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Pre- and Probiotics for Your Health

There has been a lot of attention over the years surrounding prebiotics and probiotics. According to the National Health Interview Survey conducted in 2012, prebiotics or probiotics were the third most consumed dietary supplement apart from vitamins and minerals.1 Additionally, from 2007 - 2012, probiotic use amongst adults quadrupled and has undoubtedly only increased since then.1 So, the question is, do prebiotics and probiotics deserve the notoriety and fame they’ve received over the years? Do they live up to the hype? In this article, we will be exploring what prebiotics and probiotics are, where they can be found, and how effective they are in supporting health.

What are prebiotics and probiotics?

Although similar sounding, prebiotics and probiotics can bolster the human microbiome in different ways. It is, however, the balance between the two that bring about health in the body. Prebiotics are defined as “non-digestible food ingredients that beneficially [effect] the host by selectively stimulating the growth and or activity of one or a limited number of bacteria in the colon.”2 Simply put, prebiotics are a form of soluble fiber the body has a hard time digesting, making it the ideal “food” or “meal” for certain beneficial bacteria in the gut flora.3,4 Therefore, prebiotics can be considered the promoters of “good” bacteria.3

On the other hand, probiotics, as defined by the International Scientific Association for Probiotics and Prebiotics (ISAPP), “are live organisms that, when administered in adequate amounts, confer a health benefit on the host.”5 The term probiotics has often been used indiscriminately to describe all live organisms, when in fact the term should only be applied to microorganisms that have been studied and found to contribute positive health benefits.5 The live or active cultures found in probiotics can assist in restoring the balance of the gut microbiome by introducing “good” bacteria back into our bodies.3 Many microorganisms can be found in probiotics, but the most commonly used genera include Lactobacillus, Bifidobacterium, Bacillus, Streptococcus, Escherichia, Enterococcus, and Saccharomyces (yeast).6

Where can you find prebiotics and probiotics?

Prebiotics and probiotics can be found in a range of products, from different food ingredients to dietary supplements. Prebiotics are typically present in fiber-rich foods.4 Consequently, incorporating more fruits, vegetables, and whole grains into your diet can be a great way to increase prebiotic intake.3,4

The following is a list of foods containing prebiotics:

● Onions3

● Garlic3

● Beans3

● Asparagus3

● Leeks3

● Chicory root4

● Jerusalem artichokes4

● Bananas3

● Whole-grain foods3

It is important to note that prebiotics in dietary supplements are frequently not referred to as prebiotics.4 Instead, prebiotics can be listed on supplement labels as fructooligosaccharide (FOS), galactooligosaccharides (GOS), oligofructose (OF), inulin, or chicory fiber.3,4 According to the ISAPP 5 grams a day is the recommended amount of prebiotics to boost gut health.4

Probiotics can be obtained through several fermented food products, dietary supplementation, infant formula, medication, and even personal-care products (i.e., skin care).5 The following is a list of products containing probiotics:

● Aged cheese varieties (containing live cultures of Bifidobacteria and Lactobacilli)3

● Yogurt3

● Kefir3

● Sauerkraut3

● Kimchi3

● Miso3

● Tempeh3

● Kombucha7

● Pickles7

● Sourdough bread7

Even though many fermented products are excellent sources of probiotics, it is important to mention that many of them are labeled as containing “live and active cultures” rather than probiotics.8 This is due to the variability in microbial content in fermented products - from bacterial species and strain to the actual number of bacteria.8 The proper dosage of probiotics contained in food and supplements is “based solely upon the number of live organisms present in the product.”9 Interestingly, in clinical trials, a dosage of 10⁷-10¹¹ CFUs (colony-forming units) per day demonstrated positive results.10,11 Apart from the dosage, timing is also a key factor when taking probiotics. For maximum effect, taking a probiotic with or after a meal is ideal to leverage the alkaline environment in the stomach, as it results in higher bacteria survival.9

How effective are prebiotics and probiotics?

Although research is continuously being conducted on prebiotics and probiotics, there is still much to be discovered about their safety and efficacy. When it comes to prebiotics, studies have demonstrated the following potential physiological benefits:4

● Increase in calcium absorption in the body3,4

● Regulation of blood sugar levels4

● Decrease in “gut transit time” due to improved bacterial fermentation in the colon4

The physiological benefits presented above demonstrate the potential for prebiotics to help with illnesses like osteoporosis, diabetes, and colon cancer.4 Currently, studies are being done to look at the effect of prebiotics on GI issues like irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and obesity.4

What about probiotics? Many health claims have been attributed to probiotic usage, but what is the truth behind all the claims? On the whole, probiotics have been linked with assisting in overall well-being, GI health, immune function, vitamin production, nutrient absorption, and microbiome equilibrium.3,5 Additionally, studies have found that probiotics can also help with the following health conditions:

● Decreasing Antibiotic-Associated Diarrhea (i.e., Diarrhea caused by the bacteria Clostridium difficile)1,5

● Alleviating some of the symptoms and abdominal pain associated with irritable bowel syndrome (IBS)1

● Bringing about or sustaining remission for ulcerative colitis1

● Relief from lactose intolerance2

● Lowering the risk of sepsis in premature infants1

● Treatment of colic in infants1

● Decreasing the number of bacteria causing periodontal disease1

Although it is safe for most healthy individuals to take probiotics, it is always essential to consult a healthcare professional before starting, especially if you are suffering from an illness or are immunocompromised. Furthermore, not all prebiotics and probiotics are created equal, and not all will present the same results.1 As a result, in selecting a probiotic, make sure to evaluate the following:

● Dosage12

● Benefits - Various strains will have varying benefits. Ensure the benefits of the probiotic align with the help you are looking for.12

● Label - Make sure the information on the label is clear and transparent, including the names of the microorganisms (using proper nomenclature), number of live organisms present (CFU) per dose, serving size, appropriate storage conditions, and company contact information.12

How beneficial are probiotics?

After taking a probiotic supplement, you may be wondering how beneficial it is as it travels through the body. Can it survive the harsh environment of the gastrointestinal (GI) tract long enough to be absorbed and utilized? The answer is yes, for the most part!

Many aspects affect the survivability of probiotics through the upper GI tract, including the amount of stomach acid present, duration of exposure to acid, and concentration and time of exposure to bile salts (produced by the liver).13 In addition, research conducted by Naissinger da Silva et al. determined that the survivability of bacteria is also affected by the form of probiotic consumed.14 For example, low concentrations of viable cells have been associated with lyophilized probiotics (freeze-dried) stored at room temperature requiring reconstitution.14 However, the good news is that certain probiotic strains remain viable in numbers even after their long journey through the GI tract and colon.13

Studies have found that acid-resistant bacteria like the Bifidobacterium sp., Lactobacillus sp., and Streptococcus sp. can survive the low pH of the stomach.14 Interestingly, research specifically investigating Bacillus, a spore-forming bacteria, found B. subtilis spores (the dormant form) were able to germinate and become active vegetative cells in the small intestine.15 This is because spore-forming probiotic strains protected within endospores are highly resistant to gastric acid, stable at room temperature, and able to transport viable probiotics to the small intestine.15,16 As a result, spore-forming probiotic strains may have greater potential to effectively reach target locations and confer health benefits.15

Another element influencing the viability of probiotics are milk and milk derivatives.14 Milk and milk-derived products like fermented milk were found to increase the viability of bacteria in low pH conditions (like digestion) due to the protective quality of fat globules and milk proteins like casein.14

Consequently, next time you purchase probiotics, consider the following as they may be associated with greater viability:14

· Probiotic supplements enclosed in capsules14

· Supplements containing acid-resistant bacteria (i.e., spore-based probiotics)14

· Probiotics linked to milk or milk derivatives (i.e., probiotic fermented milk)14

It is important to note that more research is still needed to fully understand the viability and benefits of probiotics once ingested.

Final Thoughts

Every day more is discovered about the effects of prebiotics and probiotics on the human microbiome. As we learn more, it will be fascinating to understand how prebiotics and probiotics can be most effectively used to treat, restore, and maintain health in the body.

If you are interested in taking a supplement that contains pre- and/or probiotics but aren’t sure what type may be right for you, contact Dorothy at 310.828.3000.


  1. “Probiotics: What You Need to Know.” Edited by Yisong Wang and David Shurtleff, National Center for Complementary and Integrative Health, U.S. Department of Health and Human Services, Aug. 2019,

  2. Marcel B Roberfroid, Prebiotics and probiotics: are they functional foods? The American Journal of Clinical Nutrition, Volume 71, Issue 6, June 2000, Pages 1682S–1687S,

  3. Klemm, Sarah. “Prebiotics and Probiotics: Creating a Healthier You.” EatRight, Academy of Nutrition and Dietetics, 9 June 2020,

  4. “Prebiotics.” International Scientific Association for Probiotics and Prebiotics (ISAPP), 10 Apr. 2020,

  5. “Probiotics.” International Scientific Association for Probiotics and Prebiotics (ISAPP), 18 June 2019,

  6. “Species Commonly Used as Probiotics.” Probiotic Advisor,

  7. “How to Get More Probiotics.” Staying Healthy, Harvard Health Publishing Harvard Medical School, 24 Aug. 2020,

  8. Hill, C., Guarner, F., Reid, G. et al. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nat Rev Gastroenterol Hepatol 11, 506–514 (2014).

  9. “Dosage.” Probiotic Advisor,

  10. Gionchetti P, Rizzello F, Morselli C, Poggioli G, Tambasco R, Calabrese C, Brigidi P, Vitali B, Straforini G, Campieri M. High-dose probiotics for the treatment of active pouchitis. Dis Colon Rectum. 2007 Dec;50(12):2075-82; discussion 2082-4. doi: 10.1007/s10350-007-9068-4. Epub 2007 Oct 13. PMID: 17934776.

  11. Shornikova AV, Casas IA, Mykkänen H, Salo E, Vesikari T. Bacteriotherapy with Lactobacillus reuteri in rotavirus gastroenteritis. Pediatr Infect Dis J. 1997 Dec;16(12):1103-7. doi: 10.1097/00006454-199712000-00002. PMID: 9427453.

  12. “Probiotic Checklist: Making a Smart Selection.” International Scientific Association of Probiotics and Prebiotics, 2018,

  13. Anatoly Bezkorovainy, Probiotics: determinants of survival and growth in the gut, The American Journal of Clinical Nutrition, Volume 73, Issue 2, February 2001, Pages 399s–405s,

  14. Maritiele Naissinger da Silva, Bruna Lago Tagliapietra, Vinícius do Amaral Flores, Neila Silvia Pereira dos Santos Richards, In vitro test to evaluate survival in the gastrointestinal tract of commercial probiotics, Current Research in Food Science, Volume 4, 2021, Pages 320-325, ISSN 2665-9271, (

  15. Hancocks, N., 2021. First-of-its-kind study reveals germination of spore-forming probiotics in GI tract. [online] Available at: <> [Accessed 20 February 2022].

  16. McFarlin BK, Henning AL, Bowman EM, Gary MA, Carbajal KM. Oral spore-based probiotic supplementation was associated with reduced incidence of post-prandial dietary endotoxin, triglycerides, and disease risk biomarkers. World J Gastrointest Pathophysiol. 2017;8(3):117-126. doi:10.4291/wjgp.v8.i3.117

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