What Are Prebiotics For? [The Good, the Bad and the Balanced]




The connection between your gut and your health cannot be denied. Numerous studies have shown how your G.I. health affects things like immunity, memory and focus, energy, inflammation and overall health. Which is why it is important to maintain a healthy gut!

Most people are familiar with probiotics and all of the health benefits associated with them, especially in regards to G.I. health. However, many have not heard of or under-appreciate the benefits of and necessity for prebiotics. In order to permanently change distribution among the trillions of bacteria in our guts, probiotics are not good enough – prebiotics and prebiotic foods are needed.

So, what are prebiotics for? In this article, I am going to explain what prebiotics are, their benefits and uses, how they differ from probiotics, any safety precautions and the best way to get them in your diet!



What are prebiotics for

In the stomach, there are “good” and “bad” bacteria – constantly fighting for control of your microbiome! The balance of these organisms and not allowing the bad bacteria to over-grow is crucial to maintaining good health. One of the best ways to assist in maintaining this balance is by providing your body with an army of beneficial gut flora – including both probiotics and prebiotics. Both of which can be found naturally in most of the foods we eat. However, poor health and poor diet or restrictive diets can lead to needing supplementation.

Prebiotics are non-digestible plant fiber compounds in food that induce the growth or activity of beneficial microorganisms such as good bacteria and fungi, most commonly in the G.I. tract. These beneficial organisms help to fight disease and illness.

Fermentation is the main mechanism of action by which prebiotics are used by beneficial bacteria in the colon. Resistant to breakdown by stomach acid and enzymes, prebiotics are able to pass all the way through the G.I. tract unchanged where it can take root and stay for an extended period of time allowing the fermentation process to take place. When that happens, they cause the good bacteria to flourish and fight all the bad microbial.



What are prebiotics for


Probiotics are live “good” bacteria similar to the type already found in the digestive tract. When you take a probiotic, you are in essence sending in reinforcements to aid the beneficial bacteria already present. Keep in mind, however, that most probiotic supplements do not have the necessary amounts in general let a lone the viability needed to survive the acidic stomach and make a difference. That’s where prebiotics come in! (If you want to know more about probiotics and my top choice, head over to my article here)

“Prebiotics are food for probiotics”. Or another way to look at it is that they are like a fertilizer for the probiotics. Once these two interact, the good bacteria begin to rapidly grow, doubling in numbers about every twenty minutes, and increasing to counts far greater than any probiotic pill can deliver on its own.

Prebiotics are simple to use, unlike probiotics which are live organisms. In order to see any benefit from probiotic supplements, you have to make sure the probiotics continue to be viable. By comparison, prebiotics are complex carbohydrates and can be frozen or cooked and still retain their healthful properties.



What are prebiotics for



1. Reduces inflammation throughout the gut making it great for diseases such as IBD, IBS, ulcerative colitis or Chrohns.

2. Boosts immunity by feeding and promoting the growth of good bacteria

3. Aids in digestion by balancing gut flora which can in turn help with G.I. complications such as constipation or diarrhea and irregularity.

4. Increases the absorption of some vitamins and minerals such as calcium, magnesium. iron, zinc and copper.

5. Helps to reduce the risk of heart disease and lowers blood pressure.

6. Enhancing mucous secretion which is beneficial in protection against microbes and removal of toxins.

7. Promotion of satiety and weight loss and prevention of obesity




What are prebiotics for



There are thousands of different types of complex carbohydrates that feed our gut bacteria in fruit & vegetables, beans & whole grains. Although all prebiotics can be classed as fibers, not all fibers are prebiotic. They must meet specific criteria in order to be classified as a prebiotic such as: Resistance to digestion; Hydrolysis and fermentation by colonic microflora; Selective stimulation of growth of one or limited number of bacteria;  and Beneficial health effects to the host.

C/C Prebiotic fibers include:

Pectin, (found in fruit)

Inulin (found in onions, leeks, garlic & other foods)

Fructo-oligosaccharides or FOS (found in beans, honey, sugar beet, whole grains, rye and many types of fruit & vegetables such as Chicory root, Onions, Jerusalem artichoke, Garlic, Leeks, wheat, barley and Bananas)

Note: Also known as oligofructose or oligofructan

Galacto-oligosaccharides or GOS for short (these are long chains of sugar found in human and bovine milk)

Note: Also known as oligogalactosyllactose, oligogalactose, oligolactose or transgalactooligosaccharides (TOS)

Xylooligosaccharides (XOS) (found in bamboo shoots, fruits, vegetables, milk, and honey)

Raffinose oligosaccharides (found in seeds of legumes, lentils, peas, beans, chickpeas, and mustard)


Resistant starch is another type of prebiotic.

It’s a complex carbohydrate that forms when potatoes or rice are cooked and then cooled, which changes the sugars into longer chains. These long chains pass undigested to the large intestine, where gut bacteria break them down.

Potato Salad (cold, cooked potatoes) and Sushi Rice (cooked, cooled rice) are examples of foods that contain resistant starch.


When it comes to supplementation, clinical studies have shown there are only two official prebiotics, both of which are oligosaccharides. The two accepted prebiotics are fructo-oligosaccharide and galacto-oligosaccharide. Be aware,  there are other compounds that have “prebiotic-like effects” such as agave, dextrin,  lactulose/Lactilol (a lactose synthetic) and isomalto-oligosaccharide (a glucose carb vs. a fructose carb. It occurs naturally, in small quantities, in honey). Although, shown to have benefits just the same, when looking into supplementation, these are not the best prebiotic fiber sources to choose from. Stick with FOS or GOS.



What are prebiotics for


Eating a wide range of foods containing prebiotic fiber or complex carbohydrates will help a wide range of gut bacteria thrive in your large intestine. Different types of bacteria feed on different types of prebiotics, so eating a varied mix of prebiotics is key for a diverse microbiome.

In addition, eating a diet rich in prebiotics is ideal as some of the compounds produced during the fermentation process are also absorbed into the body and used in many vital interactions essential to overall health. I always stress how important getting nutrients from our diet is!

While there is no broad consensus on an ideal daily serving of prebiotics, recommendations typically range from 4 to 8 grams (0.14–0.28 oz) for general digestive health support, to 15 grams (0.53 oz) or more for those with active digestive disorders. Given an average 6 grams (0.21 oz) serving, below are the best (not the only) diet sources for prebiotics and the amounts required to achieve a daily serving of prebiotic fiber:

  • Raw Chicory Root – 9.3 g (0.33 oz)
  • Raw Jerusalem Artichoke – 19 g (0.67 oz)
  • Raw Dandelion Greens – 24.7 g (0.87 oz)
  • Raw Garlic – 34.3 g (1.21 oz)
  • Raw Leek – 51.3 g (1.81 oz)
  • Raw Onion – 69.8 g (2.46 oz)
  • Cooked Onion – 120 g (4.2 oz)
  • Raw Asparagus – 120 g (4.2 oz)
  • Raw Wheat Bran – 120 g (4.2 oz)
  • Whole Wheat Flour, Cooked – 125 g (4.4 oz)
  • Raw Banana – 600 g (1.3 lb)

Now, if eating like bugs bunny is not appealing to you – remember, it is possible to get it through other foods but may be difficult to reach your needed dosage depending on your current diet (I.e. poor diet or low-carb). Although, not as ideal as diet enrichment, there are supplements available to help you meet your daily dose!




What are prebiotics for


Not all prebiotic supplements, or their companies, are created equal. Always make sure you do your due diligence! There are reports highlighting potential dangers associated with supplements sourced from overseas countries such as China and Russia. However, just because a supplement is manufactured in the US, Canada or Europe does not mean it’s safe.

When researching a prebiotic company, look for the following:

  • A complete “About Us” or “Company Information” page on their website
  • A Board of Directors and/or staff with experts (such as medical doctors, PhDs, certified nutritionists, etc.).
  • A physical mailing address.
  • A working toll-free number that actually connects you with knowledgeable staff members.
  • The company uses Good Manufacturing Practice (GMP) standards


When looking for a quality prebiotic supplement, ensure the following:

  • Contains one of the two aforementioned accepted prebiotic strains GOS and FOS
  • Has a lot of positive reviews and feedback from the community (be sure this is found on a third party review site not selling or on many different platforms, i.e. not just amazon or the website itself)
  • Has a Money-back guarantee – standing behind their product
  • Has no recalls – making it more likely to be safe
  • Has a stamp of approval by an independent third-party tester. For example:




Always read the instructions on the product you are using and if unsure, consult a health care professional.

In general, prebiotics can be taken any time during the day. It’s good to remember that gas is often produced in the gut when gut bacteria ferment these fibers – Just like when eating prebiotic-rich foods like beans. It takes about 5-8 hours for these prebiotics to reach the colon, where the fermentation happens. So maybe the prebiotics should not be taken in the morning of an important evening event!

Prebiotics are best taken with probiotic foods or supplementation to enhance efficacy.




What are prebiotics for

Prebiotics have been designated as Generally Recognized as Safe (GRAS) by the Food and Drug Administration. They are commonly found in everyday foods and, for the most part, they are all-natural.

Prebiotics can lead to abdominal pain, bloating or flatulence if too many prebiotics are taken too fast. Reducing to lighter doses if these side effects occur and building up slowly is recommended. If you are taking supplements, consult the product information for an idea as to how much you should be taking. If you are not sure, ask your health care professional.

If you have a condition where you have overactive bacterial activity within your digestive system, prebiotics may not be helpful as they will only serve to stimulate further activity and discomfort. Always be sure to consult your health care professional before starting any new supplement to ensure it is right for you.

If you are taking a strong prebiotic, it is possible to get die-off reactions such as headaches or insomnia as the good bacteria displace the bad. Die-off reaction – also known as the Jarisch-Herxheimer reaction –  is believed to occur when injured or dead bacteria release their endotoxins into the blood and tissues faster than the body can comfortably handle it. This provokes a sudden and exaggerated inflammatory response which can cause a myriad of negative symptoms.

If die-off-reactions occur, it’s beneficial to either decrease dosage and/or try to take the prebiotics at different times of day and observe the responses to the varied timings. The afternoon may often be a good time to take the prebiotics so that you will be resting or sleeping at night when the prebiotics hit the colon and the good bacteria face off with the unwanted microbes.

If you are lactose intolerant or have dairy sensitivities, be aware that GOS is commercially produced through enzymatic conversion of lactose, from milk.




What are prebiotics for


Prebiotics provide many health benefits including the most notable – improvements to G.I. health.

A healthy gut is crucial to overall health. I always recommend getting your nutrients from your diet as best you can but when all else fails, a supplement can save the day! Just remember, not all products are created equal and be careful not to overdo it.

If you have any questions or want to share your thoughts on or experiences with prebiotics – please comment below!

Kind Regards,

Sherry S.


  1. https://academic.oup.com/jn/article/142/5/962/4630853
  2. https://www.ncbi.nlm.nih.gov/pubmed/17951495
  3. https://www.ncbi.nlm.nih.gov/pubmed/21992950/
  4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4124400/
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2812835/
  6. https://www.uofmhealth.org/health-library/hn-2847006#hn-2847006-uses

12 thoughts on “What Are Prebiotics For? [The Good, the Bad and the Balanced]”

  1. Hi there! Thank you for your comment. It looks like you got some good information from the article. I hope it proves beneficial in your pursuit for better health!

  2. Hi Sherry,

    I have read your article with lots of important information and guideline about “What Are Prebiotics For? – The Good, the Bad and the Balanced”

    I have read many kinds of articles on probiotics but not on prebiotics.Really this is an awesome article.I didn’t have any idea about prebiotics.After reading your article I understand that probiotics are great but they can’t work efficiently without prebiotics and they are very important for our health.It takes about 5-8 hours for its process.Thanks for sharing this informative article. 

  3. Hi there! Welcome to In Pursuit of Good Health – thanks for taking the time to read this article and comment! You are quite welcome for the article. 🙂 I am so happy you found i helpful and informative. I definitely hope others harness the power of prebiotics also! 

  4. Your own review and article on what Prebiotics are use for are really explicit and really loaded the right info needed. I have read online severally on Prebiotics but your article throw more light to its benefits. It great to know that it prevents the risk heart diseases and boosting immunity and regulating hormonal imbalances and some other great benefits. I think everyone should give it a trial. Thanks for sharing this article. 

  5. Hello Sue! I am so glad my article was insightful for you! I too at one point not too long ago didn’t know what prebiotics was. Knowledge is power! I am happy to share it 🙂

    I eat a lot of bananas myself but surely not enough – it’s definitely nice knowing I have reinforcements! 

  6. Hi Sherry, and may I express my appreciation for your very educational post. I have to admit that when I first saw the title, I thought Prebiotics was a misspelling. Was I in for a surprise! There are so many things that we are still learning about the way the human body functions. 

    Thanks for letting us in on the latest! Banana and onion is about the only ones I consume in raw form. It’s so good to know that there are supplements available to help with our digestion and all those mysterious bacteria that make it happen. Proper digestion is something that affects everyone’s health.


  7. HI there! Thanks for visiting and taking the time to comment! I am so glad you enjoyed the article and found it informative! Stay tuned for my top supplement recommendation :). 

  8. Great Content and Information!

    What a concise and thorough article. I found the post very detailed and Informative. So so many useful tips  all on one page! Wonderful! I bookmarked to look further. I have read series of articles on prebiotics but I can attest to the fact that this is the most comprehensive article I have ever read on this topic which has opened my eyes the more. Thanks for sharing this lovely tios

  9. Hello! I am glad you found the information in this article helpful! I have always advocated for probiotics but never really heard much about prebiotics so I definitely under-appreciated them! Now I make sure I get enough learning how important they are. 🙂

  10. I have read many articles on probiotics and very few on prebiotics. Thank you very much for sharing this valuable and detail information about prebiotics. I have some problems with my gut. For this reason, I always go through the articles on probiotics and its related topic. This article is injury much you so and helpful for me. it’s very kind of you for sharing and writing this topic.
    Thank you, Sherry!

  11. HI riaz! Thank you for visiting and taking the time to comment. During the process of fermentation you may experience gurgling in the stomach which is a sign they are working! This could also produce gas in the stomach which can present as belching. The majority of the fermentation takes place in the G.I tract (more specifically the large bowel) and can produce gas (just like any other dietary fiber) – which is usually presented as flatulence. Again, bloating, excessice gas or abdominal discomfort are usually signs you need to decrease your dosage. If that doesnt work, consult yout health care professional. Hope that helps! 

  12. Interesting article, I’m still putting the pieces back together on the probiotics and prebiotics thing. I understand that it takes about 5-8 hours for the fermentation process, what would happen during and after the process though? Since gas is created, will it be in the form of wind release maybe through burping?

Leave a Reply

Your email address will not be published. Required fields are marked *