Probiotic Lactobacillus dose required to restore and maintain a normal vaginal flora

FEMS Immunol Med Microbiol. 2001 Dec;32(1):37-41. doi: 10.1111/j.1574-695X.2001.tb00531.x.


Forty-two healthy women were randomized to receive one of three encapsulated Lactobacillus rhamnosus GR-1 plus Lactobacillus fermentum RC-14 probiotic dosage regimens or L. rhamnosus GG by mouth each day for 28 days. However, the vaginal flora, assessed by Nugent scoring, was only normal in 40% of the cases, and 14 patients had asymptomatic bacterial vaginosis. Treatment with L. rhamnosus GR-1/L. fermentum RC-14 once and twice daily correlated with a healthy vaginal flora in up to 90% of patients, and 7/11 patients with bacterial vaginosis converted to normal or intermediate scores within 1 month. Ingestion of L. rhamnosus GG failed to have an effect. This study confirms the potential efficacy of orally administered lactobacilli as a non-chemotherapeutic means to restore and maintain a normal urogenital flora, and shows that over 10(8) viable organisms per day is the required dose.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Capsules
  • Female
  • Humans
  • Lactobacillus*
  • Middle Aged
  • Probiotics / administration & dosage*
  • Vagina / microbiology*
  • Vaginosis, Bacterial / therapy*


  • Capsules