Lactobacillus crispatus M247

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

Origin & History

Lactobacillus crispatus M247 is a specific probiotic strain isolated from the commercial vaginal probiotic product Crispact® by PharmExtracta S.p.A. (Pontenure, Italy), originally derived from human vaginal microbiota. It is cultured and provided as live bacteria or cell-free supernatant (CFS), with no plant source or chemical extraction involved.

Historical & Cultural Context

No historical or traditional medicine use documented for L. crispatus M247. This is a modern, commercially isolated clinical probiotic strain developed specifically for therapeutic use without evidence of pre-20th century application.

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 activity against urogenital pathogens including E. coli, K. pneumoniae, S. aureus, and C. albicans (Preliminary evidence - in vitro and larva studies)

How It Works

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 that suppresses inflammatory cytokines such as IL-6 and IL-8 implicated in cervical carcinogenesis.

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.

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 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 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 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.

Preparation & Dosage

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.

Synergy & Pairings

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 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; (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.

Safety & 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 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.