Lactobacilli extracellular vesicles: potential postbiotics to support the vaginal microbiota homeostasis

Bibliographic Details
Title: Lactobacilli extracellular vesicles: potential postbiotics to support the vaginal microbiota homeostasis
Authors: Vanessa Croatti, Carola Parolin, Barbara Giordani, Claudio Foschi, Stefano Fedi, Beatrice Vitali
Source: Microbial Cell Factories, Vol 21, Iss 1, Pp 1-11 (2022)
Publisher Information: BMC, 2022.
Publication Year: 2022
Collection: LCC:Microbiology
Subject Terms: Extracellular vesicles, Lactobacillus, Adhesion, Postbiotics, Vaginal homeostasis, Microbiology, QR1-502
More Details: Abstract Background Lactobacillus species dominate the vaginal microflora performing a first-line defense against vaginal infections. Extracellular vesicles (EVs) released by lactobacilli are considered mediators of their beneficial effects affecting cellular communication, homeostasis, microbial balance, and host immune system pathways. Up to now, very little is known about the role played by Lactobacillus EVs in the vaginal microenvironment, and mechanisms of action remain poorly understood. Results Here, we hypothesized that EVs can mediate lactobacilli beneficial effects to the host by modulating the vaginal microbiota colonization. We recovered and characterized EVs produced by two vaginal strains, namely Lactobacillus crispatus BC5 and Lactobacillus gasseri BC12. EVs were isolated by ultracentrifugation and physically characterized by Nanoparticle Tracking Analysis (NTA) and Dynamic Light Scattering (DLS). EVs protein and nucleic acids (DNA and RNA) content was also evaluated. We explored the role of EVs on bacterial adhesion and colonization, using a cervical cell line (HeLa) as an in vitro model. Specifically, we evaluated the effect of EVs on the adhesion of both vaginal beneficial lactobacilli and opportunistic pathogens (i.e., Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae, and Enterococcus faecalis). We demonstrated that EVs from L. crispatus BC5 and L. gasseri BC12 significantly enhanced the cellular adhesion of all tested lactobacilli, reaching the maximum stimulation effect on strains belonging to L. crispatus species (335% and 269% of average adhesion, respectively). At the same time, EVs reduced the adhesion of all tested pathogens, being EVs from L. gasseri BC12 the most efficient. Conclusions Our observations suggest for the first time that EVs released by symbiotic Lactobacillus strains favor healthy vaginal homeostasis by supporting the colonization of beneficial species and preventing pathogens attachment. This study reinforces the concept of EVs as valid postbiotics and opens the perspective of developing postbiotics from vaginal strains to maintain microbiota homeostasis and promote women’s health.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1475-2859
Relation: https://doaj.org/toc/1475-2859
DOI: 10.1186/s12934-022-01963-6
Access URL: https://doaj.org/article/a799a4f5d9c94a479acdbbb908423639
Accession Number: edsdoj.799a4f5d9c94a479acdbbb908423639
Database: Directory of Open Access Journals
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More Details
ISSN:14752859
DOI:10.1186/s12934-022-01963-6
Published in:Microbial Cell Factories
Language:English