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Science, Ingredients

Probiotic Strain Focus: Women’s Health

Written by: Victoria Hanlon
Senior Writer

Our bodies are full of “good” bacteria, consisting of tiny microorganisms which are on a constant mission to crowd out “bad” bacteria and keep the body functioning healthily. Scientists have been able to identify that good bacteria comes in different types, or “strains”, which all have different beneficial effects on the body.

Ladies, meet your bacterial mates

Healthy vaginal flora is supported by a bacterial strain known as Lactobacilli. This lives in the vagina and helps to keeps the vaginal environment balanced, by colonizing the urogenital area and fighting off unwelcome bacteria and fungi[1].

However, according to one study, around only 40% of women had normal levels of Lactobacillus-dominated flora, with only a fraction of this 40% experiencing symptoms[2]. Studies have also shown that vaginal microflora is constantly in a state of flux and at many points during the menstrual cycle there can be a reduction in Lactobacillus levels[1]. This can lead to conditions such as vaginitis and impact urinary tract health[1,2,3,4].

To help maintain vaginal health, you can support the presence of two specific lactobacilli strains in your body, Lactobacillus rhamnosus (GR-1) and Lactobacillus reuteri (RC-14)[1,2].

Lactobacillus rhamnosus GR-1

This bacteria strain is very well documented as being beneficial for women’s health. It is believed to adhere to cells in the urinary tract, vagina and intestine, which restores healthy microbial balance, in part by inhibiting the growth of harmful bacteria and yeast[1,3].

Fun fact: It’s a lactic acid forming bacteria and is rod-shaped[5].

Lactobacillus reuteri RC-14

This is another firm favourite for women’s health and is commonly used in combination with Lactobacillus rhamnosus GR-1. Similar to its partner, it works in part by adhering to the surfaces of the urogenital areas in women, thereby pushing out “bad” bacteria and preventing it from growing[1,3].

Fun fact: It was originally isolated from the vagina of a healthy woman[6] and was initially known as Lactobacillus acidophilus RC-14, before being reclassified as Lactobacillus reuteri RC-143.

To help support levels of Lactobacilli in your body, you can consider taking a probiotic designed to support women’s health[1,2,4]. Swisse Ultibiotic Women’s Flora Probiotic contains both Lactobacillus rhamnosus (GR-1) and Lactobacillus reuteri (RC-14), and is specifically formulated to support healthy vaginal flora and maintain urinary tract health.

Always read the label. Follow the directions for use. If symptoms persist, talk to your health professional.



  1. Reid G, Charbonneau D, Erb J, et al. Oral use of Lactobacillus rhamnosus GR-1 and L. fermentum RC-14 significantly alters vaginal flora: randomized, placebo-controlled trial in 64 healthy women. FEMS Immunol Med Microbiol. 2003;35(2):131-134. doi:10.1016/S0928-8244(02)00465-0
  2. Reid G, Beuerman D, Heinemann C, Bruce AW. Probiotic Lactobacillus dose required to restore and maintain a normal vaginal flora. FEMS Immunol Med Microbiol. 2001;32(1):37-41. doi:10.1111/j.1574-695X.2001.tb00531.x
  3. Anukam K, Osazuwa E, Ahonkhai I, et al. Augmentation of antimicrobial metronidazole therapy of bacterial vaginosis with oral probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14: randomized, double-blind, placebo controlled trial. Microbes Infect. 2006;8(6):1450-1454. doi:10.1016/j.micinf.2006.01.003
  4. Petricevic L, Unger FM, Viernstein H, Kiss H. Randomized, double-blind, placebo-controlled study of oral lactobacilli to improve the vaginal flora of postmenopausal women. Eur J Obstet Gynecol Reprod Biol. 2008;141(1):54-57. doi:10.1016/j.ejogrb.2008.06.003
  5. Cribby S, Taylor M, Reid G. Vaginal microbiota and the use of probiotics. Interdiscip Perspect Infect Dis. 2008;2008:256490. doi:10.1155/2008/256490
  6. Hsieh MH, Versalovic J. The human microbiome and probiotics: implications for pediatrics. Curr Probl Pediatr Adolesc Health Care. 2008;38(10):309-327. doi:10.1016/j.cppeds.2008.09.001


Victoria Hanlon - Senior Writer

Science, Ingredients