Exploring of probiotic potential vaginal lactobacillus isolates from healthy women against Gardnerella vaginalis and Caenorhabditis elegans model testing

Abstract

Aim: Lactobacillus species are the dominant microorganisms in the vaginal microbiota of healthy women and play an important role in the defence against pathogens.This study aimed to evaluate probiotic potential of Lactiplantibacillus plantarum strain P1 isolated from healthy woman's vaginal discharge for its further utilization as a promising candidate strain in the treatment of bacterial vaginosis caused by Gardnerella vaginalis.Methods and Results: Ten lactobacilli strains from a woman's vaginal discharge were evaluated for their probiotic potential, including growth capacity at different pH levels (pH 3.5-4.5), acid production, hydrogen peroxide production capacity, antibacterial activity and susceptibility to antibiotics. Moreover, in vitro safety assay haemolytic activity and mutagenicity were investigated for safety assessment. In vivo Caenorhabditis elegans infection model was used to investigate the anti-infection effect of selected isolates. We found that lactobacilli strain P1 showed strong growth ability in low acid environment, produced acid, hydrogen peroxide, had the strongest antibacterial activity against G. vaginalis and was highly susceptible to the tested antibiotics. When assayed for the safety, strain P1 showed no haemolytic activity and had no effect of mutagenicity. Moreover, P1 significantly increased the lifespan of C. elegans against G. vaginalis infection. Combined with the results of 16S rRNA gene sequencing, morphological and physiological characteristic, the strain was identified as Lactiplantibacillus plantarum. Conclusion:Lactiplantibacillus plantarum strain P1 proves to be a promising candidate strain in the treatment of bacterial vaginosis caused by G. vaginalis.Significance and Impact of the Study: Conventional antibiotic therapy for bacterial vaginosis has led to the accelerated process of bacterial drug resistance. Probiotics are potentially an alternative method for bacterial vaginosis therapy. This finding provides bacterial resources for keeping pathogens away from the vagina. We believe L. plantarum P1 may be used as vaginal probiotics and be useful to prevent or treat bacterial vaginitis.

Collagen-Based Ovule Therapy Reduces Inflammation and Improve Cervical Epithelialization in Patients with Fungal, Viral, and Bacterial Cervico-Vaginitis

“…In the absence of this barrier, during a period of active cell replication such as that occurring in the presence of immature metaplasia or cervical ectropion, in a state of cellular inflammation, and in the presence of contributing factors such as altered vaginal pH, various pathogens can replicate more easily and disrupt the normal resident microbiota [ 11 , 12 ]. Our results align with previous research highlighting the importance of a balanced vulvo-vaginal environment in maintaining vaginal health [ 10 , 13 , 14 , 15 , 16 , 17 ]. These findings are consistent with the emerging understanding that preserving a stable vaginal microbiome may be more beneficial than the use of antibiotics or antiviral agents alone in managing various cervico-vaginal infections.…”

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

“…Similarly, in mouse vaginal tissue lysates, a combination of five lactobacilli strains can greatly inhibit G. vaginalis proliferation and considerably lower myeloperoxidase activity, pro-inflammatory cytokine levels (TNF-α, IL-1β, and IL-6), and nitric oxide levels ( Choi et al., 2022 ). In experiments using a Caenorhabditis elegans model, L. plantarum strain P1 has shown potent antibacterial action against G. vaginalis and considerably prolonged the lifespan of C. elegans after exposure to infection agents ( Li et al., 2022 ).…”

Synthetic bacterial consortia transplantation for the treatment of Gardnerella vaginalis-induced bacterial vaginosis in mice

“…Perhaps because VMT is introduced into the vagina as a whole system, allowing the microbiota to maintain better stability, and VMT contains bacteria that are not present in the synthetic preparation. However, the bacterial strains we selected for SBCT were able to produce natural antibacterial products such as hydrogen peroxide and lactic acid to resist pathogenic bacteria [ 30 ]. Previous studies reported that oral or vaginal administration of a Lactobacilli mixture could attenuate GV-inoculated mice by regulating the innate and adaptive immune responses [ 20 ].…”