Freya - Woman's Health Research
Research type
Research Study
Full title
Vaginal Colonization of Lactobacillus acidophilus and Lacticaseibacillus rhamnosus in Healthy Females: A Double-Blind, Randomized, Placebo-Controlled Trial
IRAS ID
287782
Contact name
Reeta Ala-Jaakkola
Contact email
ISRCTN Number
ISRCTN29375062
Duration of Study in the UK
0 years, 5 months, 1 days
Research summary
Research Summary
This study has been designed to investigate the effect of a probiotic supplement on the natural bacteria of the vagina in healthy females. A healthy environment (microflora) in the vagina is supported by the presence of large numbers of certain bacteria called lactobacilli (lack-toe-buh-sill-eye). Lower number of these bacteria have been associated with a risk of health problems such as Bacterial Vaginosis (BV), yeast infections, and urinary tract infections (UTIs).
It is believed that by taking a regular probiotic supplement containing lactobacilli by mouth, this can help increase the numbers of lactobacillus bacteria in the vagina. The reason for this is not entirely clear, but initial studies in both mice and healthy women have successfully shown this effect on the vaginal microflora. While similar studies have already been done, this study is different because it will look at the effects of only two specific lactobacillus bacteria in the probiotic supplement.The healthy vaginal microbiota is characterized by its high abundance with members of the genus Lactobacillus. The most commonly detected lactobacilli in the healthy vagina are Lactobacillus crispatus, Lactobacillus jensenii, and Lactobacillus gasseri (Smith and Ravel 2017). A reduced proportion of lactobacilli in the vaginal microbiota is associated with disease or increased disease risk, such as Bacterial Vaginosis (BV), candida infections, and urinary tract infections (UTI) (Onderdonk et al. 2016, van de Wijgert et al. 2017). These infections are the most common urogenital infections in women of reproductive age. Despite available therapies (antibiotics and antifungal medication), not all women respond to the treatment and recurrence rates over time among responders remain significant. As probiotics are commonly lactobacilli, their use provides an attractive approach to increase the levels of vaginal lactobacilli (Borges et al. 2014). In addition, in the vaginal tract probiotics are considered to provide antimicrobial activity by reducing vaginal pH via lactic acid production, producing hydrogen peroxide, and potentially bacteriocins, and modulating immune responses. Furthermore, vaginal probiotics are expected to adhere to vaginal epithelial cells and thereby exclude potential pathogens.
Summary of Results
The aim of the current study was to assess if La-14 and HN001 supplemented without lactoferrin could colonize the vagina. Lactoferrin is a glycoprotein naturally present also in vaginal secretions and is mainly involved in the innate immune defence against pathogens. The 50-100 mg of lactoferrin included in the investigational product in addition to La-14 and
HN001 supplemented was considered an unlikely reason for colonization of supplemented species as lactoferrin is digested to a large extent in the upper GI tract, especially in the stomach.The healthy vaginal microbiota is characterized by its high abundance with Lactobacillus. Both of the supplemented species, L. acidophilus and L. rhamnsous, can also be detected in the vaginal microbiota, even without being supplemented as an intervention or when placebo has been supplemented.
Neither of the two primary hypotheses could not be formally analysed due to the fact, that colonization of either supplemented strain was not detected on species level with the applied molecular methods. Therefore, the null hypotheses could not be rejected. The vaginal pH remained stable throughout the intervention. No safety concerns in relation to the use of the IP were observed.
REC name
East of Scotland Research Ethics Service REC 1
REC reference
20/ES/0089
Date of REC Opinion
9 Oct 2020
REC opinion
Further Information Favourable Opinion