A Primal Primer: Prebiotics

Probiotics get a ton of positive press from a multitude of sources (including here). It’s one of those areas of nutrition that receives approval from pretty much every camp out there, like fish oil. (Even Dean Ornish supports the usage of fish oil; just about the only type of fat he seems to approve of.) I’m firmly in the “For” column as well if you haven’t already guessed. I feel so strongly about probiotics and their integral role in gut and overall health that, as you may know, I’m coming out with a probiotic supplement in a few weeks. But there’s another aspect to the manipulation of beneficial gut flora. I briefly mentioned them last time, and today I’m going to really gut the whole beast, so to speak.

What Are Prebiotics?

Prebiotics are, quite simply, indigestible food ingredients that stimulate the growth and maintenance of beneficial gut microbiota. I suppose “indigestible by humans” is more accurate, because they are being digested – just not by our host digestive system (about 90% of prebiotic fiber makes it through the small intestine intact). Instead, it’s those oft-thankless, microbial workhorses of our colons doing all the work while we reap the benefits. They are getting free meals, so don’t feel too bad about putting them to work.

So you could say that prebiotics are food for your flora, those living organisms that contribute to our health and well being. For our intents and purposes, prebiotics are classified as soluble fiber. Conversely, insoluble fiber is the stuff that the human digestive system – neither host cells nor gut flora – cannot process nor digest, instead acting as a lubricant stimulant for our bowels (literally tearing our insides up, prompting the release of natural lubricant to speed up processing and limit damage). When most people discuss the so-called benefits of dietary fiber, they’re talking about insoluble fiber’s effect on stool passage and volume. Yeah, it speeds up the process and makes for bigger toilet paper bills. But I’m not interested in mere bulking agents. I’m interested in soluble fiber, in the type of fiber that our gut flora can actually consume and ferment. I’m talking inulin and oligofructose, along with fructooligosaccharides (FOS), galactooligosaccharides (GOS), and other oligosaccharides. Pectin, too, appears to have some prebiotic potential, but inulin and oligofructose are the big ones. Of course, all of these can be obtained by adhering to the Primal Blueprint Food Pyramid and eating a few servings of vegetables and fruits each day.

Researchers distinguish between long chain, short chain, and full spectrum prebiotics. Inulin is a long chain prebiotic fiber; long chain prebiotics contain 9-64 links per saccharide molecule and are digested more slowly, providing food for bacteria in the left side of the colon. Oligofructose is a short chain prebiotic, containing 2-8 links per saccharide molecule and fermenting in the right side of the colon, considerably faster. A full spectrum prebiotic supplement would be something like oligofructose-enriched inulin (OEI), which contains all possible saccharide links.

Historical Precedent

Prebiotic foods were certainly consumed by our ancestors, when and where they were available. The strongest evidence consists of cave deposits in North America in which remains of inulin-and-oligofructose-rich agave, sotol, wild onion, and camas bulbs have been found, along with massive cooking stones and vast (around twelve feet in diameter) ovens. Since similar cooking pits have been found the world over, from Australia to Europe, with some dating as far back as 30,000 years ago, it seems likely that these disparate sites were also used to roast the occasional fibrous tuber. None come with hard evidence of fibrous root or tuber remains, but that’s to be expected. Vegetable matter doesn’t last that long. We do know that wild roots, tubers, and other fibrous foods are available almost everywhere and that they are eaten where available by local populations. Take this account (PDF) of the Hadza of Central Tanzania, where the “tubers are continuously available throughout the year” and “all of their tubers have high fiber content.”  Or there’s the Maori, who used nearly every part of the cabbage tree, prized for its inulin content (which partially converts into fructose when steamed) and touted as a natural cure for colic, diarrhea, and other gastrointestinal disorders (maybe they were on to something?). If these types of fibrous, wild foods were widely eaten – and it seems likely that they were – early humans got a fair amount of prebiotic fiber in their diets.

In my opinion, one of the most compelling arguments for the importance of prebiotics in the human diet is the presence of galactooligosaccharides in human breast milk. Even the most ardent detractor of the viability of Paleolithic nutrition couldn’t deny that the macronutrients and micronutrients present in the only food specifically and expressly “designed” for human consumption – breast milk – are necessarily suitable for human consumption (unless there’s some creepy, nutty vegan extremist offshoot claiming breast milk promotes the suffering/subjugation of women and the consumption of too much dangerous saturated fat that I don’t know about). Breast milk contains both probiotics (bifidobacterium, mostly) and prebiotics for the bacteria to feed on. Since it’s in breast milk, there is a precedent for prebiotics in the human diet by design. I don’t think it’s a stretch to assume they can continue to have a role in the human adult diet.

What About the Health Benefits?

It’s all well and good to establish that prebiotic fiber was available to and even regularly consumed by many early human populations, but to build a case for inclusion in our modern diet requires some more recent evidence.

Dietary inulin and oligofructose increase fecal bifidobacteria.

Dietary inulin and oligofructose increase magnesium and calcium absorption. Most interestingly was the fact that calcium uptake apparently increases with inulin intake only when calcium intake is low or calcium requirement is high, suggesting a modulating (rather than blind) effect.

Prebiotics (inulin, oligofructose, and xylooligosaccharides) exhibited inhibitory effects on precancerous colon lesions in rats. Xylooligosaccharides increased gastrointestinal flora more than inulin and oligofructose, indicating possibly greater effectiveness.

An eight week regimen of 4g daily xylooligosaccharides reduced fasting glucose, HbA1c, oxLDL, LDL, and apolipoprotein B levels in Type 2 diabetes patients.

Prebiotics increase the production of short chain fatty acids in the human colon, including the supremely beneficial butyric acid, given a great summary by Stephan.

Galactooligosaccharides improved symptoms in patients with Irritable Bowel Syndrome.

Prebiotics combined with probiotics (called synbiotics) was more effective at gut modulation than either alone.

Matt Metzgar guesses that the supposed health benefits of whole grains stem from their prebiotic content, and that it was the widespread consumption of refined flour free of soluble fiber that made an already poor grain-based diet even more damaging. Sure, you could eat whole grains and get a bit of prebiotic fiber (along with loads of insoluble fiber, lectins, gluten, phytic acid and starch), but why go through the trouble when you could get even more from some crisp jicama sticks, Jerusalem artichoke, garlic, onion, or leeks with less effort, less roughage, and fewer antinutrients? To get the recommended six grams of inulin from chicory root, you’d have to eat a third of an ounce; to get the same six grams from whole wheat flour, you’d have to consume a quarter of a pound!

How Much Should We Be Consuming?

Jeff Leach, of PaleoBiotics Lab, recommends upwards of 135 g per day of prebiotic fiber, based on research into archaeological evidence from the Northern Mexican desert. That seems really extreme to me. I guess extreme conditions (“semi-arid region” with “limited rainfall and poor soil conditions”) necessitate extreme diets (“plant-based diet”). Those northern Chihuahans weren’t getting much dietary fat, so they probably had to rely on their gut flora to convert the prebiotic fiber into short chain fatty acids. That’s how the gorillas do it: they end up with a high-fat, moderate-protein, low-carb diet simply by consuming and fermenting an incredible amount of indigestible fibrous plant matter. We moderns have access to real animal fat and protein, so I doubt we need anywhere near 135 g of inulin and oligofructose.

I do think prebiotics are important. I’ve never really made a point of consuming them specifically (seeing as how I’m generally pretty down on fiber), but all my research on gut flora and probiotics leads me to believe soluble, prebiotic fiber (as opposed to insoluble fiber, the stuff seniors pop like candy, bran muffins, etc.) is actually quite important. Gut health is much more than just the small intestine. It’s almost as if there’s an entirely different digestive system playing out in the colon. The human colon may not be as robust and expansive as the gorilla colon, but it has the potential to do some damn fine work all the same – provided it gets the prebiotic fuel it needs. I suggest you provide that fuel by eating several servings of Primal prebiotic-rich foods each week, if only as a short experiment. Give it a couple weeks, at least until the sometimes explosive (but totally normal and expected) gaseous reactions subside, and monitor your digestive health.

What Foods Contain Prebiotics?

Let’s take a look at some more examples. In parentheses is the prebiotic fiber content by weight, followed by the amount of food required to obtain 6 g prebiotic fiber:

  • Raw chicory root (64.6%) – 1/3 oz
  • Raw Jerusalem artichoke (31.5%) – 3/4 oz
  • Raw dandelion greens (24.3%) – 1 oz
  • Raw garlic (17.5%) – 1.2 oz
  • Raw leek (11.7%) – 1.8 oz
  • Raw onion (8.6%) – 2.5 oz
  • Cooked onion (5%) – 1/4 lb, or 4 oz
  • Raw banana (1%) – 1.3 lb

Inulin/oligofructose content (per 100g raw)

  • Chicory root – 41.6 g/22.9 g
  • Jerusalem artichoke – 18 g/13.5 g
  • Dandelion greens – 13.5 g/10.8 g
  • Garlic – 12.5 g/5 g
  • Leek – 6.5 g/5.2 g
  • Asparagus – 2.5 g/2.5 g
  • Banana – 0.5 g/0.5 g

Inulin content is altered by cooking, but not a lot; some of it is even converted into fructose (that’s how agave nectar is made, in fact). As Jeff Leach shows, traditional-style oven roasted chicory root (356 degrees F) lost about 10-20% of its inulin content, while cooked/fried onions lost only 10%. It’s safe to assume that cooking will preserve most of the prebiotic fiber in other foods, too.

As for getting all the other prebiotics researchers are beginning to explore through whole foods, it isn’t clear how available, say, xylooligosaccharides are in the context of a normal Primal eating plan. From what I can see, most of the newer, more obscure prebiotic supplements are obtained by processing oats or corn or some other cheap, readily available food source. They undoubtedly occur in other veggies, too, but it probably doesn’t make financial sense to reduce several dozen tons of broccoli or asparagus when you could just as easily process a bunch of cheap grains. Supplementation seems pretty safe all around, especially in the context of a probiotic-rich diet. On the other hand, sticking with the Primal Blueprint Food Pyramid and eating a variety of fresh vegetables (leafy greens like kale, chard, and spinach, as well as broccoli, cauliflower, and any other vegetable that contains soluble fiber) will get you plenty of soluble, prebiotic fiber in all its forms and is definitely safe.

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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114 thoughts on “A Primal Primer: Prebiotics”

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  1. I put onion and garlic in almost everything I cook. Looks like I’m on the right track and didn’t even know it. I don’t know about dandelion greens though, maybe I will give it a shot. Great post Mark, thanks.

    1. Fish oil, garlic, onions, milk (of any animal, in any form), and many other foods talked about in this discussion are harmful to humans.

      1. Eating any food at all is not healthy. In fact, most humans are already dead and don’t even know it. Kind of like The Sixth Sense.

        Just remember to be afraid to eat anything.

  2. Great topic! I love the rough treatment you give grains as a fiber source, and promote real foods like fruits and vegetables instead. I bet sea weed and its ilk have lots of soluble fiber, too. Even more reason to try my egg and kombu soup.

  3. I’m sorry to say, but if we ate the amount of garlic, leeks, and onions that we need to get 135 grams of prebiotics, we won’t have any friends left. Are there any other vegetables or even fruits that we can eat that aren’t on the list? Is the list really that short?

    1. I think the lesson is, a lot of the delicious things we already eat or use in primal cooking have even more benefits than taste. Just keep eating a wide variety of natural foods and you’ll reap all the benefits.

      I think the effort vs. reward of purposely going out of your way to include or meet some ideal intake of most of the good things we discover in food skews heavily toward the “effort” part of the scale – very few things are worth paying such specific attention to unless you know you’re deficient. KSS and just eat primal and you’ll be ok!

    2. Yeah a pound of onion a day. I guess you could slice up a 1 lb Maui onion, dip it in a little omega 3 organic eggwash and coat it with almond flour before frying it in coconut oil. That sounds like a diet item I could choke down.

      I’m dubbing that Grol’s Prebiotic Onion Rings. Pictures forthcoming.

    3. That is so true and funny. Especially in conjunction with the fat intake.

    4. I don’t want friends; i want perfect health and longevity. Besides, i prefer the company of animals anyway. So far, so good. Seriously, i eat a lot of raw garlic, plus lots more minced and granulated garlic and onion, but don’t reek of it thanks to the enormous amount of chlorophyll i also consume.

    5. Extremely healthy sources of prebiotic soluble fiber include mucilage soluble fiber (from psyllium husk), glucomannan soluble fiber (from shirataki noodles, konnyaku cubes, or sukiyaki), galactomannan soluble fiber (from natto, edamame, TSP, TVP, guar gum, or carob bean gum), beta-glucan soluble fiber (from oats or mushrooms), and fructooligosaccharide soluble fiber (from onions, garlic, or bananas), which is also known as FOS. Pectin soluble fiber (from apples) contains a small amount of arsenic. Insoluble fiber (from wheat bran) has been shown to prevent cancer as well as psyllium husk and much better than oats or oat bran.

    6. oh, you actually will have a lot of friends… that also eat that amount of garlic, leeks and onions…

    7. Funny remark! I love garlic so much but it sure will not win you friends if you eat too much. Great article though and not much I didn’t know about the foods that are healthy but did learn as to “why” which is nice to know. I love common sense and will be a fan because of this article. Thank you!

    8. On the other hand if everyone ate them, or if only your friends ate them it wouldn’t matter.

  4. I have been drinking Raw milk for thelast few months and prebiotics and all that good stuff is just one benefit from drinking farm fresh milk. I feel great.

    1. I used to LOVE milk. I would drink up to 6 glasses a day… no joke. This was pastuerized, crap cows milk of course. I learned my lesson and stopped drinking it because of the strong link to acne.

      I have not drank pasteurized cows milk for about 5 months now.

      But, I have recently been interested in raw grass fed milk. I have experimented with raw grass fed cheese and love the flavor. I may try some milk when I go to my first farm visit soon.

      Mark do you know the content of prebiotics in raw milk?

      1. You can Google raw milk and get some good info about it. Also google raw goat milk. It’s different and I’d say better than cow’s milk. I’ve done both and prefer the goat.

    2. Totally agree with you! I’ve been drinking raw milk for quite some time and would never give it up. It’s great stuff.

  5. Love garlic and onion, but they give me gas, so I can’t eat them.

    1. The Gas would be your gut flora adjusting to eating the prebiotics…In extreme cases it can take up to 2 weeks for them to adjust but usually its much faster.

    2. If you cut the ends off of garlic cloves it will cut down on the gas factor. I am not sure why, but I knew a cook once that taught me this trick.

      1. nuke garlic cloves for 3-4 minutes and it will destroy the enzymes that give off the strong odor. Don’t know if that neutralizes the beneficial components, but most people cook garlic anyway, unless you are fermenting it.

    3. That gas is a sign that it is working, I find the more gas the foods give me the better they are working for my system. I think some foods work better than others for each individual.

      1. I don’t know that I buy this idea that gas means the prebiotics are working. I’ve had gas ALL MY LIFE from FODMAPS, esp onions, cauliflower, broccoli, and garlic. It has never gone away. All my cousins on one side of the family have the same digestive issues. Would be amazing to be able to eat onions without the repercussions.

        1. Hi,

          sounds like you may have an underlying digestive issue like a form of SIBO or a parasite/ Candida etc which is causing your reactions to FODMAPS. That type of gas isn’t normal at all. It’s worth doing some extensive stool testing to get to the bottom of it as digestive trouble is only the tip of the iceberg in terms of issues this type of infection can cause. Once you’ve established the root cause you can then work out the best way to treat it and then re populate with beneficial bacteria and feed it with pre and probiotics that work best for your microbial make up as everyone is different. I’m speaking from experience as I had H.Pylori and am now diagnosing what bacteria is causing my SIBO. I now have Celiac and Histamine intolerance which I am sure is as a result of being fobbed of by doctors telling me it was only IBS for years. Good luck!

        2. Wow! I totally agree! I think there needs to be some mention in the article where PREBIOTICS may be contraindicated. As in SIBO or the wrong gut flora! Be careful when supplementing with PREBIOTICS if you are NOT sure if you have any of these conditions! I am surprised Mark didn’t mention that in this article?!

  6. Thank you for the great post, I was looking for a clear distinction betw. probiotics and prebiotics and fresh skeptical look at their benefits!

  7. What about Jicama, Mark? Prebiotic fiber/inulin-oligofuctose content?

    …and where do fermented foods fit in the context of those numbers?

  8. From Wikipedia: Despite its name, the Jerusalem artichoke has no relation to Jerusalem, and it is not a type of artichoke, even though both are members of the daisy family.

    (In case anyone else was wondering whether their artichokes came from Jerusalem.)

    1. Al, if artichokes and Jerusalem artichokes are in the daisy family … they ARE related by virtue of being in the same ‘family’

      1. That is pretty much like saying all plants are related because they are in the plant kingdom. In fact there are well over 20,000 plants in Family Asteraceae or Compositae which it is called in my edition of Flora of the Pacific Northwest (1973). Called aster family because most likely there are more plants in the aster genus Asterae than in the daisy genus Erigeron although daisy family is also used. Artichokes are a cultivated variety of cardoons while Jerusalem artichokes are a species of sunflower. Other plants in the family are: Ragweed, Chamomile, Burdock, Sagebrush, Wormwood (absinthe), Thistle and Chrysanthemum to name some of the more common ones.

  9. Where does yogurt, kifer and the like work into this discussion? Probiotics (pre too?) are foundational to the marketing of those products. I’ve always wondered if those lactobacilli or whatever made a safe trip through the stomach to the healthy bacteria colonies. I guess mother’s milk delivers so no reason yogurt couldn’t.

  10. interesting post…more reason to use my garlic and onions… cooked in cultured butta for the butyric acid!

  11. to bust your bubble, there are vegan extremists who abstain from both breastfeeding AND oral sex. i wish i was kidding.

  12. “…third of an ounce; to get the same six grams from whole wheat flour, you’d have to consume a quarter of a pound!”

    But, how many ounces is a quarter of a pound? Hm… A quarter of a pound is 4 ounces. That’s 12 times the first amount! Okay…

    Nice word choice there, Mark. 😉

    1. Yep — was just reading about burdock root and FOS…Also, dandelion root… Burdock, of course, is used more in cooking — Asiatic cuisines mostly… I used to sautee some burdock in with veggies… And, it’s a powerful tonic for the Spring/liver (Traditional Chinese Medicine)…so, right now is a good time of year for this plant (I’m posting this reply in late April 2012, btw).

      Lastly, quinoa is very high protein grain (from the Andes) AND also contains prebiotics.

  13. Glad to see banana on the short list. Since going primal I have limited my fruit consumption. I mainly consume berries (strawberries, blackberries, blueberries, raspberries, goji berries mainly), banana, and apples.

    While a banana has a lot of sugar – it sure does taste wonderful and is perfect for smoothies as it gives them the perfect texture. I won’t be gorging on bananas now, but I will enjoy them with less guilt because of the little prebiotic content.

  14. I read somewhere (can’t remember where) that prebiotics should be avoided for people who have unhealthy gut flora because they feed the good as well as the bad bacteria.

    1. That doesn’t make sense. You’d be starving the good along with the bad. I would say increase the number of good flora with probiotics and feed them with prebiotics.

    2. Rather I’ve read it’s the other way round – good fiber promotes good gut microbes and discourages the bad guys – which makes more sense.

    3. I think the key with that is where the overgrowth of the bacteria lies. If you have SIBO then it may well be ‘good’ bacteria that is overgrown but because it is in the wrong place the small intestine it has no benefits and causes damage. Also any thing that feeds the good bacteria in the large intestine would also feed the good overgrown bacteria in the small intestine and make the problem worse. If it’s a case of dysbiosis in the large intestine then it should be fine as the good bacteria (pro biotics) will crowd out the bad and the pre biotics will also feed the good bacteria.

  15. Here in Denmark we can buy fermented dandelion juice with a high content of inulin. It has been sold for many years as a remedy against arthritis.
    I wont advertize as we are asked not to, and I suppose you have something similar on the market in America.

    1. Cold you please send me a private message with the brand name? I live in Norway.

  16. woohoo!

    Chicory root – 41.6 g/22.9 g <3
    Dandelion greens – 13.5 g/10.8 g <3
    Garlic – 12.5 g/5 g <3
    Leek – 6.5 g/5.2 g <3 but hard to get in Germany
    Asparagus – 2.5 g/2.5 g <3

    thanks mark!

    1. leeks hard to find in germany? really? at least where i am (south western corner), i’ve never been to a grocery store without seeing a leek (“lauch” or “porree”)

  17. Um yeah I’m going to disagree with this post. Inulin is only digestible in the colon, and as a result produces a lot of gas, cramping and bad bowel movements. I.e., inulin sucks. Anyone who has eaten Jerusalem artichokes can attest to this.

    1. Maybe there is something in Jerusalem artichokes that bothers you. Inulin is in lots of things and your body needs it to be healthy.

    2. That is the whole purpose of this article and eating these foods. If you get used to eating them it is not painful. To the contrary, I think artichokes are the best things to regulate the system.

      1. Re your comment: “…To the contrary, I think artichokes are the best things…” Are you referring to “artichokes” or “Jerusalem artichokes”, which are two very different things.

  18. Hi everyone, Just one question: what do you think about Psyllium and Glucomannan?

  19. nice to see this topic, I was wondering about this subject. As a person with GI issues from food allergies,at my worst a dr. recommended probiotics…this was in combination with another med, but the results were positvie results. I havent had issues again until recently when eating out (am allergic to beef and this place marinated and cooked my lamb in beef juices, who knew to ask right?) since then I’ve had a hard time recovering so I’m restarting on some probiotics.

    My question is, take these long term or take until my gut quiets back down? I’m living overseas so good medical care isnt always possible, so I’m trying to do what I can on my own until its time to fly home for some advice.

    I’ve been primal for over 2 months now, -15lbs without much effort. Love this way of life but sometimes the outside world doesn’t understand about cross contamination of food!

    would love to hear what your thoughts on the above question….

    1. I rather doubt you’re allergic to beef itself, just grain-fed beef, which is likely all you’ll get in a restaurant. Try 100% grass-fed beef, as close to raw as you can stand.

  20. Great post! Everything regarding gut health – fiber, prebiotics, probiotics – is still very confusing to me, so any illumination like this is so helpful. I’m starting to grasp the nuance of gut health (which helps me explain my diet better to friends).

    I found it really interesting to note that raw garlic is a great prebiotic, while fresh, full-fat yogurt is a great probiotic, because in Greek Tzatziki sauce, which is yogurt-based, raw garlic is one of the main flavoring agents. Looks like there is a lot more going on there than just great flavor.

    I think I’ll whip up a batch of delicious Tzatziki tonight, give my gut flora a boost 🙂

    1. it’s interesting how we keep stumbling on the health benefits of traditional diets. much more effective than the use of things like inulin powder, which some people do not tolerate well. kimchi for gut health. sauerkraut too!

  21. The average western diet only contains around 2 – 4 grams for soluble prebiotic fiber daily. Current belief is that to achieve the prebiotic effect no less than 8 grams and as much as 16 grams must be consumed daily. This is very difficult in our modern life style. Almost everyone would benefit greatly from prebiotic supplementation. Prebiotin is one of the few dietary supplement that contains a generous mix of both inulin and Oligofructose which makes it a full-spectrum prebiotic and nourishes the good bacteria in the entire large intestine.

    1. I talked to a nutritionist who recommended 45 grams (which, she said, was about a third of the highest recommendations)! That’s a lot of veggies and … gasp… beans.

  22. Jessica is correct. For people with chronic digestive problems and a long list of other health problems, some doctors, NDs, and nutritionist recommend the GAPS diet, which eliminates all starches and many other foods that contain FOS, inulin, and related compounds. The aim is to heal the gut lining, reduce gut inflammation, and promote healing.

    Many people experience ongoing gas and bloating from FOS in supplements and in foods rich in them; it’s not necessarily something that clears up after a couple of weeks of eating those foods. People appear to vary widely in their digestive strength and toleration of many foods.

    1. So, what you are saying…is that someone with IBS, for example — probably would need to be on the GAPS diet for some time to heal their gut…and then eventually transition back into eating more of a diversity of whole foods?

    2. With respect to what your saying, I think it’s bad advice. Prebiotics feed bacteria, some good and bad it’s true, but to avoid digesting them will only weaken an already weakened immune system. I have Ulcerative Colitis and bacterial dysbiosis. Prebiotic consumption is one of the few things my body can tolerate at all- because it’s so very needed. Of course I can only relay my own experiences, but still I feel strongly about it.

      In addition it’s taken me a very long time to see the benefits, change like this takes a long time and happens very slowly, but it’s worth the effort. If I knew then what I know know… So many choices could have been avoided.

      1. Just to clarify, the only two prebiotic foods that are not allowable on the Specific Carbohydrate Diet (which the GAPS diet is based upon) are chicory root and Jerusalem artichokes. All of the other ones are perfectly fine.

        The whole idea behind the SCD/GAPS philosophy is to starve out the “bad” bacteria by eliminating the types of carbs that feed them. It’s meant to be used as a temporary healing protocol, not as a lifelong way of eating.

        While my daughter reversed most of her digestive symptoms with it within weeks (which saved her from harsh prescription drugs), over time, it was all too easy to overemphasize nuts and honey, and she ended up with an almond intolerance. So, she and I are now Paleo, which presents its own challenges as well, as any restrictive diet does.

        We all have to do our own research and connect the dots of different philosophies so we can create our own, personalized recipe for digestive health and overall wellness. Having researched and implemented many different naturally gluten free nutritional theories, I can tell you that individuality must be taken into account, as no one diet can work for everyone.

        Anyone with a serious digestive illness would benefit from reading a wide variety of high quality literature, such as Elaine Gottschall’s Breaking the Vicious Cycle: Intestinal Health Through Diet, Dr. Natasha Campbell McBride’s Gut and Psychology Syndrome, Drs. Sydney V. and Merrill P. Haas’ Management of Celiac Disease, and for a slightly different perspective, The Maker’s Diet, by Jordan Rubin.

        Healthy eating and avid reading go hand-in-hand! Have a healthy, happy day.

        1. I think the key with that is where the overgrowth of the bacteria lies. If you have SIBO then it may well be ‘good’ bacteria that is overgrown but because it is in the wrong place the small intestine it has no benefits and causes damage. Also any thing that feeds the good bacteria in the large intestine would also feed the good overgrown bacteria in the small intestine and make the problem worse. If it’s a case of dysbiosis in the large intestine then it should be fine as the good bacteria (pro biotics) will crowd out the bad and the pre biotics will also feed the good bacteria.

  23. I believe that even cooked chicory and dandelion root contain some pre-biotics. A great coffee alternative w/out caffeine is a coffe-like drink made from brewed roasted chicory root and dandelion root granules (sold online by Frontier Co operative; health food stores can special order it).

    Another option is a product called Teeccino. (While it contains barley; the gluten does not extract into the liquid. The product is certified gluten-free).

    Both products tastes best and come out more rich, robust, and dark prepared in a percolator or boiled in a pot, then strained. A drip coffee maker does not work. The Garden of Eating Cookbook and the Ice Dream Cookbook include brewing tips that surpass what you find on the packages for these products.

    An instant product made from those roots is DandyBlend (it is gluten free; the rye used to make it does not extract into the liquid that is freeze dried).

    1. Teeccino is not gluten free. I thought it was and suffered a terrible reaction to it.

  24. Hey Mark!

    My holistic allergist put me on a flax seed/probiotic supplement regiment for a month to clear an internal fungal infection that was causing dermatitis around my mouth. Among other things I’ve been using in conjunction, I’m almost completely healed.

    I had no idea flax seeds were prebiotics, but it’s good to know even the foods I consume a lot of anyway (onions, garlic) in my cooking is helping.

    And as a woman, consuming flax on a regular basis has really helped with my sometimes wacky, almost-always bitchy monthly visitor!

    1. Curious how you are consuming the flax seed – ground as meal in salads and smoothies, or mostly in this supplement? I’ve been using a lot more lately, but always looking for ways to bring it into the diet more.

  25. Hi Wacky Jackie….love the handle, lol

    I grind flax seed before adding it to smoothies. I’ve actually just cut it out, because my suspicions have led me to believe I may actually have Leaky Gut syndrome. So I’m cutting out flax – for now

  26. I love flax seed. I grind up 3tbsp. Daily and add to almond milk. Some times with berry’s.

  27. Hello Mark,
    Thanks a lot for the article.

    I live in Canada and can not find fresh chicory roots here.

    What I found is roasted chicory or Radicchio in our supermarket.

    Do those contain inulin and if not, where can I buy the fresh one?

    Thank you!

  28. chicory is one our local wild flowers, so useful, handy and easy to process!! i grate the root into my foods for it’s blood strengthening properties, anti-cacer properties, digestions aid aspects. for those of you who ingest nitrites, it will also help clear your body of them. nitrites are used in curing meats. it is better to cure your own meat that you hunt yourself.

  29. please give me more easier instuction on prebiotic usages daily and how to measure daily use. i am a afro american. what are foods are good and effective now. is there a subplement for pre? what is the different between pre v pro?

    1. Probiotics are the gut bacteria that improve our health. Prebiotics is what they eat.

  30. What about konjac root? It’s been eaten in Japan for ages. Almost pure soluble fiber. Zero carbs. See for example konjacfoods.com.

  31. I go through quite a few konjac noodles. Konjac, a tuber, has even more soluble fiber then oats, and the noodles have zero carbs and zero calories. Also known as shiratake noodles in Japan.

  32. Hi Mark,

    One of your links to a clinical trial does not work. I get a “404 not found” message.

    It is the link to the study showing 4 g daily for 8weeks ingestion of xyologosaccharides reduce fasting blood glucose, HbA1c etc. in Type 2 diabetics.

    I would like to read that study, and learn the source of the prebiotic that they used.

    Thank you for this very interesting article, and the lists of food with the types of prebiotics..

  33. Help! I consumed 2bottles of milk beverage 2days ago coz I was so hungry after skul,am a college student about 2begin here project research nd am doin with dis lactose intolerance symtoms since den.I hvn’t gone anywhere since and as am typing dis am currently rolling around on ma bed.I hv tryed drinking lots of water,onion nd even oil.I need a quick remedy am soo uncomfortable and unhapi.help plz so I cn get on wif ma life and studies!

  34. great article – i came across your article doing research on c-diff. there are differencing opinions on probiotics but prebiotics are recommended.

  35. I had ready that the highest volume of prebiotics was contained in Gum Arabic, from the Acacia Tree. I make my own wheat free bread and use Gum Arabic (in place of the Xanthan Gum I formerly used) to act as a gluten replacer. The Xanthan Gum worked better, but I could not guarantee it was GMO free, since much Xanthan Gum is started with corn. Do you have any info on the type of prebiotic that Gum Arabic is? It would also be great to find a resource showing a wide range of prebiotic sources, and the type of prebiotic that they are. Thanks for the great work.

  36. Mark, I have a question! Ive read several of your articles covering this subject and you discussed the idea that antibiotics can kill off some of your good gut flora and that is when the bad stuff can take over.. I recently began a training program at a new gym and my trainer recommended an all natural supplement from the states (i live overseas) which would kill off the bad stuff. Combined with 2 probiotics, he said this would rebuild my gut flora and get me back on track. Ive been on this for the past few weeks and am committed to seeing it through. I am seeing great results.. Consistent trips to the bathroom at the same time every day (for the first time since i was a kid), but i am struggling with a feeling of nausea a few hours after i take the pills. Is this normal? Do you feel sick sometimes after you take probiotics? By evening time, when i should be starving, i open the fridge and feel like id rather vomit than eat anything. Sometime i eat some nuts or something and then i feel better and can eat dinner. Maybe my body is confusing hunger and nausea? What do you think? And then.. should i plan on taking probiotics forever? Or should i trust that my body will do its own thing once Ive finished the probiotics and my gut is on track?

    Thank you so much Mark! I read your stuff every day! Its a huge inspiration and help to me.

  37. hi mark

    cant say I agree with your conclusions re the pre-biotics. the evidence for eating whole grain wheat for Caucasians is at least 12,000 years old and I think we will find out that as our ancestors moved out of Africa (60,000+ years ago) they quickly adopted the use of the grains that grow in the middle east- wheat, rye, etc. Much easier to catch wheat which is stationary and which stores easily than a fast moving gazelle or sheep. Humans are basically lazy when it comes to food acquisition. If the genome project is right and we acquired the genes for our current ability to think about 100,000 years ago then we probably became sophisticated about our food habits long before McDonalds and the Paleo diet were thought about. I recently started consuming 6-8 servings of whole wheat foods daily with 13 probiotic species and no longer require immune suppressants for RA. I used to eat 5 servings of apple, orange, pears banana a day (none of which were available to my distant ancestors) and had lots of inflammation. Adding the wholewheat and pro-biotics has been transformative for me. I suppose that the books, supplements etc are a nice way of making money to buy the paleo food, without having to work at the 9-5 job and reflects the inherent laziness of our species when it comes finding food. Nothing like using the genes we all have! Watch out for snakes in the long grass when hunting your gazelle.

  38. I have gotten extreme heartburn for many years now from eating onions, garlic, leaks and bananas. What’s up? I so want to eat a healthy prebiotic diet and this is so disturbing! Help.

  39. Do regular canned artichoke hearts contain prebiotics or is it just jeresulaem? Wondering how the digestion of regular artichoke hearts plays out! is it more of a resistant starch?