Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Feb 11;16(2):e0246953.
doi: 10.1371/journal.pone.0246953. eCollection 2021.

Lactic acid-containing products for bacterial vaginosis and their impact on the vaginal microbiota: A systematic review

Erica L Plummer  1   2 , Catriona S Bradshaw  1   2 , Michelle Doyle  2 , Christopher K Fairley  1   2 , Gerald L Murray  3   4   5 , Deborah Bateson  6   7 , Lindi Masson  1   8   9   10   11 , Josephine Slifirski  2 , Gilda Tachedjian  8   12   13 , Lenka A Vodstrcil  1   2
Affiliations

Lactic acid-containing products for bacterial vaginosis and their impact on the vaginal microbiota: A systematic review

Erica L Plummer et al. PLoS One. .

Abstract

Objective: The vaginal microbiota in bacterial vaginosis (BV) typically has low abundance of lactic acid producing lactobacilli. Lactic acid has properties that may make it effective for treating BV and/or restoring an optimal lactobacillus-dominated vaginal microbiota. We conducted a systematic review to describe the effect of intravaginal lactic acid-containing products on BV cure, and their impact on vaginal microbiota composition (PROSPERO registration: CRD42018115982).

Methods: PubMed, Embase and OVID were searched from inception to November 2019 to identify eligible studies. Included studies evaluated an intravaginal lactic acid-containing product and reported BV cure using established diagnostic methods, and/or vaginal microbiota composition using molecular methods. Studies were independently screened and assessed, and the proportion of women cured post-treatment was calculated. Study results were described in a qualitative manner.

Results: We identified 1,883 articles and assessed 57 full-texts for eligibility. Seven different lactic acid-containing products were evaluated and differed with respect to excipients, lactic acid concentration and pH. Most studies had medium or high risk of bias. Three trials compared the efficacy of a lactic acid-containing product to metronidazole for BV cure. One study found lactic acid to be equivalent to metronidazole and two studies found lactic acid to be significantly inferior to metronidazole. Two studies included a control group receiving a placebo or no treatment. One reported lactic acid to be superior than no treatment and the other reported lactic acid to be equivalent to placebo. Lactic acid-containing products did not significantly impact the vaginal microbiota composition.

Conclusion: There is a lack of high-quality evidence to support the use of lactic acid-containing products for BV cure or vaginal microbiota modulation. However, adequately powered and rigorous randomised trials with accompanying vaginal microbiota data are needed to evaluate the efficacy of lactic acid as a BV treatment strategy.

PubMed Disclaimer

Conflict of interest statement

I have read the journal’s policy and the authors of this manuscript have the following competing interests: GT is a coinventor on patent application AU201501042 and United States Patent No. US 9,801,839 B2 claiming the anti-inflammatory effects of lactic acid. No other authors report a conflict of interest.

Figures

Fig 1
Fig 1. PRISMA flow diagram describing the literature search and article selection process.
a Detailed reasons for exclusion are provided in S3 Table.
Fig 2
Fig 2. Risk of bias assessment.
+ indicates a low risk of bias, -/+ indicates moderate risk of bias,—indicates high risk of bias,? indicates unknown risk, NA indicates bias is not applicable to the study. a Other sources of bias include whether confounders were appropriately accounted for and whether lactic acid-containing product details were sufficiently described in the manuscript. b One study disclosed receipt of funding from the lactic acid-containing product manufacturer. c Single arm prospective cohort study.
See this image and copyright information in PMC

References

    1. Brotman RM, Klebanoff MA, Nansel TR, Yu KF, Andrews WW, Zhang J, et al. Bacterial vaginosis assessed by Gram stain and diminished colonization resistance to incident gonococcal, chlamydial, and trichomonal genital infection. J Infect Dis. 2010;202(12):1907–15. 10.1086/657320 - DOI - PMC - PubMed
    1. Koumans EH, Markowitz LE, Berman SM, St Louis ME. A public health approach to adverse outcomes of pregnancy associated with bacterial vaginosis. Int J Gynaecol Obstet. 1999;67 Suppl 1:S29–33. 10.1016/s0020-7292(99)00136-8 - DOI - PubMed
    1. Myer L, Kuhn L, Stein ZA, Wright TC Jr., Denny L. Intravaginal practices, bacterial vaginosis, and women’s susceptibility to HIV infection: epidemiological evidence and biological mechanisms. Lancet Infect Dis. 2005;5(12):786–94. 10.1016/S1473-3099(05)70298-X - DOI - PubMed
    1. Low N, Chersich MF, Schmidlin K, Egger M, Francis SC, van de Wijgert JH, et al. Intravaginal practices, bacterial vaginosis, and HIV infection in women: individual participant data meta-analysis. PLoS Med. 2011;8(2):e1000416 10.1371/journal.pmed.1000416 - DOI - PMC - PubMed
    1. Cohen CR, Lingappa JR, Baeten JM, Ngayo MO, Spiegel CA, Hong T, et al. Bacterial vaginosis associated with increased risk of female-to-male HIV-1 transmission: a prospective cohort analysis among African couples. PLoS Med. 2012;9(6):e1001251 10.1371/journal.pmed.1001251 - DOI - PMC - PubMed

Publication types