Probiotic and metabolic characterization of vaginal lactobacilli for a potential use in functional foods

The main aim of this work was to verify the metabolic and functional aptitude of 15 vaginal strains belonging to Lactobacillus crispatus, Lactobacillus gasseri, and Limosilactobacillus vaginalis (previously Lactobacillus vaginalis), already characterized for their technological and antimicrobial properties. In order to evaluate the metabolic profile of these vaginal strains, a phenotype microarray analysis was performed on them. Functional parameters such as hydrophobicity, auto-aggregation, deconjugation of bile salts, adhesion to an intestinal cell line (Caco-2), and a simulated digestion process were evaluated for these strains. A good number of these strains showed hydrophobicity values higher than 70%. Regarding the auto-aggregation assay, the most promising strains were L. crispatus BC9 and BC1, L. gasseri BC10 and BC14, and L. vaginalis BC17. Moreover, L. crispatus BC4, BC6, BC7, and BC8 were characterized by strong bile salts hydrolase activity (BHS). In addition, L. crispatus BC8 and L. vaginalis BC17 were characterized by a medium ability to adhere to Caco-2 cells. Data related to digestion process showed a strong ability of vaginal lactobacilli to withstand this stress. In conclusion, the data collected show the metabolic versatility and several exploitable functional properties of the investigated vaginal lactobacilli.