Inhibitory effect of Lactobacillus gasseri CCFM1201 on Gardnerella vaginalis in mice with bacterial vaginosis

Gardnerella vaginalis is the core pathogen of bacterial vaginosis (BV), the most common vaginal infection in women. G. vaginalis exerts pathogenicity through various factors, such as biofilm formation and the local host immune response stimulation. Therefore, this study aimed to evaluate the inhibitory effect of Lactobacillus gasseri CCFM1201 on G. vaginalis using experimental BV models. We evaluated L. gasseri in vitro to inhibit pathogen biofilm formation and adhesion capacity in HeLa cells using crystal violet staining. Further in vivo studies were conducted to assess the inhibitory effects of L. gasseri CCFM1201 on BV induced by G. vaginalis. L. gasseri exhibited strain-specific adhesion and inhibition of pathogen biofilm formation in vitro. L. gasseri CCFM1201 significantly reduced G. vaginalis in mice (p < 0.05), inhibited sialidase activity, modulated tumor necrosis factor-α and interleukin-1β expression, and reduced myeloperoxidase activity (p < 0.05). Histopathological examination indicated that L. gasseri CCFM1201 improved inflammatory cell infiltration of vaginal tissue and restored its structure. Vaginal epithelial cell exfoliation, the main clinical feature of BV, was significantly improved by L. gasseri CCFM1201 intervention (p < 0.05). Thus, L. gasseri CCFM1201 is a potential candidate for treating G. vaginalis-induced vaginal diseases.