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Lcr6.0
L. crispatus CTV-05 Research
Mostly mechanism / observational
77 peer-reviewed studies
What the evidence says
Mostly mechanism / observational
Most L. crispatus CTV-05 studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from high-quality meta-analyses and randomised trials published 2009–2026 with a typical study size of 61 participants.
Based on 77 studies · 6 meta-analyses · 16 RCTs · 650 total participants
Confidence
High confidence
By outcome
Vaginal colonisation & microbiome
Mostly mechanism / observational43 studies
Bacterial vaginosis
Mostly mechanism / observational25 studies
Pregnancy & preterm birth
Mostly mechanism / observational18 studies
Genital inflammation & immunology
Mostly mechanism / observational16 studies
Urinary tract infection
Mostly mechanism / observational8 studies
Safety & local tolerance
Too few graded studies7 studies
Active research area
61 studies in the last 5 years · Latest meta-analysis: 2024
200920172026
1Meta-Analysis2023
In plain English: We believe future studies of the vaginal microbiome and PTB will benefit from a focus on earlier preterm births and improved reporting of specific patient metadata shown to influence the vaginal microbiome and/or birth outcomes.
Huang C et al. · BMC biology (2023)
We believe future studies of the vaginal microbiome and PTB will benefit from a focus on earlier preterm births and improved reporting of specific patient metadata shown to influence the vaginal microbiome and/or birth outcomes.
In plain English: Future studies employing metagenomic sequencing may help identify biomarkers for early pre-cancerous lesions and clarify the role of vaginal microbiota in persistent HPV infection and cervical dysplasia.
Žukienė G et al. · International journal of molecular sciences (2025)
Progression from HPV infection to cervical lesions and cancer was associated with a reduction in Lactobacillus species (particularly Lactobacillus crispatus) and an enrichment of anaerobic and pathogenic species, especially Gardnerella vaginalis.
Heterogeneous enriched metabolic pathways were also identified, indicating functional shifts during lesion progression.
As most studies were conducted in Asia, further research in diverse regions is needed to improve the generalizability of findings.
In plain English: Further studies are necessary to identify the exact role of this intriguing species in vaginal health and diseases.
Zheng N et al. · Frontiers in cellular and infection microbiology (2021)
It is not only commonly present in the healthy vagina but quite often recovered in high numbers in bacterial vaginosis (BV).
Increasing evidence suggests that L. iners is a transitional species that colonizes after the vaginal environment is disturbed and offers overall less protection against vaginal dysbiosis and, subsequently, leads to BV, sexually transmitted infections, and adverse pregnancy outcomes.
Accordingly, under certain conditions, L. iners is a genuine vaginal symbiont, but it also seems to be an opportunistic pathogen.
In plain English: Our work illustrates deleterious effects on the vaginal environment induced by Cu-IUD initiation, which may adversely impact sexual and reproductive health.
Brown BP et al. · Nature communications (2023)
Total bacterial loads of women using Cu-IUD increase 5.5 fold after six months, predominantly driven by increases in the concentrations of several inflammatory anaerobes.
Furthermore, growth of L. crispatus (MV-1A-US) is inhibited by Cu2+ ions below biologically relevant concentrations, in vitro.
Our work illustrates deleterious effects on the vaginal environment induced by Cu-IUD initiation, which may adversely impact sexual and reproductive health.
In plain English: Prospective tubal microbiome studies are warranted.
Vitale SG et al. · International journal of molecular sciences (2021)
We failed to identify descriptive or comparative studies regarding tubal microbiome.
The microbiome of the genital tract plays a pivotal role in fertility, also in case of ARTs.
The standardization of the sampling methods and investigations approaches is warranted to stratify the fertility potential and its subsequent treatment.
In plain English: These findings position the vaginal microbiome not as a passive bystander, but as an active determinant of HPV-driven carcinogenesis and underscore its diagnostic and therapeutic potential in cervical cancer prevention.
Bautista J et al. · Frontiers in cellular and infection microbiology (2025)
First, community state type IV (CST IV) microbiota strongly predict persistent HR-HPV infection and progression to high-grade lesions, highlighting their potential as non-invasive biomarkers for early risk stratification.
Second, cervicovaginal dysbiosis alters mucosal immunity and promotes epigenetic reprogramming of both host and viral genomes, facilitating immune evasion and oncogenesis.
Third, restoring Lactobacillus dominance through probiotics or microbial engineering holds translational promise for enhancing HPV vaccine efficacy and reducing cervical cancer burden.
In plain English: Younger women were more likely to have a higher-risk polymicrobial microbiome suggesting that vaginal microbiota are contributing to increased HIV-1 susceptibility in this group.
Wang Y et al. · Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2023)
Four microbiome types were identified based on predominant taxa, including Lactobacillus crispatus (CST-LC, 12.2%), Lactobacillus iners (CST-LI, 43.6%), Gardnerella vaginalis (CST-GV, 26.6%), or polymicrobial (CST-PM, 15.1%).
The HIV incidence rate of women with CST-PM microbiome was 7.19-fold higher compared to women with CST-LC (hazard ratio [HR], 7.19 [95% CI, 2.11-24.5], P = .00162), which was also consistent in women aged 20-24 years (HR, 4.90 [95% CI, 1.10-21.9], P = .0375).
Younger women were more likely to have a higher-risk polymicrobial microbiome suggesting that vaginal microbiota are contributing to increased HIV-1 susceptibility in this group.
In plain English: Special interest has been given to how the use of probiotics, diet intake, and use of hormone replacement therapies (HRTs) can potentially impact vaginal microbiota composition.
Barrientos-Durán A et al. · Nutrients (2020)
There is a consensus that vaginal flora is grouped into a restricted number of communities, although the structure of the community is constantly changing.
Certain Community-Sate Types (CSTs) are more associated with poor reproductive outcomes and sexually transmitted diseases (STDs) meanwhile, CSTs dominated by Lactobacillus species-particularly Lactobacillus crispatus-are more related to vaginal health.
In this work, we have reviewed how modifiable and non-modifiable factors may affect normal vaginal microbiota homeostasis-including sexual behavior, race or ethnicity, and hygiene.
In plain English: Vaginal longitudinal CST patterns over 18 months could be clustered into three main groups of trajectories.
Tamarelle J et al. · European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology (2024)
At baseline, 11.2% of participants had a CST IV, 40.5% a CST I (Lactobacillus crispatus-dominated), and 38.1% a CST III (Lactobacillus iners-dominated).
Over the study period, 32.0% participants displayed a stable CST trajectory.
Vaginal longitudinal CST patterns over 18 months could be clustered into three main groups of trajectories.
In plain English: Further studies should focus on demonstrating a causal relationship and identifying interventions to reduce the risk of preterm birth associated with changes in the vaginal microbiota.
Ferrante M et al. · European journal of obstetrics, gynecology, and reproductive biology (2025)
An increase in cytokines (IL-1β, IL-6, and MIP-1β) and a decrease in β-defensin-2 values also seem to influence the preterm birth onset.
In summary, we identified multiple vaginal microbiota that were associated with changes in the risk of preterm birth.
Carter KA et al. · Sexually transmitted diseases (2023)
Six Ct studies were included in meta-analysis, which showed L. iners -dominated microbiotas were associated with 3.4-fold higher odds of Ct compared with L. crispatus -dominated microbiotas (95% confidence interval, 2.1-5.4).
Three BV studies were included in meta-analysis, which indicated L. iners -dominated microbiotas were associated with 2.1-fold higher prevalence of BV compared with L. crispatus -dominated microbiotas (95% confidence interval, 0.9-4.9).
Evidence was too sparse to perform meta-analysis for the remaining outcomes.
In plain English: A political economy analysis will explore regulatory environments for menstrual products, and findings will be disseminated through policy briefs, stakeholder networks, academic publications and conferences.
In plain English: Our network meta-analysis supports the microbiome being predictive of preterm birth, where low abundance of lactobacilli is associated with the highest risk, and L. crispatus dominance the lowest.
Gudnadottir U et al. · Scientific reports (2022)
A (network) meta-analysis was conducted, presenting pooled odds ratios (OR) and 95% confidence intervals (CI); and weighted proportions and 95% CI.
Women presenting with "low-lactobacilli" vaginal microbiome were at increased risk (OR 1.69, 95% CI 1.15-2.49) for delivering preterm compared to Lactobacillus crispatus dominant women.
All 17 studies were published between 2014 and 2021 and included 38-539 pregnancies and 8-107 preterm births.
In plain English: This review integrates functional ecology, longitudinal clinical evidence, immunological and metabolic mechanisms, and translational implications, highlighting opportunities for microbiome-informed risk stratification and adjunctive interventions, as well as key gaps requiring standardized longitudinal multi-omics and rigorously designed clinical trials.
Suárez-Rico DO et al. · International journal of molecular sciences (2026)
Lactobacillus-dominant community states, particularly those enriched in Lactobacillus crispatus, are generally associated with lower pH, regulated inflammatory signaling, stronger barrier function, and a higher likelihood of HPV clearance.
Importantly, the interaction is bidirectional: hrHPV can remodel the microenvironment by suppressing host defense peptides and perturbing mucosal barriers, thereby reducing Lactobacillus fitness and reinforcing dysbiosis in a feed-forward loop that favors persistence and oncogenic progression.
In plain English: Conclusions: Our study demonstrated that the abundance of Lactobacillus and the four dominant individual species (L. crispatus, L. jensenii, L. iners, and L. gasseri) were significantly and negatively associated with the PTB risk.
Zhou Q et al. · Journal of women's health (2002) (2024)
Objective: With a global incidence of more than 10%, preterm birth (PTB) remains a significant concern.
The risk of PTB was determined by calculating odds ratios (ORs) with 95% confidence intervals (CIs).
The findings revealed a significant negative correlation between higher Lactobacillus abundance and the PTB risk (OR = 0.49, 95% CI: 0.29-0.84, p = 0.009 < 0.05).
In plain English: Species-level and site-specific reproductive tract microbiota profiles appear to better predict assisted reproductive technology outcomes than diversity measures alone.
Ma G, Zeng R, Cai R, He B, Han J, Gao R, Qin L. · BMC pregnancy and childbirth (2026)
Longer-term or individualized probiotic regimens appeared to increase Lactobacillus abundance and were associated with improved reproductive outcomes, whereas short-term interventions demonstrated minimal benefit.
Conclusion Species-level and site-specific reproductive tract microbiota profiles appear to better predict assisted reproductive technology outcomes than diversity measures alone.
Personalized or longer-duration probiotic strategies may hold therapeutic potential; however, current evidence remains limited and heterogeneous.
In plain English: The identification of 42 unique bacteria and their enrichment in cervical carcinogenesis can guide future cervicovaginal microbiome research to better inform cervical cancer prevention strategies in Latinas.
Mancilla V et al. · Journal of epidemiology and global health (2024)
The identification of 42 unique bacteria and their enrichment in cervical carcinogenesis can guide future cervicovaginal microbiome research to better inform cervical cancer prevention strategies in Latinas.