Probiotic Lactobacillus sp. Strains Inhibit Growth, Adhesion, Biofilm Formation, and Gene Expression of Bacterial Vaginosis-Inducing Gardnerella vaginalis

Abstract

<i>Gardnerella vaginalis</i> contributes significantly to bacterial vaginosis, which causes an ecological imbalance in vaginal microbiota and presents with the depletion of <i>Lactobacillus</i> sp. <i>Lactobacillus</i> supplementation was reported to be an approach to treat bacterial vaginosis. We investigated the applicability of three <i>Lactobacillus</i> sp. strains (<i>Lactobacillus delbrueckii</i> DM8909, <i>Lactiplantibacillus plantarum</i> ATCC14917, and <i>Lactiplantibacillus plantarum</i> ZX27) based on their probiotic abilities in vitro. The three candidate <i>Lactobacillus</i> sp. strains for bacterial vaginosis therapy showed distinct properties in auto-aggregation ability, hydrophobicity, adhesion to cervical epithelial cells, and survivability in 0.01% hydrogen peroxide. <i>Lpb. plantarum</i> ZX27 showed a higher yield in producing short-chain fatty acids and lactic acid among the three candidate strains, and all three <i>Lactobacillus</i> sp. strains inhibited the growth and adhesion of <i>G. vaginalis</i>. Furthermore, we discovered that the culture supernatant of <i>Lactobacillus</i> sp. exhibited anti-biofilm activity against <i>G. vaginalis</i>. In particular, the <i>Lpb. plantarum</i> ZX27 supernatant treatment decreased the expression of genes related to virulence factors, adhesion, biofilm formation, metabolism, and antimicrobial resistance in biofilm-forming cells and suspended cells. Moreover, <i>Lactobacillus</i> sp. decreased the upregulated expression of interleukin-8 in HeLa cells induced by <i>G. vaginalis</i> or hydrogen peroxide. These results demonstrate the efficacy of <i>Lactobacillus</i> sp. application for treating bacterial vaginosis by limiting the growth, adhesion, biofilm formation, and virulence properties of <i>G. vaginalis</i>.