Probiotics are often associated with digestive health. Your doctor might have suggested probiotic supplements after taking a course of antibiotics in order to restore your gut bacteria.  Some of the most common probiotic organisms found in supplements are species of Lactobacillus, Bifidobacteria and Saccharomyces. While probiotics are essential for digestive health, it is only a small part of the story of what these residents in our gut do for us.

Research in recent years has shown that our resident microbes are involved in far more aspects of our health.  Here are some conditions that studies have shown to be affected by the health and diversity of the microbes in our gut:

Probiotics are found in fermented foods such as sauerkraut, kimchee, fermented vegetables, yogurt and kefir.  As mentioned above probiotic supplements are often taken therapeutically.  Keep in mind, however, that while there are about 10,000 different species found in the gut, the typical high-quality supplement will only contain a maximum of about 14 or 15 different species. Although these are species important in health, the supplements cannot completely replicate the natural diversity that comes from a diet rich in food sources of these beneficial bacteria. Loss of diversity relates to increase risk for disease. Think food first!

Prebiotics to Keep the Beneficial Bacteria Happy

Prebiotic fiber is so essential to our health that it is found in human breast milk. Mother Nature knows what we need to thrive!

We should nourish our friendly bacteria just as they nourish us.  And here is where prebiotics come in – foods which contain the special forms of fiber which our beneficial bacteria need to survive.

Given that their average lifespan is about 20 minutes, think of the probiotic organisms as tourists passing through your gut. You want two things to happen. First, that they like the place they are visiting so much that they want to stick around to establish a permanent home.  Secondly, you want them to overwhelm any current “bad” local elements enough so that those harmful guys get crowded out. In order to do that you have to give them something to eat!  And what they thrive on is certain types of fiber found in food. While the harmful bacteria tend to favor sugar as their favorite fuel, the beneficial ones thrive on more complex carbohydrate molecules called oligosaccharides with names such as inulin, FOS, GOS and TOS.

Prebiotics In Food

Jerusalem artichokes a.k.a. sunchokes

Basically prebiotic fibers change the composition of the microbial community in the gut in a manner that favors the beneficial bacteria and compromises the potentially harmful bacteria.  Go for variety – different prebiotic foods feed on different strains of the good bacteria selectively.

Here are some superfoods which contain prebiotic fibers:

Asparagus  Raw is best, especially the tender tips. Have with a dip or dressed in salads. If cooked, lightly steamed provides the most fiber.

Jerusalem artichokes  Try raw slices in a salad or steamed like small potatoes – they have a delicious nutty flavor!  Don’t worry about peeling them as the thin skin is edible.

Dandelion greens  Use in smoothies, finely chopped in salads, or steamed/sautéed. Look for them in your lawn in the Spring!

Onions, Leeks and Garlic  Try to find ways to eat them raw when possible as the raw form contains almost twice as much of the prebiotic fiber. You’ll still get some of the good fiber in the cooked version.  See my post on garlic for more of its health benefits: http://www.foodwisdomnutrition.com/garlic-ancient-medicine-plus-a-tip-a-hack-and-a-recipe/

Globe Artichokes The hearts or bottoms are yummy additions to salads, blended for dips or lightly braised with olive oil and lemon.

Bananas Use less ripe ones for maximum prebiotic benefit.

Plantains As chips, boiled, sautéed, mashed, try using in place of potatoes.

Jicama The slices are great as chips with guacamole, in salads, or for a snack.

Raw wheat bran Add it to yogurt, cereal, baked goods or blended into smoothies.

Inulin fiber from chicory root is found in many processed foods, particularly fiber bars.

Fermented dairy Kefir and unsweetened traditional yogurt containing live organisms also contains some prebiotics. Yogurt and bananas – yum!

Other sources of prebiotic fiber

If you eat a variety of the above foods regularly, a healthy gut microbiome can be maintained. However, there are times in the course of a gut repair/restore protocol or if eating prebiotic foods is not possible, then supplementing with a prebiotic should be considered.

Prebiotic supplements. Try a powder or you might have to swallow a lot of pills. Look for formulas that contain both FOS and inulin at 2 – 4 g per serving. Here’s one from Garden of Life: http://www.gardenoflife.com/content/product/why-choose-doctor-formulated/dr-formulated-organic-fiber/

Synbiotics are probiotic supplements that also contain prebiotics.  I have not found one that contains enough prebiotic to reach anywhere near 2 – 4 g that is recommended for optimal gut health.  The idea with these small amounts of prebitoics in symbiotics might be to just give those healthy microbes a snack so that they survive long enough to make it to settle down in the lower gut.  Hopefully the fiber from prebiotic foods that you’ve eaten are waiting for them!

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