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Safety in the world of probiotics 

- development of safe probiotics is key at Chr. Hansen

Scientists and researchers working with safety within probiotcs
6 Min read

Numerous health benefits have been associated with probiotics, which have safely been used in a variety of clinical studies.

Probiotic safety

Different types of lactobacillus strains have been ingested in fermented milk by humans for thousands of years in the belief that they have health benefits. The potential benefits have been increasingly subjected to investigation, via in vitro and in vivo studies, and human randomized, double-blinded trials. High quality studies link specific probiotic strains with particular health benefits.1 With this widespread clinical and commercial use of probiotics, their safety must be rigorously assessed to ensure they are safe for human consumption. At Chr. Hansen, we ensure high quality, strain safety and purity for all our products. As an example, see the illustration below.

Safety  in probiotics related to production environment and raw materials

Several probiotic strains are considered safe to consume in generally healthy individuals. Many probiotic strains have been evaluated by the European Food Safety Authority (EFSA) and subsequently have been granted QPS (Qualified Presumption of Safety) status in the EU. In addition, there are several probiotic strains that have been safety assessed, with submissions to the US Food and Drug Administration (FDA) of GRAS (Generally Recognized as Safe) notices. At Chr. Hansen extra quality and safety are employed when producing products that may be used as supplements for different populations, including premature infants, hospitalized patients, etc.

Quality criteria must be met at each production step
If not, manufacturing
is re-started
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Probiotic use and sepsis

Reviews of probiotic use summarize an overall excellent safety record, with minimal adverse events for humans.4, 5 There are a number of published cases of probiotic bacteremia (a bacterial infection in the blood stream) in preterm infants and in patients with a compromised immune system, central venous catheter, chronic disease, or some debilitation.1 However, in otherwise healthy people, there have been no reports of probiotic bacteremia.1

The table below gives an overview of risk factors which merit caution when choosing and recommending a probiotic product making sure it lives up to rigorous safety and quality measures.

Proposed risk factors for probiotic sepsis*
Major risk factors
Immunocompromised patients
Premature infants
Minor risk factors
Central venous catheter
Impaired intestinal epithelial barrier, e.g. intestinal inflammation
Concomitant administration of broad-spectrum antibiotics to which probiotic is resistant
Cardiac valvular disease (Lactobacillus probiotics only)

*Modified from Boyle et al, 20061

In summary, probiotics are safe to use in otherwise healthy individuals. Based on the characteristics of the cases reported, caution is warranted when recommending probiotics to immunocompromised patients, premature infants, and patients who possess a single major risk factor or more than one minor risk factors.

Chemist ensuring safety on probiotics

Qualified Presumption of Safety (QPS)2

The European Food and Safety Authority (EFSA) assesses the safety of microorganisms used in food before their use in the European market. Based on the most up to date reasonable scientific evidence, the Qualified Presumption of Safety (QPS) status is an indication that there are no significant safety concerns for human consumption for healthy individuals.

To be granted QPS status, a microorganism must meet the following criteria:

  • Its taxonomic identity must be well defined
  • The available body of knowledge must be sufficient to establish its safety
  • Established and substantiated lack of pathogenic properties
  • Its intended use clearly described

Any microorganisms not well-defined must undergo a full safety assessment before being suitable for QPS status, as safety concerns cannot be identified and, therefore, it is not possible to conclude if they pose a risk to humans.

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.


References Open Close

1. Boyle RJ, et al. Probiotic use in clinical practice: what are the risks? Am J Clin Nutr. 2006;83(6):1256-64; quiz 446-7. (PubMed)
2. EFSA Panel on Biological Hazards (BIOHAZ). Statement on the update of the list of QPS-recommended biological agents intentionally added to food or feed as notified to EFSA 3: Suitability of taxonomic units notified to EFSA until September 2015. EFSA Journal. 2015;13:4331.
3. Food and Drug Administration. GRAS Notice Inventory > Agency Response Letter GRAS Notice No GRN 000049. 2002.
4. Borriello SP, et al. Safety of probiotics that contain lactobacilli or bifidobacteria. Clin Infect Dis. 2003;36(6):775-80. (PubMed)
5. Ishibashi N, Yamazaki S. Probiotics and safety. Am J Clin Nutr. 2001;73(2 Suppl):465s-70s. (PubMed)
6. Salminen MK, et al. Lactobacillus bacteremia during a rapid increase in probiotic use of Lactobacillus rhamnosus GG in Finland. Clin Infect Dis. 2002;35(10):1155-60. (PubMed)
7. Saxelin M, et al. Lactobacilli and bacteremia in southern Finland, 1989-1992. Clin Infect Dis. 1996;22(3):564-6. (PubMed)

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What to
look for

See key tips on how to choose a high-quality probiotic product


Learn how to review the evidence when considering probiotic strains and effects


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

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