Saccharomyces cerevisiae CNCM I-3856 of Gnosis by Lesaffre – branded Quatreflora – may exert benefits in preventing or restoring the imbalance of the vaginal microbiota after oral administration, says a new randomised pilot clinical study. Results were officially presented during the “Probiota Americas 2019” in the special section of scientific posters. (Decherf A, Dehay E, Boyer M, Duthoy S, Rodriguez B, Legrain-Raspaud S. Migration of the probiotic Saccharomyces cerevisiae CNCM I-3856 from intestine to vagina after oral administration: a randomised pilot clinical study. Probiota Americas, 24-26 June 2019, Vancouver, Canada).

The study followed 60 healthy women of childbearing age, with regular menstrual cycles, normal vaginal flora and normal vaginal pH, with the same efficient contraception method since at least three months.


The migration of the probiotic from intestine to vagina has been proven after a daily four week oral supplementation: 21% of women who have taken 500mg of yeast probiotic presented migration of the Lesaffre’s probiotic strain in the vagina microbiota.

This proportion is comparable to what have been observed with lactobacilli probiotics, especially in one study where the probiotic was revealed in the vaginal microbiota of five out of 20 women (25%) after a four week supplementation.

Quatreflora showed a pronounced ability to survive all along the gastrointestinal tract.

“As far as we know, the migration of a probiotic yeast from rectum to vagina has never been described before our pilot clinical study,” said Silvia Pisoni, marketing manager of the company.

“Probiotics are very promising candidates in preventing or restoring the imbalance of the vaginal microbiota. According to the findings of the trial we really believe Quatreflora may contribute to the delicate women health."

References: unpublished data / patent pending WO20140096566. This clinical trial has been registered:, NCT03574844, approved by the French Ethics Committee Nord-Ouest III and authorized by the French Health Authority ANSM. It has been exclusively funded by the Lesaffre Group.