Aragón, AlbertoJurado Escobar, RubénJara Pérez, JosuéRodríguez Gómez, Juan MiguelOrgaz Martín, Belén2024-04-162024-04-162024-03-16: Aragón, A.; Jurado, R.; Jara, J.; Rodríguez, J.M.; Orgaz, B. Investigating the Metabolism of Estrogens in Ligilactobacillus salivarius Strains Isolated from Human Milk and Vaginal Microbiota. Nutrients 2024, 16, 861. https://doi.org/ 10.3390/nu1606086110.3390/nu16060861https://hdl.handle.net/20.500.14352/103155This article belongs to the Special Issue Probiotics and Homeostasis: How Probiotics Interact with Digestive Systems to Participate in Human Health Author contributions: Conceptualization, B.O. and J.M.R.; methodology, data analysis and writing—original draft preparation A.A., R.J. and J.J.; writing—review and edit, J.M.R. and B.O.; supervision, B.O.; funding acquisition, J.M.R. and B.O. All authors have read and agreed to the published version of the manuscript.The interplay between enterohepatic circulation and the gut microbiota is the main driver determining systemic levels of estrogens and their metabolites. Nevertheless, the role of potentially probiotic microorganisms in estrogen metabolism has not been investigated so far. In this work, we have explored the ability of six Ligilactobacillus salivarius strains isolated from human milk and vaginal samples to degrade and/or conjugate parental estrogens in vitro and under aerobic conditions. The quantification of estrogens and their derivatives was carried out in cell-free supernatants by LCQQQ-MS. All the tested L. salivarius strains achieved an average degradation rate of estrone and estriol of 98% and 55%, respectively, whereas 17β-estradiol was preferentially conjugated (up to 40%). The presence of seven out of ten genes encoding enzymes relevant for estrogen metabolism was further confirmed by PCR, highlighting their genetic potential for degrading, conjugating and/or deconjugating estrogens. The tested L. salivarius strains may be considered potential probiotics affecting the fate of endogenous estrogens. Clinical trials targeting populations with estrogendependent conditions will be required to elucidate the true potential of these strains for the restoration and maintenance of a healthy host estrobolome.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal article2072-6643https://www.mdpi.com/2072-6643/16/6/861https://www.mdpi.com/journal/nutrientsopen access636.09Estrone17β-estradiolLigilactobacillus salivariusBacteria-degrading estrogensProbioticsVeterinaria3109 Ciencias Veterinarias