ArticleBMC microbiology2019
Vaginal pH measured in vivo: lactobacilli determine pH and lactic acid concentration.
Article in BMC microbiology, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 80 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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Who cites it
80 citing papers in PubMed, 2 syntheses or guidelines pooled it, 115 citations in OpenAlex.
- Feminine Intimate Hygiene: A Review of Healthy and Unhealthy Habits in Women.Medicina (Kaunas, Lithuania) · 2025Pooled it
- Lactic acid-containing products for bacterial vaginosis and their impact on the vaginal microbiota: A systematic review.PloS one · 2021Pooled it
- The cervicovaginal gut microbiota axis as a key determinant of systemic physiology.Gut microbes · 2026Review
- From Active Compound to Target Epithelium: Local Delivery, Preclinical Model Validity, and Clinical Endpoint Interpretation in Topical Therapy for HPV-Associated Lower Genital Tract Disease-A Narrative Review.Journal of clinical medicine · 2026Review
- Glycerol Monolaurate Supplementation in Extruded Diets Enhances Immune Function and Antioxidant Capacity and Alters the Gut Microbiota and Fecal Metabolome in Cats.Antioxidants (Basel, Switzerland) · 2026Article
- The Impact of the Vaginal Microbiome and Microbial Metabolites on HIV Transmission at the Female Reproductive Tract Epithelial Barrier.American journal of reproductive immunology (New York, N.Y. : 1989) · 2026Review
- Maternal and infant gut microbiome.iMeta · 2026Review
- Elucidating the Staphylococcus aureus TSST-1 Regulatory Network as a Response to Vaginal pH.Molecular microbiology · 2026Article
- Preclinical Pharmacokinetics of a Triple-Combination Intravaginal Ring for HIV Prevention.Pharmaceutics · 2026Article
- Multiomic analysis reveals that polyamines alter G. vaginalis-induced cervicovaginal epithelial cell dysfunction.Research square · 2026Article
- Acid-dependent beta-lactam resistance inmBio · 2026Article
- Intrinsically disordered protein coating for oral delivery of peptide drugs.Cell biomaterials · 2026Article
- Unraveling the relationship between the vaginal microbiome and return to estrus in post-weaning sows.BMC veterinary research · 2026Article
- Induction of Human β-Defensin-2 by VaginalOpen forum infectious diseases · 2026Article
- Lactic Acid-Loaded Hydrogels for Post-Episiotomy Wound Healing: Microenvironment Engineering and Regenerative Strategies-A Narrative Review.Molecules (Basel, Switzerland) · 2026Review
- Genetically Modified Lactic Acid Bacteria: a Promising Mucosal Delivery Vector for Vaccines.Probiotics and antimicrobial proteins · 2026Review
- Clinical analysis of association between vaginal microbiota indicators and HPV infection.Frontiers in global women's health · 2026Article
- Targeting vaginal dysbiosis: prospects for the application of live biotherapeutics products.Frontiers in microbiology · 2026Review
- Preliminary investigation of changes in pathogen presence in the vaginal microbiome in association with age.Iranian journal of microbiology · 2025Article
- Lactic acid in the vaginal milieu modulates theVirulence · 2025Article
20 more citing papers are in PubMed but not listed here.
Corrections and comments
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Authors and funding
3 authors at 3 institutions in 1 country.
Funding
Abstract
backgroundLactic acid (protonated lactate) has broad antimicrobial activity. Vaginal lactobacilli produce lactic acid, and are known to confer protection against reproductive tract infections when they are predominant in the vaginal microbiota. Using novel ex vivo methods, we showed that cervicovaginal fluid (CVF) from women with a predominantly lactobacilli-morphotype microbiota contains significantly more lactic acid than previously thought, sufficient to inactivate reproductive tract pathogens. Here, we measured vaginal pH in vivo in 20 women with a predominantly lactobacilli-morphotype (low Nugent score) microbiota. We also investigated the in vitro production of protons (as hydrogen ions) and lactate by vaginal lactobacilli.
resultsThe average vaginal pH in these women was 3.80 ± 0.20, and the average lactate concentration was 0.79% ± 0.22% w/v, with pH and lactate concentration tightly correlated for each sample. In vitro, lactobacilli cultured from these CVF samples reached an average pH of 3.92 ± 0.22, but the average lactate concentration was only 0.14% ± 0.06% w/v, approximately five-fold less than in the corresponding CVF samples. When the pH of the cultures was raised, lactate and hydrogen ion production resumed, indicating that production of lactate and hydrogen ions by vaginal lactobacilli is limited primarily by their sensitivity to hydrogen ion concentration (low pH) not lactate concentration.
conclusionsSome vaginal lactobacilli cultures have a lower limiting pH than others, and limiting pHs in vitro showed good correlation with pHs measured in vivo. The limiting pH of the lactobacilli predominant in a woman's vaginal microbiota seems critical in determining the concentration of antimicrobial lactic acid protecting her.
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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.