Lactobacillus reuteri strains

The first strain of Lactobacillus reuteri (L. reuteri) for human use, L. reuteri DSM 17938, was isolated in 1990 from the breast milk of a Peruvian mother living in the Andes. The commercial name is L. reuteri Protectis. Other human strains from BioGaia are L. reuteri ATCC PTA 5289 and ATCC PTA 6475. L. reuteri ATCC PTA 5289 used in oral health products was isolated from the oral cavity of a Japanese woman with remarkably good dental status and L. reuteri ATCC PTA 6475 was isolated from breast milk in Finland.

To date the efficacy and safety of BioGaia’s different strains of L. reuteri have been documented in 184 clinical studies in 15,500 people of all ages. Results have been published in 159 papers in scientific journals (February 2018). This makes it one of the most studied probiotics in the world. BioGaia’s commercial strains of L. reuteri are all of human origin and isolated from breast milk and saliva.


BioGaia's history

BioGaia´s history goes back to the 1980´s, at the time when HIV was discovered. The two scientists Sven Lindgren and Walt Dobrogosz were investigating different probiotics in order to see what effects they had in this area. Read more


Dosage and colonization 

Based on clinical data 100 million CFU per day has been chosen as a safe and efficient dose of L. reuteri Protectis for humans. Further, since L. reuteri colonization is transient, dosing should be maintained to ensure adequate and stable L. reuteri levels in the gastrointestinal tract. Colonization of L. reuteri Protectis has been shown throughout the entire human gastrointestinal tract using biopsies technique.


Probiotic strains and safety

BioGaia’s probiotic products with L. reuteri are among the most scientifically well-documented probiotics in the world with regard to both efficacy and safety, tested in 15,500 infants, children and adults.

Safety has been proven in preterm babies, infants, children, healthy adults and immune compromised adults. No serious adverse effects have been observed up to the maximum tested dosage of 10 billion CFU per day, meaning 1000 times the recommended daily dose.

Lactobacillus reuteri is considered safe as it fulfills the following criteria


  • human origin
  • named and classified according to correct taxonomy
  • manufactured under controlled conditions to eliminate contamination
  • safety is avaluated and documented on target population
  • harbors no toxins or transferrable antibiotic resistance genes

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Our research

To date, 184 clinical studies using BioGaia’s human strains of L. reuteri have been performed on 15,500 individuals of all ages (February 2018).

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About BioGaia

BioGaia is an innovative Swedish health care company and a world leader in probiotics.

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Probiotics grounded in evolution Driven by science

Lactobacillus reuteri is one of few bacteria that has co-evolved with humans since the beginning of time, and because of that they are adapted to their host.

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