Use of probiotic lactobacilli in the treatment of vaginal infections: In vitro and in vivo investigations

Abstract

The vaginal microbiome is a distinct component of the human microbiome that is colonized by a wide variety of microorganisms. Lactobacilli are the most frequently identified microorganisms in the healthy human vagina. These Gram-positive bacilli can acidify the vaginal microenvironment, inhibit the proliferation of other pathogenic microorganisms, and promote the maintenance of a eubiotic vaginal microbiome. However, a vaginal flora with a reduced proportion or abundance of lactobacilli is associated with various vaginal infections that have been linked to serious health consequences such as infertility, preterm birth, pelvic inflammatory disease, premature rupture of membranes, and miscarriage. Due to their "Generally Recognized as Safe" classification and critical role in vaginal health, probiotic lactobacilli have been widely used as an alternative or adjunct to traditional antibiotic therapy for the treatment of vaginal infections and restoration of the vaginal microbiome. This review focuses on the significant role of probiotic lactobacilli in the vaginal microenvironment and discusses the use of probiotic lactobacilli in the treatment of female vaginal infections in vitro and in vivo.

Keywords: lactobacilli; probiotic; treatment; vaginal infections; vaginal microbiome.

Figure 1

The approaches to treating various vaginal infections. Pathogens associated with BV, VVC, AV, viral infections, and other STIs can cause damage to vaginal epithelial cells and mucosa. Approaches including antibiotics, probiotics, and antibiotics plus probiotics could affect therapeutic efficacy.

Figure 2

Two different routes for probiotic lactobacilli administration. (A) Oral administration. Probiotic lactobacilli taken orally must travel via the mouth, stomach, intestines, and colon before reaching the vagina via skin contact in the perineum. The probiotics are delivered to the vagina in approximately seven days. (B) Intravaginal administration. Probiotic lactobacilli can also be administered intravaginally using external devices. Within 2–3 days, lactobacillus strains manifest their effects.