Antimicrobial and Prebiotic Activity of Lactoferrin in the Female Reproductive Tract: A Comprehensive Review Original paper

What was reviewed?

This review examined existing literature on the antimicrobial and prebiotic roles of lactoferrin (LF) in the female reproductive tract, integrating data from in vitro, in vivo, and clinical studies. It emphasized LF’s dual functionality: its ability to combat pathogenic microorganisms and its capacity to support beneficial vaginal microbiota, particularly Lactobacillus species.

Who was reviewed?

The review synthesized findings from studies involving human participants, animal models (notably mice and rats), and various probiotic bacterial strains. It focused on healthy women, women with dysbiosis-associated infections (e.g., bacterial vaginosis, vulvovaginal candidiasis, chlamydiosis), and pregnant individuals. The cited research included diverse ethnic populations, particularly regarding vaginal microbiota composition and probiotic strain efficacy.

What were the most important findings?

Lactoferrin acts as a selective antimicrobial agent in the female genital tract. It inhibits the growth of pathogens such as Gardnerella vaginalis, Atopobium vaginae, Escherichia coli, and Candida albicans through mechanisms including iron sequestration, membrane destabilization, biofilm inhibition, and synergistic interaction with immune mediators. Simultaneously, LF supports the growth and biofilm formation of beneficial bacteria such as Lactobacillus acidophilus, L. rhamnosus, and L. crispatus, helping restore eubiosis. It enhances adhesion and colonization of probiotic strains and may be enzymatically processed by probiotics into more active peptides like lactoferricin.

The review also highlights how LF modulates immune responses by suppressing pro-inflammatory cytokines (e.g., IL-6, IL-17, IL-8) and enhancing anti-inflammatory mediators, particularly in infections like C. trachomatis. Importantly, LF’s influence on microbiome composition is estrogen-dependent, with higher concentrations observed in the proliferative phase of the menstrual cycle. LF’s prebiotic benefit becomes especially relevant in combination with probiotics, forming synbiotic formulations that show enhanced clinical efficacy in reducing infections and promoting vaginal microbial balance.

What are the implications of this review?

Lactoferrin presents as a promising non-antibiotic intervention for female reproductive tract health, offering dual-action antimicrobial and prebiotic benefits. Its ability to suppress infections while promoting Lactobacillus-dominant eubiosis supports its integration into microbiome-focused gynecological therapies, including treatment of recurrent infections and pregnancy-associated complications. Moreover, its safety, hormone-responsive behavior, and synergistic role with probiotics make it highly suitable for use in synbiotic formulations, especially in populations vulnerable to dysbiosis, such as pregnant or immunocompromised individuals. Clinicians should consider LF as a candidate for adjunctive therapy or preventative care in microbiome-sensitive conditions of the female genital tract.