Annacandida Villani1, Andrea Fontana2, Stefano Barone3, Silvia de Stefani4, Mariangela Primiterra4, Massimiliano Copetti2, Concetta Panebianco1, Cristiana Parri3, Natale Sciannamè5, Pasqua Anna Quitadamo6, Alessandra Tiezzi4, Liliana Santana4, Annamaria Maglione5, Federica D'Amato7, Francesco Perri1, Simone Palini8, Valerio Pazienza1. 1. Gastoenterology Unit, Fondazione IRCCS "Casa Sollievo della Sofferenza" Hospital, Viale Padre Pio 4, 71013 San Giovanni Rotondo, Italy. 2. Unit of Biostatistic, Fondazione IRCCS "Casa Sollievo della Sofferenza" Hospital, Viale Padre Pio 4, 71013 San Giovanni Rotondo, Italy. 3. Unità Sanitaria Locale USL Toscana Nordovest, Assisted Reproductive Center Ospedale Versilia, 55041 Lido di Camaiore, Italy. 4. PMA Unit, Clinica Nuova Ricerca, Via Settembrini 17/h, 47923 Rimini, Italy. 5. Gynecology and Obstetrics Department, IRCCS "Casa Sollievo della Sofferenza", 71013 San Giovanni Rotondo, Italy. 6. Neonatology Unit, Fondazione IRCCS "Casa Sollievo della Sofferenza", 71013 San Giovanni Rotondo, Italy. 7. PMA Unit, Villa Margherita Hospital, Viale di Villa Massimo, 48, 00161 Roma, Italy. 8. Pathophysiology of Reproduction Unit, Ospedale "Cervesi" di Cattolica-AUSL Romagna, Via Ludwig Van Beethoven, 1, 47841 Cattolica, Italy.
Abstract
BACKGROUND AND AIMS: Failure of the embryo to implant causes about three-fourths of lost pregnancies. Female genital tract microbiota has been associated to Assisted Reproductive Technologies (ART) outcomes. The objective of this study was to analyze the microbiota of human cervical swab and to correlate these findings with the ART outcomes. MATERIALS AND METHODS: In this study, 88 cervical swabs were collected from women undergoing ART cycles, with various causes of infertility, at the beginning of the ART protocols. After microbial DNA extraction, V3-V4 variable regions of the 16S rRNA gene were amplified and sequenced on the Illumina MiSeq platform. PEnalized LOgistic Regression Analysis (PELORA) was performed to identify clusters of bacterial populations with differential abundances between patients with unfavorable and favorable pregnancy outcome groups, respectively. RESULTS: We identified a core of microorganisms at lower taxonomic levels that were predictive of women's pregnancy outcomes. Statistically significant differences were identified at species levels with Lactobacillus salivarius, Lactobacillus rhamnosus among others. Moreover the abundance of Lactobacillus crispatus and iners, respectively increased and decreased in favorable group as compared to unfavorable group, resulted within the core of microorganisms associated to positive ART outcome. Although the predominance of lactobacilli is generally considered to be advantageous for ART outcome, we found that also the presence of Bifidobacterium (together with the other lactobacilli) was more abundant in the favorable group. DISCUSSION: Cervix is colonized by microorganisms which can play a role in ART outcomes as seen by an overall decrease in embryo attachment rates and pregnancy rates in both fertile and infertile women. If confirmed in a larger cohort, the abundance of these bacteria can be useful not only as a marker of unfavorable pregnancy outcome but also they may open the way to new interventional strategies based on genital tract microbiota manipulation in order to increase the pregnancy rates in woman undergoing assisted reproductive technologies.
BACKGROUND AND AIMS: Failure of the embryo to implant causes about three-fourths of lost pregnancies. Female genital tract microbiota has been associated to Assisted Reproductive Technologies (ART) outcomes. The objective of this study was to analyze the microbiota of human cervical swab and to correlate these findings with the ART outcomes. MATERIALS AND METHODS: In this study, 88 cervical swabs were collected from women undergoing ART cycles, with various causes of infertility, at the beginning of the ART protocols. After microbial DNA extraction, V3-V4 variable regions of the 16S rRNA gene were amplified and sequenced on the Illumina MiSeq platform. PEnalized LOgistic Regression Analysis (PELORA) was performed to identify clusters of bacterial populations with differential abundances between patients with unfavorable and favorable pregnancy outcome groups, respectively. RESULTS: We identified a core of microorganisms at lower taxonomic levels that were predictive of women's pregnancy outcomes. Statistically significant differences were identified at species levels with Lactobacillus salivarius, Lactobacillus rhamnosus among others. Moreover the abundance of Lactobacillus crispatus and iners, respectively increased and decreased in favorable group as compared to unfavorable group, resulted within the core of microorganisms associated to positive ART outcome. Although the predominance of lactobacilli is generally considered to be advantageous for ART outcome, we found that also the presence of Bifidobacterium (together with the other lactobacilli) was more abundant in the favorable group. DISCUSSION: Cervix is colonized by microorganisms which can play a role in ART outcomes as seen by an overall decrease in embryo attachment rates and pregnancy rates in both fertile and infertile women. If confirmed in a larger cohort, the abundance of these bacteria can be useful not only as a marker of unfavorable pregnancy outcome but also they may open the way to new interventional strategies based on genital tract microbiota manipulation in order to increase the pregnancy rates in woman undergoing assisted reproductive technologies.
Authors: Inmaculada Moreno; Francisco M Codoñer; Felipe Vilella; Diana Valbuena; Juan F Martinez-Blanch; Jorge Jimenez-Almazán; Roberto Alonso; Pilar Alamá; Jose Remohí; Antonio Pellicer; Daniel Ramon; Carlos Simon Journal: Am J Obstet Gynecol Date: 2016-10-04 Impact factor: 8.661
Authors: Anna Klindworth; Elmar Pruesse; Timmy Schweer; Jörg Peplies; Christian Quast; Matthias Horn; Frank Oliver Glöckner Journal: Nucleic Acids Res Date: 2012-08-28 Impact factor: 16.971