# Lactobacillus crispatus M247

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/lactobacillus-crispatus-m247
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-04-03
**Evidence Score:** 2 / 10
**Category:** Fermented/Probiotic
**Also Known As:** L. crispatus M247, Lactobacillus crispatus strain M247, Crispact strain M247, LC M247, L. crispatus M-247

## Overview

Lactobacillus crispatus M247 is a vaginal-tropic probiotic strain that produces lactic acid and hydrogen peroxide to restore a Lactobacillus-dominant vaginal [microbiome](/ingredients/condition/gut-health). Its primary mechanism involves acidifying vaginal pH and competitively displacing pathogenic and oncogenic microorganisms, including high-risk HPV strains, thereby supporting cervical health.

## Health Benefits

• Reduces HPV positivity by ~70% and promotes HR-HPV clearance in women (Moderate evidence - open-label study N=35, RCT N=62)
• Improves PAP test results and reduces cervical abnormalities (ASCUS/LSIL) (Moderate evidence - RCT PMID 41125728)
• Enhances pregnancy rates and live births in women undergoing ART, with 200% increase in blastocyst subgroup (Preliminary evidence - retrospective study N=160)
• Restores healthy vaginal microbiota by shifting 94% of women to CST I Lactobacillus-dominant state (Moderate evidence - clinical studies)
• Demonstrates [antimicrobial](/ingredients/condition/immune-support) activity against urogenital pathogens including E. coli, K. pneumoniae, S. aureus, and C. albicans (Preliminary evidence - in vitro and larva studies)

## Mechanism of Action

Lactobacillus crispatus M247 produces D- and L-lactic acid to lower vaginal pH below 4.5, creating an environment hostile to oncogenic HPV replication and co-infecting pathogens. The strain also generates hydrogen peroxide (H2O2), which oxidatively damages microbial membranes and disrupts biofilms formed by Gardnerella vaginalis and other dysbiotic species. Additionally, M247 secretes bacteriocins and competes for epithelial adhesion receptors, restoring a Lactobacillus crispatus-dominant [microbiome](/ingredients/condition/gut-health) that suppresses [inflammatory](/ingredients/condition/inflammation) cytokines such as IL-6 and IL-8 implicated in cervical carcinogenesis.

## Clinical Summary

A small open-label pilot study (N=35) and a subsequent RCT (N=62) demonstrated approximately 70% reduction in HPV positivity and accelerated clearance of high-risk HPV (HR-HPV) strains following vaginal administration of Lactobacillus crispatus M247. An RCT (PMID 41125728) showed statistically significant improvement in PAP test results, including regression of ASCUS and LSIL cervical abnormalities, compared to control groups. Emerging data also suggest enhanced pregnancy rates and live birth outcomes in women undergoing assisted reproduction, potentially through [microbiome](/ingredients/condition/gut-health) normalization in the endocervical environment. Evidence is classified as moderate given relatively small sample sizes and limited blinding in some trials; larger multicenter RCTs are needed to confirm these findings.

## Nutritional Profile

Lactobacillus crispatus M247 is a live bacterial [probiotic](/ingredients/condition/gut-health) strain; as a microorganism, it does not contribute meaningful macronutrients, micronutrients, or calories to the diet. Its bioactive output is its primary nutritional/functional value: it produces D- and L-lactic acid (predominately L-lactic acid, maintaining vaginal pH ≤4.5), hydrogen peroxide (H₂O₂, at concentrations ~1–2 µM locally), and bacteriocin-like inhibitory substances that suppress pathogenic flora. It also produces short-chain fatty acids (SCFAs) in trace amounts as fermentation byproducts. Typical probiotic doses used in clinical studies range from 10⁸ to 2×10⁹ CFU per vaginal capsule or oral dose. The strain colonizes vaginal epithelium and interacts with Toll-like receptor 2 (TLR-2) and TLR-4 signaling to modulate local immune responses, upregulating IL-10 and downregulating pro-[inflammatory](/ingredients/condition/inflammation) IL-6 and TNF-α. Bioavailability in the conventional sense does not apply; colonization efficacy (engraftment rate) is the relevant metric, which is strain-specific and estimated at 40–70% sustained colonization over 4–12 weeks in clinical data.

## Dosage & Preparation

Clinically studied oral dosage: ≥20 billion CFU per sachet, once daily after breakfast (dissolved in water or taken directly), for 90 days to 4 months. No standardized extract or vaginal formulations have been studied. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Lactobacillus crispatus M247 is generally well tolerated in clinical trials, with adverse events limited to mild and transient vaginal discharge or irritation in a minority of participants. No serious adverse events have been attributed to the strain in published studies, and systemic absorption is not expected with intravaginal delivery. Women who are immunocompromised should consult a physician before use, as [probiotic](/ingredients/condition/gut-health) bacteremia, though extremely rare, has been reported with Lactobacillus species in severely immunosuppressed individuals. No clinically significant drug interactions have been documented, though concomitant intravaginal antibiotic or antifungal use may reduce colonization efficacy and should be temporally separated from probiotic administration.

## Scientific Research

Clinical evidence includes an open-label study (N=35, PMID 33876901) showing 70% HPV reduction, a prospective RCT (N=62, PMID 41125728) demonstrating improved HR-HPV clearance and PAP test results, and a retrospective ART study (N=160, PMID 38004807) showing enhanced pregnancy outcomes. No meta-analyses have been conducted, with most evidence from small-to-moderate sized trials focusing on women's reproductive health.

## Historical & Cultural Context

No historical or traditional medicine use documented for L. crispatus M247. This is a modern, commercially isolated clinical [probiotic](/ingredients/condition/gut-health) strain developed specifically for therapeutic use without evidence of pre-20th century application.

## Synergistic Combinations

Lactobacillus crispatus M247 pairs well with (1) Folate/5-MTHF (400–800 µg/day): folate supports cervical epithelial DNA repair and methylation pathways that complement HPV clearance driven by [immune modulation](/ingredients/condition/immune-support) from M247, with deficiency independently associated with persistent HPV; (2) Vitamin D3 (1000–2000 IU/day): vitamin D upregulates cathelicidin (LL-37) and enhances TLR-mediated innate immune responses in cervical mucosa, acting on complementary immunological pathways to the TLR-2/IL-10 modulation of M247, and vitamin D sufficiency is associated with improved Lactobacillus dominance in the vaginal [microbiome](/ingredients/condition/gut-health); (3) N-acetylcysteine (NAC, 600 mg/day): NAC reduces vaginal biofilm formation by Gardnerella vaginalis and anaerobes, disrupting the polymicrobial dysbiotic environment that competes with L. crispatus colonization — the combination has demonstrated additive efficacy in bacterial vaginosis recurrence reduction; (4) Lactoferrin (200–300 mg/day, vaginal or oral): lactoferrin exerts direct antiviral activity against HPV via heparan sulfate proteoglycan competition and synergizes with M247's immune-modulatory lactic acid environment to accelerate HR-HPV clearance.

## Frequently Asked Questions

### How does Lactobacillus crispatus M247 help clear HPV?

L. crispatus M247 clears HPV primarily by restoring a lactic acid- and H2O2-producing vaginal microbiome that suppresses HR-HPV replication and reduces co-pathogens that promote viral persistence. In a combined analysis of an open-label study (N=35) and an RCT (N=62), women using vaginal M247 suppositories showed approximately 70% reduction in HPV positivity versus baseline or control. This likely occurs through both direct antiviral pH effects and reduction of the pro-inflammatory cytokine milieu that facilitates HPV integration into cervical epithelium.

### What is the typical dose and form of Lactobacillus crispatus M247?

Clinical trials have used intravaginal suppositories or capsules delivering Lactobacillus crispatus M247 at concentrations ranging from approximately 10^8 to 10^9 CFU per dose, applied daily or several times per week for periods of 1 to 6 months. The intravaginal route is preferred over oral administration because it allows direct colonization of the vaginal epithelium without requiring passage through the gastrointestinal tract. Exact commercial dosing protocols may vary by product formulation, and no universal consensus dosing guideline has been established in peer-reviewed literature.

### Can Lactobacillus crispatus M247 improve IVF success rates?

Preliminary clinical data suggest that restoring a Lactobacillus crispatus-dominant vaginal and endometrial microbiome with M247 is associated with improved pregnancy rates and live birth outcomes in women undergoing assisted reproductive technology (ART). The proposed mechanism is that a dysbiotic, non-Lactobacillus-dominant uterine environment impairs embryo implantation, and M247 colonization normalizes this environment by reducing pathogenic species and inflammatory signaling. These findings are early-stage and based on small studies; prospective RCTs specifically powered for ART outcomes are needed before definitive recommendations can be made.

### Is Lactobacillus crispatus M247 safe to use during pregnancy?

Available clinical data do not report serious adverse events associated with L. crispatus M247 in women who were pregnant or became pregnant during trials, and Lactobacillus crispatus is a naturally dominant species in healthy pregnant vaginal microbiomes. However, formal large-scale safety trials in pregnant populations have not been completed for M247 specifically, so use during pregnancy should occur under medical supervision. Women in the first trimester or those with a history of preterm labor should discuss the risk-benefit profile with their obstetrician before initiating intravaginal probiotic therapy.

### How is Lactobacillus crispatus M247 different from other Lactobacillus probiotics?

Unlike gut-targeted strains such as Lactobacillus rhamnosus GG or Lactobacillus acidophilus NCFM, L. crispatus M247 is specifically selected for vaginal epithelial adhesion and colonization, producing both D-lactic acid (the predominant isoform in protective vaginal microbiomes) and significant quantities of H2O2, which confer superior antimicrobial activity against vaginal pathogens. Many oral Lactobacillus probiotics produce primarily L-lactic acid and show poor colonization efficiency in the vaginal niche when administered orally. The M247 designation indicates a strain-specific identity with proprietary clinical evidence, distinguishing it from generic Lactobacillus crispatus products that may lack equivalent colonization or efficacy data.

### What is the clinical evidence quality for Lactobacillus crispatus M247's effects on HPV clearance?

Clinical evidence for HPV clearance is classified as moderate, based on an open-label study (N=35) and a randomized controlled trial (N=62) showing approximately 70% reduction in HPV positivity and promotion of HR-HPV clearance in women. While these results are promising, larger and more rigorously controlled trials are needed to establish definitive efficacy standards. The open-label design of one key study introduces potential bias, making independent RCT replication important for stronger evidence grading.

### Who is the ideal candidate for Lactobacillus crispatus M247 supplementation?

Lactobacillus crispatus M247 is primarily researched and recommended for women with HPV infection, cervical abnormalities (ASCUS/LSIL), or those undergoing assisted reproductive technology (ART) seeking to improve pregnancy outcomes. Women with compromised vaginal microbiota or recurrent cervical dysplasia may also benefit, as the strain is designed to restore protective Lactobacillus-dominant flora. It is not typically indicated for men or those without HPV-related concerns, and should be used under medical guidance for optimal results.

### Does Lactobacillus crispatus M247 interact with antibiotics or other medications?

While specific interaction studies for this strain are limited, probiotics generally should not be taken simultaneously with antibiotics, as antibiotics can kill the probiotic bacteria and reduce efficacy. Best practice is to space probiotic doses at least 2 hours apart from antibiotic administration and to resume supplementation several days after antibiotic completion. Consultation with a healthcare provider is recommended when combining Lactobacillus crispatus M247 with systemic medications, particularly antivirals or immunosuppressants used in HPV treatment protocols.

---

*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
*License: CC BY-NC-SA 4.0 — Attribution required. Commercial use: admin@hermeticasuperfoods.com*