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Chr. Hansen’s Lactobacillus paracasei, L. CASEI 431®

A well-documented probiotic strain supporting immune function

Lactobacillus paracasei, L. CASEI 431® (hereafter referred to by use of the trademark L. CASEI 431®) was initially isolated from the fecal sample of a healthy infant and has been described in more than 90 scientific publications, of which more than 20 are publications from human scientific studies.  

The L. CASEI 431® probiotic strain is well-documented and has been associated with health benefits within several areas of health, including immune health, respiratory healthy and bowel function. 

The L. CASEI 431® strain is highly stable and able to survive in the gastrointestinal tract. It has been used in food and dietary supplements since 1995. 


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Strain characteristics and specifications

Studied extensivelyLactobacillus paracasei, L. CASEI 431® has high acid and bile tolerance.1 Recent lab-based research has shown that the L. CASEI 431® strain is an excellent survivor of both gastric acid solution at pH 2.5 and 1% porcine bile solution. These characteristics enable the probiotic strain to survive the journey through the gastrointestinal tract. Only once it has passed through the gastrointestinal tract is it able to influence health beneficially. (Ref: Data from Chr. Hansen Human Health Development).

The L. CASEI 431® probiotic strain has good intestinal mucosal adherence, which may reduce adherence by potentially harmful bacteria,1 as well as barrier function support2 and immune interactions.3


In high-quality scientific studies, the L. CASEI 431® strain has shown that it may: 

  • Support the immune response4-7 
  • Help support healthy immune molecule responses2  
  • Help increase the number specific antibodies produced in response to a challenge4, 6-7 
  • Help reduce duration of respiratory discomfort5 
  • In combination with Bifidobacterium, BB-12®, the L. CASEI 431® strain may help support normal stool frequency and consistency in infants.

Granted QPS status in Europe 

The L. CASEI 431® strain is safe for human consumption and has been granted QPS (Qualified Presumption of Safety) status by EFSA in Europe. 

It has been tested in randomized double blinded placebo controlled studies at levels of up to at least 50 billion CFU/day (colony forming units), alone and in combination with Bifidobacterium, BB-12® with no safety issues. 


Summary of important information about the L.CASEI 431® strain

  • Scientific studies show that the L.CASEI 431® probiotic strain may support immune function 
  • One of the best documented probiotic strains in the world 
  • Good results within immune and respiratory health areas.


L. CASEI 431® from Chr. Hansen is unique due to

  • Superior stability 
  • Good survival within the gastrointestinal tract 
  • High level scientific data.  


L. CASEI 431® and BB-12® are registered trademarks of Chr. Hansen A/S.




1 Jacobsen CN, et al. Appl Environ Microbiol. 1999;65(11):4949-56.
2 Internal Chr. Hansen data on file.
3 Zeuthen LH, et al. Clin Vaccine Immunol. 2006;13(3):365-75.
4 Rizzardini G, et al. Br J Nutr. 2012;107(6):876-84.
5 Jespersen L, et al. Am J Clin Nutr. 2015;101(6):1188-96.
6 Trachootham, D. et al.  Journal of Functional Foods. 2017;33, 1–10. 
7 De Vrese, M. et al.  European Journal of Nutrition. 2005;44(7), 406–413.
8 Vlieger AM, et al. Br J Nutr. 2009;102(6):869-75.
9 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.


This communication is only intended for business-to-business and health care professionals. This communication is not intended for consumers of final consumer goods. Nothing on this page is meant to be perceived as an approved claim.

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