Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Baskent University, Ankara, TurkeyTurkey
Division of Perinatology, Department of Obstetrics and Gynecology, Baskent University, Ankara, Turkey In the recent years, our knowledge about human reproductive system has increased with the development of assisted reproductive technologies; however, embryo implantation rate is still around 25-30%.
Also available as PDF (figures and tables appear in the PDF).
In the recent years, our knowledge about human reproductive system has increased with the development of assisted reproductive technologies; however, embryo implantation rate is still around 25-30%.1 Embryo implantation depends on the quality of the embryo, endometrial receptivity and the embryo/endometrial interface.
Editorial A Novel Contributor to Endometrial * *Corresponding author Receptivity: Endometrial Microbiota Sertaç Esin, MD Associate Professor Division of Perinatology 1 2* Department of Obstetrics and Gynecology Yusuf Aytaç Tohma, MD1; Sertaç Esin, MD2* Baskent University Şehit Temel Kuğuoğlu Cad. No:34 Bahçelievler, Ankara, Turkey 1 Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and E-mail: sertacesin@gmail.com Gynecology, Baskent University, Ankara, Turkey 2Division of Perinatology, Department of Obstetrics and Gynecology, Baskent University, Volume 4 : Issue 1 Ankara, Turkey Article Ref. #: 1000GOROJ4e006 Article History In the recent years, our knowledge about human reproductive system has increased th with the development of assisted reproductive technologies; however, embryo implantation Received: May 9 , 2017 th Accepted: May 10th, 2017 rate is still around 25-30%.1 Embryo implantation depends on the quality of the embryo, endo- th Published: May 10th, 2017 metrial receptivity and the embryo/endometrial interface.2 The onset of implantation is a suc- cessful concurrence of 2 different processes; embryo development and endometrial differentia- tion. Therefore, synchronization between development of a good quality embryo and receptive Citation 2,3 endometrium is paramount for the success of embryo implantation and ongoing pregnancy.
Tohma YA, Esin S. A novel contribu- tor to endometrial receptivity: En- The association between embryo and receptive endometrium during implantation is not fully dometrial microbiota. Gynecol Ob- understood yet, because in vivo studies about implantation are scarce due to ethical and techni- stet Res Open J. 2017; 4(1): e1-e3.
4,5 cal problems. So our knowledge about implantation is mostly derived from animal studies. doi: 10.17140/GOROJ-4-e006 Microbiota which was fully defined in 2001 is regarded as the second genome, and its 6-9 importance in reproductive system has newly understood.6-9 Microbiota is a source of genetic diversity and is important for normal immune system, metabolism and behavior of the dis- ease.10 Microbiota inhabits different systems of the body and there is a synergistic interaction between microbiota and its host.10 Due to these known synergistic effects, microbiota trans- plantation has been used as a treatment for recurrent Clostridium difficile infection which may be difficult to manage with conventional antibiotic therapies. Fecal microbiota transplantation 11,12 from a healthy person to the patient restores the gut microbiota to a healthy state.
Endometrial receptivity is regulated by synchronization of different cell types and several factors such as luminal and glandular epithelium, cytokines, growth factors, proteas- 2,3 es, glucose, hormones and enzymes.2,3 Recent research has also revealed the importance of 13,14 endometrial microbiota and its possible impact in endometrial receptivity. Until recently, endometrium was classically considered a sterile cavity and when the reproductive system microbiota was considered, vaginal microbiota came to mind.15 However, new techniques and technologies such as microarrays, DNA fingerprinting, and targeted or whole genome sequenc- ing have empowered the field of metagenomics and have begun to change the way we think of reproductive system microbiota.16 With help of these innovations, identification of microorgan- isms in uterine cavity of asymptomatic patients undergoing hysterectomy for benign indica- tions confirmed that the uterine cavity is not sterile and endometrium has an own microbiota such as Gardnerella vaginalis, Lactobacillus spp., Enterobacter spp. and Mycoplasma hominis and is independent from hormonal regulation.14 In the future, endometrial microbiota transplan- tation may be used for recurrent implantation failure patients.
Copyright Recent studies reported that non lactobacillus microbiota domination in endometrial ©2017 Esin S. This is an open ac- cavities is strongly correlated with failure of implantation as compared to lactobacillus domi- cess article distributed under the 14,17 nated endometrial microbiota. Because balance in inflammatory factors is important for Creative Commons Attribution 4.0 regulation of the adhesion of the blastocyst to the epithelial endometrial wall, non-lactobacillus International License (CC BY 4.0), which permits unrestricted use, dominated microbiota may cause inflammation in the uterine cavity and impair endometrial distribution, and reproduction in receptivity.14 We need new studies focusing on the interaction between endometrial microbiota any medium, provided the original and receptivity.
As a result, a human endometrial microbiota exists and is independent of hormonal regulation. Non-Lactobacillus domi- nant endometrial microbiota impairs endometrial receptivity and may result in implantation failure and pregnancy loss but lactoba- cillus dominancy is a supporter of healthy reproductive system. Now, we have to know that endometrial receptivity is not only under control of the morphological and molecular factors but endometrial microbiata has substantial functions for endometrial integrity and successful implantation. It is time to consider microorganisms not only as enemies but also as allies in reproductive medicine.
CONFLICTS OF INTEREST None of the authors have a financial relationship with a commercial entity that has an interest in the subject of this manuscript.