Origins of vaginal acidity: high d/l lactate ratio is consistent with bacteria being the primary source

Boskey, Elizabeth R.; Cone, Richard A.; Whaley, Kevin J.; Moench, Thomas R.

doi:10.1093/humrep/16.9.1809

Cited by 429 publications

(325 citation statements)

References 25 publications

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“…Recent studies support the hypothesis that vaginal bacteria are the primary source of lactic acid in the vagina (Boskey et al, 1999(Boskey et al, , 2001. Lactobacilli have been recognized as the predominant microflora of the healthy human vagina to maintain a pH of , 4 .…”

Section: Introductionmentioning

confidence: 87%

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Growth and lactic acid production by vaginal Lactobacillus acidophilus CRL 1259, and inhibition of uropathogenic Escherichia coli

Tomás

Ocaña

Wiese

et al. 2003

Journal of Medical Microbiology

107

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Lactic acid-producing lactobacilli were selected from 134 human vaginal isolates by testing their capability to inhibit the growth of different pathogenic micro-organisms. Lactobacillus acidophilus CRL 1259 (from the CERELA Culture Collection) was selected to study the effects of temperature, pH and culture medium on growth and lactic acid production. Growth parameters were estimated by using the model of Gompertz. Kinetics of inhibition of uropathogenic Escherichia coli were evaluated in mixed cultures of the pathogen and L. acidophilus. Optimal conditions for growth and lactic acid production by L. acidophilus were pH 6 . 5 or 8 . 0 and 37 8C. Under these conditions, growth was higher in LAPTg (yeast extract/peptone/tryptone/Tween 80/glucose) broth than in MRS (De ManRogosa-Sharpe) broth. However, lactic acid production was more efficient in MRS broth. Under optimal conditions for lactic acid production, L. acidophilus inhibited the growth of E. coli. These results suggest that inclusion of L. acidophilus CRL 1259 in probiotic products for vaginal application would be beneficial.

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Section: Introductionmentioning

confidence: 87%

“…However, there are only a few reports concerning the growth and lactic acid production by vaginal lactobacilli (Boskey et al, 1999(Boskey et al, , 2001. In this paper, the capability of autochthonous strains of vaginal lactobacilli to inhibit growth of different pathogenic micro-organisms was analysed.…”

Section: Introductionmentioning

confidence: 97%

Growth and lactic acid production by vaginal Lactobacillus acidophilus CRL 1259, and inhibition of uropathogenic Escherichia coli

Tomás

Ocaña

Wiese

et al. 2003

Journal of Medical Microbiology

107

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“…Common wisdom attributes this to lactic acid-producing bacteria, mainly Lactobacillus sp., that commonly inhabit the vagina. These species are thought to play key protective roles by lowering the environmental pH through lactic acid production (12,13), by producing various bacteriostatic and bacteriocidal compounds, or through competitive exclusion (13)(14)(15)(16). The advent of culture-independent molecular approaches based on the cloning and sequencing of 16S rRNA genes has furthered our understanding of the vaginal microbiota by identifying taxa that had not been cultured (17)(18)(19)(20)(21)(22)(23)(24).…”

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confidence: 99%

Vaginal microbiome of reproductive-age women

Ravel

Gajer

Abdo

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

3,258

291

3,988

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The means by which vaginal microbiomes help prevent urogenital diseases in women and maintain health are poorly understood. To gain insight into this, the vaginal bacterial communities of 396 asymptomatic North American women who represented four ethnic groups (white, black, Hispanic, and Asian) were sampled and the species composition characterized by pyrosequencing of barcoded 16S rRNA genes. The communities clustered into five groups: four were dominated by Lactobacillus iners, L. crispatus, L. gasseri, or L. jensenii, whereas the fifth had lower proportions of lactic acid bacteria and higher proportions of strictly anaerobic organisms, indicating that a potential key ecological function, the production of lactic acid, seems to be conserved in all communities. The proportions of each community group varied among the four ethnic groups, and these differences were statistically significant [χ 2 (10) = 36.8, P < 0.0001]. Moreover, the vaginal pH of women in different ethnic groups also differed and was higher in Hispanic (pH 5.0 ± 0.59) and black (pH 4.7 ± 1.04) women as compared with Asian (pH 4.4 ± 0.59) and white (pH 4.2 ± 0.3) women. Phylotypes with correlated relative abundances were found in all communities, and these patterns were associated with either high or low Nugent scores, which are used as a factor for the diagnosis of bacterial vaginosis. The inherent differences within and between women in different ethnic groups strongly argues for a more refined definition of the kinds of bacterial communities normally found in healthy women and the need to appreciate differences between individuals so they can be taken into account in risk assessment and disease diagnosis. T he human body harbors microorganisms that inhabit surfaces and cavities exposed or connected to the external environment. Each body site includes ecological communities of microbial species that exist in a mutualistic relationship with the host. The kinds of organisms present are highly dependent on the prevailing environmental conditions and host factors and hence vary from site to site. Moreover, they vary between individuals and over time (1). The human vaginal microbiota seem to play a key role in preventing a number of urogenital diseases, such as bacterial vaginosis, yeast infections, sexually transmitted infections, urinary tract infections (2-9), and HIV infection (10, 11). Common wisdom attributes this to lactic acid-producing bacteria, mainly Lactobacillus sp., that commonly inhabit the vagina. These species are thought to play key protective roles by lowering the environmental pH through lactic acid production (12, 13), by producing various bacteriostatic and bacteriocidal compounds, or through competitive exclusion (13-16). The advent of culture-independent molecular approaches based on the cloning and sequencing of 16S rRNA genes has furthered our understanding of the vaginal microbiota by identifying taxa that had not been cultured (17-24). However, this technique is limited by high cost and low throughput, hence only small ...

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“…rhamnosus species [3, 4 ]. These microorganisms, which represent 80–95% of the resident bacteria, play a protective role against pathogens by different mechanisms such as the production of lactic acid, resulting in a low pH (3.5–4.5) [5,6]; the enhancement on the host’s innate immune system [7]; and the production of antimicrobial compounds, including target-specific bacteriocins [8,9] and the broad-spectrum hydrogen peroxide (H 2 O 2 ) [6,10]. The most frequent condition associated with imbalance in the vaginal microbiota is bacterial vaginosis (BV), which affects about 40–50% of women in the world [11–13].…”

Section: Introductionmentioning

confidence: 99%

Bacterial biota of women with bacterial vaginosis treated with lactoferrin: an open prospective randomized trial

Pino

Giunta

Randazzo

et al. 2017

Microbial Ecology in Health and Disease

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Background: Bacterial vaginosis is the most frequent condition associated to the vaginal microbiota imbalance, affecting about the 40–50% of women in the world. Even if antibiotics are effcetive for bacterial vaginosis treatment a long-term recurrence rates, higher than 70%, is recorded. Lactoferrin is an iron-binding glycoprotein with bacteriostatic and bactericidal properties. It owns the ability to protect the host against infection, by binding and regulating the iron needed for the bacterial proliferation.Objective: The present study was an open prospective randomized trial (registration no. SHI-EVE-2014.01) aimed at characterizing the bacterial biota of women affected by bacterial vaginosis (BV) and assessing the effects of two different lactoferrin concentrations (100 mg and 200 mg vaginal pessaries) on the composition and dynamics of the vaginal bacterial biota.Design: Sixty women with BV were recruited and randomized into two groups to receive lactoferrin pessaries for 10 days. Clinical evaluation was based on Amsel criteria and Nugent scores. Culture-dependent methods and Ion Torrent PGM sequencing of the 16S rRNA gene were applied to study in depth the overall structure of the vaginal bacterial biota and its dynamics during the treatment.Results: Vaginal lactoferrin administration modified the vaginal microbiota composition in patients with BV. During treatment, both 100 mg and 200 mg lactoferrin vaginal pessaries significantly decreased the occurrence of bacteria associated with BV, such as Gardnerella, Prevotella, and Lachnospira, and increased the occurrence of Lactobacillus species. The bacterial biota balance was maintained up to 2 weeks after treatment only in women treated with 200 mg lactoferrin pessaries.Conclusions: This study indicates that lactoferrin could be proposed as an alternative therapeutic approach for BV. Our data showed, for the first time, the dominance of Lactobacillus helveticus species during and after vaginal lactoferrin treatment.

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Origins of vaginal acidity: high d/l lactate ratio is consistent with bacteria being the primary source

Abstract: Our results thus support the hypothesis that vaginal bacteria, not epithelial cells, are the primary source of lactic acid in the vagina.

Cited by 429 publications

References 25 publications

Growth and lactic acid production by vaginal Lactobacillus acidophilus CRL 1259, and inhibition of uropathogenic Escherichia coli

Growth and lactic acid production by vaginal Lactobacillus acidophilus CRL 1259, and inhibition of uropathogenic Escherichia coli

Vaginal microbiome of reproductive-age women

Bacterial biota of women with bacterial vaginosis treated with lactoferrin: an open prospective randomized trial

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