Antagonistic activity of Lactiplantibacillus plantarum 6.2 extracted from cocoa fermentation and its supernatant on Gardnerella vaginalis

Abstract

Search for alternative methods for the treatment of bacterial vaginosis has been growing, and probiotics being among them. The most well-known probiotic microorganisms are lactobacilli, which are naturally present in the vaginal microenvironment. Cocoa fermentation is a source of lactic acid bacteria, with lactobacilli being the most prominent. The aim of this study was to evaluate the antagonistic activity of Lactiplantibacillus plantarum 6.2 a strain of lactobacilli isolated from cocoa fermentation, and its cell-free supernatant on Gardnerella vaginalis. It was shown that Lpb. plantarum 6.2 and its supernatant, used at three concentrations, i.e., 40, 20 and 10 mg/mL, have a strong antagonistic activity against G. vaginalis, with a probable action of proteinaceous bacteriocins; the activity was lost after heat treatment. The ability to exclude and displace G. vaginalis from the adhesion site to vaginal HMVII epithelial cells was also demonstrated by the lactobacilli and the supernatant, with the latter showing a bactericidal effect. Thus, the Lpb. plantarum 6.2 strain presents itself as a good probiotic with potential to be used not only as a therapeutic alternative for vaginosis but also as a complement to existing therapies.

Effect of Thermal Inactivation on Antioxidant, Anti-Inflammatory Activities and Chemical Profile of Postbiotics

“…Rocchetti et al found that the cell-free supernatant of L. plantarum also had similar immunomodulatory capacity compared with live bacteria [31]. RAMOS et al demonstrated that the cell-free supernatant of Lactiplantibacillus plantarum 6.2 excluded Gardnerella vaginalis from the adhesion site, and has good bactericidal effect like live bacteria [32]. Our study suggested that the antioxidant and anti-inflammatory capacity of the cell-free supernatant was lower than that of whole postbiotics at the same dose, but the biological activity of cell-free supernatants is still not negligible, especially in terms of anti-inflammatory capacity.…”