Women and Probiotics: More Important Than You Think?

Danielle Huntsman, MS, CNS, LDN

Probiotics for women and men are commonly used and shown to be efficacious in supporting a healthy digestive tract.* Lactobacillus is commonly used to support gastrointestinal health, yet also shown to promote and maintain normal vaginal flora.*1 Specifically, Lactobacilli produce lactic acids and hydrogen peroxide, supporting the normal balance of bacteria and an acidic pH, necessary for healthy vaginal flora.* The most well-known source of Lactobacilli species is found in yogurt, kefir, and sauerkraut.

Urogenital Health*

Over 50 microbial species are found in the vaginal tract; hormonal changes, hygiene habits, pH, age, and sexual activity can influence the type and number of species.2 The health of the vaginal microbiota influences urogenital health; it is estimated 1 billion women struggle with urogenital health yearly.

Specific species within the vaginal mucosa differ during premenopause, perimenopause and postmenopause. Across all stages, Lactobacillus is the most abundant genus and shown to be the most dominant bacteria within the vaginal microbiota, 83% in premenopausal women, 83% in perimenopausal women and 54% in postmenopausal women.3

A double blind, placebo-controlled, randomized clinical trial evaluated the use of two specific Lactobacillus strains (Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14) in 125 premenopausal women with occasional vaginal discomfort.*4 All participants received conventional agent for the first seven days, and randomized to receive 1 billion of both Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 or placebo twice daily from day 1 to day 30. On day 30, within the placebo group (receiving conventional agent only), 40% of the women in the placebo group had normalized vaginal microbial balance. In the group who received the combination of probiotics, vaginal microbial balance was normalized in 88% of the women, more than double than the placebo group.*

A second double blind, randomized, placebo-controlled study assessed the use of Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 compared to placebo in women experiencing occasional vaginal discomfort.* A total of 544 participants received either the probiotic or placebo capsule daily for six weeks. Results concluded 61.5% of the women receiving the probiotics felt significant improvement when compared to baseline.*5 Methods of assessment were gynecological examinations and and vaginal swabs. After an additional six weeks (without the use of probiotics), healthy vaginal microbial balance was still maintained in 51.1% of women in the probiotic group.

Probiotics and Pregnancy

Healthy prenatal and postnatal nutrition supports microbiological and immunological development; with the development of the microbiome starting in utero and influenced during delivery and after birth.6,7

Human breast milk is rich in bacteria such as Lactobacilli, Bifidobacteria, Streptococci, and Staphylococci which all play a role in the colonization and development of a newborn's immune system and intestinal microbiome.8 The consumption of probiotic containing milk was shown to be well tolerated in Norwegian mothers.9 The study was completed from 2002 to 2008, using milk-based products with higher amounts of live cultures of Lactobacillus. A food frequency questionnaire asked the women about the frequency of specific probiotic milk and probiotic yogurt products. Results concluded women consuming a higher intake of milk and yogurt probiotics (a minimum of 140mL daily) are less likely to have pregnancy complications.*

The use of probiotics, Bifidobacterium and Lactobacillus, taken as a prenatal supplement have been shown to have no effect on the probability of cesarean section, gestational period or birth weight.10,11 A randomized controlled trial evaluated the use of prenatal probiotic supplementation and dietary counseling and healthy glucose levels.10 A combination of Bifidobacterium and Lactobacillus rhamnosus or placebo was given to 256 women, starting at the first trimester. Healthy blood glucose levels were seen in women receiving probiotics and dietary counseling when compared to the placebo group; the results remained consistent 12-months postpartum.*

A meta-analysis of 11 randomized controlled trials reported the tolerance of probiotic usage during pregnancy; the total collection of the trials examined 1505 pregnant women.11 When compared to placebo, there was no significant increase or incidence of Caesarean delivery, birth weight, and gestational age in those receiving probiotics. Women started probiotic treatment (placebo, Lactobacillus alone, or in combination with Bifidobacterium) between weeks 32 and 36 of gestation; the use of the probiotic or placebo was continued until delivery.

In summary, the use of certain strains of probiotics has been shown to be supportive in women at all stages of life. During pregnancy, the use of supplementation comes to question, however, the use of Bifidobacterium and Lactobacillus have been proven to be a well-tolerated, beneficial option during pregnancy. Patients should discuss the use of a probiotic during pregnancy with their healthcare practitioner.


1. Anukam KC et al. Clin Gastroenterol 2008;42:239-43.
2. Priestley CJ et al. Genitourin Med. 997 Feb; 73(1): 23-8.
3. Brotman RM et al. Menopause (New York, NY). 2014;21(5):450-8.
4. Anukam K et al. Microbes Infect. 2006 May;8(6):1450-4.
5. Vujic G et al. Eur J Obstet Gynecol Reprod Biol. 2013 May;168(1):75-9.
6. Naut AJ et al. Print Neonatal Nurse. 2011. Apr-Jun; 25(2): 158-64.
7. Gregory K. J Print Neonatal Nurse. 2011. Apr-Jun; 25(2): 158-64.
8. Fernandez L et al. Pharmacy Res. 2013 Mar;69(1):1-10.
9. Brantsaeter A et al. Am J Epidemiol. 2011 Oct 1; 174(7): 807-15.
10. Lout R et al. Br J Nutr. 2010 Jun;103(12):1792-9.
11. Dugoua JJ et al. J Obsolete Gynaecol Can. 2009 Jun;31(6):542-52.