RT Journal Article T1 Investigating the Metabolism of Estrogens in Ligilactobacillus salivarius Strains Isolated from Human Milk and Vaginal Microbiota A1 Aragón, Alberto A1 Jurado Escobar, Rubén A1 Jara Pérez, Josué A1 Rodríguez Gómez, Juan Miguel A1 Orgaz Martín, Belén AB 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. PB MDPI YR 2024 FD 2024-03-16 LK https://hdl.handle.net/20.500.14352/103155 UL https://hdl.handle.net/20.500.14352/103155 LA eng NO : 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/nu16060861 NO This article belongs to the Special Issue Probiotics and Homeostasis: How Probiotics Interact with Digestive Systems to Participate in Human HealthAuthor 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. NO Ministerio de Ciencia, Innovación y Universidades NO Ministerio de Educación DS Docta Complutense RD 6 oct 2024