Healthy Living on April 4, 2013 by

Getting Gastrointestinally Groovy: Prebiotics and Probiotics

It’s hard to miss the probiotic trend in the food industry these days. Probiotics are good bacteria that aid in the balance of our digestive tract. These microorganisms aid in digestion and support our immune system. They can help prevent intestinal upset and aid in the treatment of certain infections. In fact, if you’ve recently taken antibiotics, you’ve likely wiped out your good bacteria. Probiotics will help replenish your bacteria stash and get you back to your old self.

Prebiotics and Probiotics

These good bacteria are found in many packaged foods (everything from chocolate to protein bars to ice cream), but are naturally occurring in yogurt, kefir, kombucha, sauerkraut, miso, kimchi, and tempeh, to name a few. Notice that each of these foods is a fermented product. Fermentation is the result of active bacteria growth. To cause fermentation, bacteria is introduced to the food. This bacteria converts the foods sugars to acid, gas or alcohol. When ingesting these fermented foods, you add a live organism (more like millions of live organisms) into your digestive system. These organisms work to breakdown foods in your body and out-compete the bad bacteria that make us sick.

Probiotics are awesome, but they can’t work alone. That takes us to prebiotics. Prebiotics are the food that probiotics need in order to survive and get busy in your body. It makes sense, in order to out-compete the bad bacteria and thrive, these good bacteria need some fuel. Just like you combine sugar and water with yeast to activate it in order for your dough to rise, you need some kind of sugar to get these probiotics charging.

Not all sugars are created equal, however, so don’t grab a doughnut and think you’re helping out your kombucha with some fuel. The best prebiotics are whole grains, legumes and fruit, but other foods high in fiber are also good prebiotics. Fiber is key because it is the “waste” from your food that sticks around in your digestive system. This waste product is exactly what the bacteria need to thrive. Any food without fiber won’t offer up much of use to the good fauna in your system.

Prebiotics and Probiotics

Here are some great ways to combine prebiotics and probiotics for a healthy, happy digestive system.

  • Muesli and Yogurt– the ultimate in a healthy breakfast or snack. Pick yogurt that lists either Lactobacillus or Bifidobacterium in the ingredient list as a live culture. Choose a plain or vanilla flavor that is low in sugar for the most nutritious choice. Muesli is unsweetened, but contains dried fruit that will add a nice sweetness to your meal. The whole grains provide the prebiotic fiber and the nuts and seeds will give you an extra omega-3 bonus.
  • Brown Rice and Tempeh– combine a whole grain brown rice with tempeh for a one-two prebiotic/probiotic punch. Add vegetables sauteed in olive oil for a heart-healthy complete meal.
  • Whole Grain Crackers with Yogurt Dressing/Dip – Replace sour cream in your favorite dressing or dip with a probiotic-packed yogurt and pair with whole grain crackers, bread or even drizzle over a whole grain salad. Try this Creamy Avocado Yogurt Dressing from Mother Thyme and these Savory Hemp Crackers for a wonderful omega-3 rich snack.




Tim says:

Cassidy – I enjoy reading your blogs! I have a question for you concerning pre/pro-biotics (sort of).

I have been reading about the effects of Raw Potato Starch (RPS) when used as a source of Resistant Starch (RS).

When fed adequate amounts of RS, people’s gut bacteria thrive and many metabolic changes occur such as decreased absorption of cholesterol, lower fasting blood glucose, and better glucose control.

I have been taking 4TBS of Bob’s Red Mill Unmodified Potato Starch daily for several weeks, and have noticed an immediate lowering of fasting blood glucose from a high level (120) to a perfectly normal level (90).

In order to get the benefits of RS from RPS, the potato starch has to be ingested cold–not heated above 140 deg F. This allows the RPS to completely avoid digestion in the small intestine and arrive in the large intestine where it serves as food for beneficial gut bacteria.

I was wondering if you know the source of Bob’s Potato Starch and the manufacturing process used to make it?

If you would like to discuss resistant starch further, please contact me via email and I will send you studies and papers and discuss personal experience.


Hi Tim,

Our potato starch is made from starch potatoes using an extraction process. Starch potatoes are mechanically peeled and boiled then ground into a pulp. After grinding the potatoes and separating the fruit water from the potato pulp, the starch is extracted out of the potato pulp with tap water. The starch is then separated from the fibres by fine sieving.The extracted starch passes the fine sieve and fibres flow off the sieve. For more information, please contact our customer service team at 800-349-2173. Thanks!

Tim says:

You could make your company a lot of money if you marketed raw, unmodified potato starch as a form of RS (Resistant Starch).

Presently, the only commercially marketed RS is Hi-Maize corn starch, but it is only used in baking. Potato starch can simply be added to cold food like potato salad, smoothie drinks, and mixed with milk or other beverages. It must be consumed cold.

I’m curious in your description of your processing methods, you say they are peeled and boiled…it seems boiling at this stage would gelatinize the starch making it impossible to separate later…is this accurate?


This is the information we have from our supplier on the manufacturing process. Please contact our customer service team for more info. Thanks!

Tim says:

Thanks for your help! I got all the answers I needed from Customer Service.

For your info, Bob’s Red Mill Unmodified Potato Starch is manufactured in a way that makes it an EXCELLENT source of resistant starch. 2-4TBS a day, in a raw form (added to smoothie, potato salad, fruit salad, etc…) is an optimal amount for super gut health.

When you start hearing more about Resistant Starch in the future, remember this comment and pitch it to Bob–you’ll make money! People need a way to get a measured dose of RS easily–potato starch could be the ticket!

There’s not much out there in the way of Resistant Starch. Raw Potato Starch is 78% RS by-weight…that is huge!

See table 2 for other RS contents and info on the benefits of consuming RS.

Laura says:

Hi Tim or Cassidy,

I’m confused. I just spoke to customer service regarding Bob’s Red Mill Potato Starch and was told the potatoes were boiled/cooked as part of the process of making the potato starch they sell. This goes against the idea that Potato starch should be raw in order to have enough resistant starch as a pre-biotic supplement. Tim however, you say that customer service satisfied you that the BRM potato starch is processed in such a way as to maintain it’s high resistant starch content. Can either of you elaborate on either the process used to make the BRM potato starch or why it is a great source of pre-biotic resistant starch? Thanks for the help:)


Based on Tim’s answer, I think he means that you eat the starch raw- not that the potatoes are raw. So it should be a great source of resistant starch.

T.Nate says:


“I just spoke to customer service regarding Bob’s Red Mill Potato Starch and was told the potatoes were boiled/cooked as part of the process of making the potato starch they sell. This goes against the idea that Potato starch should be raw in order to have enough resistant starch as a pre-biotic supplement.”

When re-cooled, resistant starch returns to its original structure. The point of ingesting resistant starch cold is so that it bypasses digestion and absorption, allowing the beneficial gut flora (mainly bifido) to use it and multiply. This is why eating it after heating (e.g., adding it to a fresh up of coffee) defeats the purpose. You are consuming it immediately after applying heat. However, if you were to heat it up and then allow it to re-cool before consuming it, then there is no problem. This is why the manufacturing temperatures are not as important as the temperature PRIOR TO IMMEDIATE CONSUMPTION.

* ALL CAPS is not yelling. I am using it for emphasis.

Arganaut says:

I’m keenly interested in probiotics, and I read some time ago that Kefir is the best of them, because it has about 200 varieties of bacteria and fungi so if one of them doesn’t overwhelm the competition another will.

The only trouble is that raw milk here is priced out of the market, and the muck they sell as milk doesn’t qualify as milk to my mind. So I don’t have suitable milk to feed the Kefir.

RSF says:

I am casein intolerant so dairy (other than, thankfully, ghee) is off limits for me. I make water kefir to get the probiotics and bypass the dairy. This might work for you.

Ashwin Patel says:

Would it not be easier and cheaper to just eat a RAW potato that is high in Starch (Rooster). Or Maybe Juice it with other Vegetables such as Carrots and Beetroot to make it more potent and palatable? I drink this juice everyday and find it great.

Tara says:

Tim and Cassidy,
Since the potatoes are boiled before the starch is extracted, wouldn’t that dramatically reduce the amount of resistant starch in the final product?

Wouldn’t it be much higher in resistant starch if it was extracted from raw potatoes?


You’re delving out of our knowledge zone and we’re not sure what to tell you. Perhaps Tim can enlighten you.

samc says:

Potato flour is usually from cooked potatoes. Starch however is extracted mechanically and then wash out with water. I don’t think any cooking is involved. Take a look at some mfg company websites describing the process.

Brad Baker says:

Cassidy, along the same subject I think your Tapioca Flour product is confusing for consumers in how it is labelled… in that is used the term “starch” as if it is tapioca starch (ie, raw, unmodified by heat, fermentation, etc.). Tim (same guy as above) did some blood glucose tests after ingesting the Tapioca Flour in the same fashion as Bob’s Potato Starch and found the Tapioca Flour to create sharp spikes in BG which make me believe that it is indeed Tapioca FLOUR and not STARCH. I would recommend you guys exclude the word “starch” from the product to avoid confusion. Also, you guys might want to think about adding real (raw) cassava starch to your stable of products. Similar products are sold by other companies with a label similar to “Polvilho Doce” (sweet powder) and “amido de mandioca” (cassava starch). These are of the Brazilian Portuguese language but similar terms are used for Spanish labeled products. It seems to me only in the English language and America is (tapioca flour) and (tapioca starch) considered the same and the terms used interchangeably. In other countries there is a sharp distinction and for good reason, because the products are very different from how they are produced, their cooking properties, and how they are metabolized by the human digestive system. Sorry for the long post. To summarize…

On your website and product has the description “Tapioca flour, also known as tapioca starch”. This is absolutely incorrect in most countries where cassava in consumed.

More information on how the product is made would also be helpful. Eg. on your site it says the cassava is … “processed to remove toxins”. Explaining how it is processed would help a lot. Is it fermented? Is it heated?

Thanks for your time! cheers, -Brad-


Thank you for all of this information. I recommend calling our amazing customer service team for more info about how our Tapioca Starch is produced. They can be reached at 800-349-2173.

Brad Baker says:

Tara, I saw a post by Tim somewhere else that he was informed that Bob’s PS is produced by steaming the potatoes to clean them and remove the peel. This would not cook the interior or the potato and thereby retain the majority of the resistant starch content.

JM says:

Hi – just want to cast my vote from here in the UK to press you to market your unmodified potato starch as a source of resistant starch. I’ve just tried to obtain it here and there seems to be a supply problem – I agree that you could have a successful product and customers could have easier access to it if you considered going down that route. The UK retailer I just spoke to on the phone is having to refund 30 orders for it that she got in the last couple of weeks because she can’t get any more from the wholesaler.

MH says:

Hi there, just wanted to throw in my vote with JM for a steady supply of your unmodified potato starch over here in Europe. I am in Germany, and was importing it from the UK with hefty shipping costs, but as JM says, there is now a supply problem – I was one of the 30 orders that got refunded! I would love to have reliable source here in Germany.

Karen says:

Hoping that you will market an organic line of this product for those of us who prefer eating organic. Thanks.

Wayne says:

Adding my voice to those calling for a more sustained and regular supply here in the UK. It’s frustrating to not be able to buy this on a consistent basis when the benefits of consuming RS are becoming so well documented.

Ashwin Patel says:

In the UK you can buy Potato starch in any Asian/Indian Grocery store. Ask for FARINA Potato STARCH. Chinese food outlets also stock Potato Starch (used to thicken sauces)

shtove says:

I’m not sure farina in Asian stores is unmodified starch. Encona definitely was, but things seem to have changed in the past few months. Doesn’t help that their packaging has so little information.

Laurie T says:

An easy way to determine if a powder is pure starch or a flour (ground grain) is to check the amount of protein in the ingredients. Starch should have NO protein, while flour should have a few grams of protein and a couple grams of fiber as well.
I often have a problem interpreting recipes from Europe. example: corn flour vs. corm starch. You are never really sure what they are talking about. But if a recipe calls for a cup or two of corn starch… you can be sure it is flour.

Esther says:

I’m unsure of ‘Rakusen’s Farina potato flour’ is a good substitute for Bob’s until Bob’s is more readily available in the UK. It sinks to the bottom of a glass but the water is still a little cloudy. It has 0.1g protein. It’s available at Waitrose and Ocado. Any ideas? I hope Bob’s will be available here soon.

Bei der Laterne says:

In order to get resistant starch , could I not simply eat a cold cooked potato ? Potato salad maybe?

Zach says:

Is Tapioca Flour a Starch and would it be considered resistant starch?


Yes, tapioca flour is a starch, but it is not considered a resistant starch. Our potato starch, however, is considered resistant.

Dr. Thomas M. Wnorowski says:

Potato starch is a viable ingredient in gut health, but because potatoes may be sprayed with several chemicals throughout their lives, there is concern about residual toxicity in patients whose sensitivities are heightened by virtue of their conditions. Can you identify the biocides used in the management of the crop?

No, I’m sorry, we cannot.

Dr. Thomas M. Wnorowski says:

Is there a possibility that zero pesticides are employed?

No, this product is not organic. We cannot guarantee that no pesticides were used in the growing of the potatoes.

Francine Champagne says:

I just purchased Bob’s Red Mill unmodified Potato Starch. I was told it would help utilize the effects of the probiotic I take. I am confused how to use it and if it is beneficial as a prebiotic or probiotic aid?

I really am not sure, but I would guess that it functions as a prebiotic.

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