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Myths & misconceptions about probiotics 

- what’s true and what’s not? 

Person checking myth and misconceptions of probiotics
6 Min read

The probiotics market is growing, but so with it are the number of misunderstandings about probiotic products and their effects. In this article we address some of the more common probiotic misconceptions.  

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What to do when choosing a probiotic:

  • Check the specific strain and the related level that is needed for your desired health benefit

  • Choose a probiotic product that has proven health benefits

  • Remember that different probiotic strains have different health benefits, and these are not generalizable across all probiotic products

1) Are all probiotics the same?


Probiotic bacterial strains have very different properties. This means that there is a large variety of probiotic products available that have various effects. The health benefit is specific to the particular bacterial strain, and not the more general bacterial species. For example, a product may be labelled Lactobacillus rhamnosus, but whether the strain is Lactobacillus rhamnosus, LGG® , the very different Lactobacillus rhamnosus, GR-1®, or any other Lactobacillus rhamnosus strain, is not known, nor is there necessarily the same level of scientific support for the potential health benefit.

Click to read more on ‘what are probiotics’ 

2) Are probiotics with more bacteria the most effective?

Not necessarily 
A probiotic product with more bacteria does not necessarily have a superior effect. Some probiotic strains require a relatively low number of bacteria, while other strains require much more to provide the desired effect. 

It is therefore much more important to choose a probiotic that has been scientifically associated with a particular health benefit at the level studied. This means that the appropriate level actually depends on the strain, and the studied effect within a specific health area.
Click to read more about probiotics associated with colds and flu-like symptoms or probiotics and diarrhea or probiotics and excessive crying and fussing

3) Do probiotic products with more than one strain work better?

Not necessarily 

Some probiotic products contain more than one probiotic strain, but this does not automatically mean that the product is more effective. Many multi-strain products lack the clinical support for the particular combination of strains they contain. 

Instead, the best probiotic product to choose is the one that contains a particular strain (or particular combination of strains) that has been studied and associated with particular health benefits.
Click to read more about the Chr. Hansen UREX probiotic blend, or the LGG®, BB-12®, LA-5®or L. CASEI 431® single strain probiotics.

Healthy family and probiotics

4) Do all fermented foods contain probiotic bacteria?


Fermented foods, such as kombucha, sauerkraut or tempeh, are developed by using the bacteria that are naturally present in the food or by adding live bacteria to a food product. Often, a fermented food will go through further processing such as pasteurization, baking or filtering. This processing kills the live bacteria, preventing the product from qualifying as a probiotic because it no longer contains live bacteria. 

To be classified as a probiotic, products must contain live bacteria, they must have established health benefits supported by human studies, and they must contain the appropriate level of bacteria.1
If a fermented food does not meet the above criteria, there is no way of knowing the level consumed or whether its anticipated health benefits have been scientifically supported. Have those strains been studied at the level associated with a specific health effect? These are all important points to consider when looking for a probiotic product to support your health.

Despite many fermented foods and beverages not being probiotic, they may still be nutritious and contribute to a balanced diet.
Click to read more on ‘what are probiotics’

5) Do all yogurts contain probiotics?

Not all yogurts do

Yogurts can be a good source of probiotics but not all yogurts contain probiotics. All yogurts are made by adding live bacteria to milk, but not all live bacteria provide specific health benefits. Some yogurt products contain specific probiotic bacterial strains that have been added together with the fermenting culture. Deliberate addition of clinically tested probiotic strains at the documented level ensure that the yogurt contains live bacteria that have scientific support for helping maintain good health. It also ensures that enough of the probiotic bacteria is added for the bacteria to still be alive on the expiry date. This is key, as the bacteria must be alive for the yogurt to be considered a probiotic yogurt and to have a probiotic effect when consumed.
Probiotic bacteria such as Bifidobacterium, BB-12®, Lactobacillus acidophilus, LA-5®, Lactobacillus rhamnosus, LGG® or Lactobacillus paracasei, L. CASEI 431® can be added during the production of yogurt, making it a source of probiotic bacteria.
Click to read more on ‘what are probiotics’.

6) Can probiotic products be used while taking antibiotics?


Antibiotics can have negative side effects on our health because they disrupt the balance of bacteria in our body. Probiotics can help balance these levels of bacteria, which may help lessen the side effects. For example, antibiotics can cause diarrhea, but research has associated consumption of the Lactobacillus rhamnosus, LGG® probiotic strain with fewer cases of diarrhea when taking antibiotics.2, 3 When combining antibiotics with probiotic supplementation, it is suggested that the probiotics are taken a few hours after the antibiotics.

7) Have probiotic strains been associated with positive health benefits?


Yes, studies suggest that some probiotic strains can provide health benefits
The health benefits of some probiotic strains have been studied in human clinical trials. It should be remembered that the proven benefits of one probiotic strain on a particular area of health cannot be generalized to other probiotic strains or other areas of health. It is important to consider these points when choosing a probiotic product.
Click to read more about what to look for when choosing a probiotic product 
You can also read about the Chr. Hansen probiotic strains here.


8) Is it common to isolate probiotic strains from various sources?

Remember that probiotic strains are bacteria, entirely separate entities in the classification of all living organisms4. It is also important to first establish that probiotic strains are microorganisms that can live in a variety of areas, and the source of the isolation does not determine what comprises the microorganism, nor do they bring with them any component of where they are found and/or isolated from.

Humans are born without a microbial population, and the resident microbes of any individual develop throughout different stages of life. For example, the microbiome can be seeded from a mother to an infant during vaginal delivery, and further impacted through breastfeeding and later exposure to foods, people and the environment. The microorganisms found in humans co-exist with us and take up residence in a niche that supports their growth until they move along and inhabit another host, or environment, or food.

Thus, the isolation source of probiotic strains is varied in nature, reflecting the diversity of environments from which humans are exposed to beneficial bacterial. With that in mind, commonly seen isolation sources for probiotics include human intestinal (more commonly in the form of a feces sample) and vaginal samples, environmental samples and various food sources, such as fermented dairy products and other naturally fermented food sources.


9) Are probiotic strains isolated from humans more ideal for human consumption?


Reputable international scientific organizations have never considered that the "origin" of a strain is a prerequisite for probiotic benefits. The World Health Organization (WHO) defines probiotics as "live microorganisms that, when administered in adequate amounts, confer a health benefit on the host"5. Nowhere in the probiotic definition is origin mentioned. In addition, the International Scientific Association for Probiotics and Prebiotics (ISAPP) states that "a high-quality, effective probiotic does NOT have to be" naturally found in the human gut or "human-derived"8 .

What is important to remember is that human health benefits have been established for probiotic strains isolated from plants, foods, human feces, animals, and other sources. With regards to choosing probiotics with supporting health benefits, it is more important to rely on the safety of the proven science and clinical documentation on the strains rather than to focus on their origin of isolation. In other words, proving that a microbial culture is safe and efficacious through science is what makes a probiotic, not where it was isolated from.

Click to read more about Chr. Hansen’s probiotic strains, some of the world’s most documented.


10) Many consumers today prefer to buy more natural products. Can probiotic strains isolated from humans be considered more "natural" than ones isolated from other sources?


Probiotic strains are bacteria that can be found in every habitat on Earth7. As such, there is no agreed-upon definition what constitutes a "natural" probiotic in the way that it is understood from most consumers’ perspectives.

As mentioned above, humans are born without a resident microbial community, and rather acquire microbes throughout different life-stages through contact with other people and the environment, and foods that are eaten. In fact, the human body is constantly exposed to bacteria from a variety of sources, and this diversity is an important component of a healthy intestinal microbiome, especially when you consider the evidence of disease incidence being reduced in populations that have pets, siblings or live with animals (i.e., more rural settings)8,9.

Again, independent of the isolation source, what is critical is that the microbial culture being consumed as a probiotic has been shown to provide a health benefit on the host, while also possessing required safety parameters. In fact, there is a multitude of probiotic strains not isolated from humans that have been demonstrated to show benefits on human health.


BB-12®, LA-5®, L. CASEI 431®, LGG® GR-1® and UREX are trademarks of Chr. Hansen A/S.

The article is provided for informational purposes regarding probiotics and is not meant to suggest that any substance referenced in the article is intended to diagnose, cure, mitigate, treat, or prevent any disease.

Our Chr. Hansen probiotic strains

At Chr. Hansen, our strains are backed by science. All of our probiotic strains are supported by clinical documentation. Learn more about the beneficial effects our strains have on different health areas.


References Open Close

1. Hill C, 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. 2014;11:506. (PubMed)

2. Arvola T, et al. Prophylactic Lactobacillus GG reduces antibiotic-associated diarrhea in children with respiratory infections: a randomized study. Pediatrics. 1999;104(5):e64. (PubMed)

3. Vanderhoof JA, et al. Lactobacillus GG in the prevention of antibiotic-associated diarrhea in children. The Journal of Pediatrics. 1999;135(5):564-8. (PubMed)

4.Taxonomy - Five-Kingdom Classification, Prokaryotic Monera, and Multitissued Organisms | Britannica

5. Hill, C. et al.Nat. Rev. Gastroenterol. Hepatol 11, 506–514 (2014).


7. Bacteria | What is microbiology? | Microbiology Society

8. Tun, H.M., Konya, T., Takaro, T.K. et al. Exposure to household furry pets influences the gut microbiota of infants at 3–4 months following various birth scenarios. Microbiome 5, 40 (2017).

9. Laursen MF, Zachariassen G, Bahl MI, Bergström A, Høst A, Michaelsen KF, Licht TR. Having older siblings is associated with gut microbiota development during early childhood. BMC Microbiol. 2015 Aug 1;15:154. doi: 10.1186/s12866-015-0477-6. PMID: 26231752; PMCID: PMC4522135.

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Read more about some of the world’s most documented probiotic strains and their diverse, beneficial health effects

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