ArticleInfection and immunity1999
Acid production by vaginal flora in vitro is consistent with the rate and extent of vaginal acidification.
Article in Infection and immunity, 1999. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 177 papers, 2 of them syntheses that pooled it.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
177 citing papers in PubMed, 2 syntheses or guidelines pooled it, 375 citations in OpenAlex.
- Lactic acid-containing products for bacterial vaginosis and their impact on the vaginal microbiota: A systematic review.PloS one · 2021Pooled it
- The epidemiology of bacterial vaginosis in relation to sexual behaviour.BMC infectious diseases · 2010Pooled it
- Effectiveness and tolerability of lactic acid vaginal gel compared to oral metronidazole in the treatment of acute symptomatic bacterial vaginosis: a multicenter, randomized-controlled, head-to-head pilot study.BMC women's health · 2025Trial
- Trial
- Exploring potential of vaginal Lactobacillus isolates from South African women for enhancing treatment for bacterial vaginosis.PLoS pathogens · 2020Trial
- Comparative phase I randomized open-label pilot clinical trial of GynophilusEuropean journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology · 2018Trial
- Bacterial vaginosis and the risk of trichomonas vaginalis acquisition among HIV-1-negative women.Sexually transmitted diseases · 2014Trial
- Improvements of vaginal atrophy without systemic side effects after topical application of Pueraria mirifica, a phytoestrogen-rich herb, in postmenopausal cynomolgus macaques.The Journal of reproduction and development · 2014Trial
- Trial
- Changes in the Vaginal Microenvironment as Related to Frequency of Pessary Removal.Female pelvic medicine & reconstructive surgeryTrial
- The cervicovaginal gut microbiota axis as a key determinant of systemic physiology.Gut microbes · 2026Review
- Complement protein concentrations and activity in human cervical mucus.bioRxiv : the preprint server for biology · 2026Article
- Spondylodiscitis Following Oxygen-Ozone Therapy: A Case Report ofDiseases (Basel, Switzerland) · 2026Review
- Interactions betweenInfection and immunity · 2026Article
- Vaginal microbiota in assisted reproduction: determinants, dynamics, and impact on clinical outcomes.Frontiers in microbiology · 2026Review
- The vital role of Lactobacillus sp. in vaginal health: Implications for enhanced prophylactic research.Probiotics and antimicrobial proteins · 2026Review
- The microbiota-host metabolic axis in cervical cancer: from homeostatic disruption to mechanisms of therapy resistance.Frontiers in cellular and infection microbiology · 2026Review
- Vaginal microbiome structure in pregnancy and host factors predict preterm birth: Results from the ECHO Cohort.Annals of epidemiology · 2025Article
- Disrupted Cervicovaginal Microbiota: Its Role inInternational journal of molecular sciences · 2025Review
- Vaginal epithelial estrogen receptor α coordinates glycogen deposition, microbial stability, and pH regulation in mice.bioRxiv : the preprint server for biology · 2025Article
117 more citing papers are in PubMed but not listed here.
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Authors and funding
5 authors at 2 institutions in 1 country.
Funding
Abstract
Perinatally, and between menarche and menopause, increased levels of estrogen cause large amounts of glycogen to be deposited in the vaginal epithelium. During these times, the anaerobic metabolism of the glycogen, by the epithelial cells themselves and/or by vaginal flora, causes the vagina to become acidic (pH approximately 4). This study was designed to test whether the characteristics of acid production by vaginal flora in vitro can account for vaginal acidity. Eight vaginal Lactobacillus isolates from four species-L. gasseri, L. vaginalis, L. crispatus, and L. jensenii-acidified their growth medium to an asymptotic pH (3.2 to 4.8) that matches the range seen in the Lactobacillus-dominated human vagina (pH 3.6 to 4.5 in most women) (B. Andersch, L. Forssman, K. Lincoln, and P. Torstensson, Gynecol. Obstet. Investig. 21:19-25, 1986; L. Cohen, Br. J. Vener. Dis. 45:241-246, 1969; J. Paavonen, Scand. J. Infect. Dis. Suppl. 40:31-35, 1983; C. Tevi-Bénissan, L. Bélec, M. Lévy, V. Schneider-Fauveau, A. Si Mohamed, M.-C. Hallouin, M. Matta, and G. Grésenguet, Clin. Diagn. Lab. Immunol. 4:367-374, 1997). During exponential growth, all of these Lactobacillus species acidified their growth medium at rates on the order of 10(6) protons/bacterium/s. Such rates, combined with an estimate of the total number of lactobacilli in the vagina, suggest that vaginal lactobacilli could reacidify the vagina at the rate observed postcoitally following neutralization by the male ejaculate (W. H. Masters and V. E. Johnson, Human sexual response, p. 93, 1966). During bacterial vaginosis (BV), there is a loss of vaginal acidity, and the vaginal pH rises to >4.5. This correlates with a loss of lactobacilli and an overgrowth of diverse bacteria. Three BV-associated bacteria, Gardnerella vaginalis, Prevotella bivia, and Peptostreptococcus anaerobius, acidified their growth medium to an asymptotic pH (4.7 to 6.0) consistent with the characteristic elevated vaginal pH associated with BV. Together, these observations are consistent with vaginal flora, rather than epithelial cells, playing a primary role in creating the acidity of the vagina.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.