A study identifies more than 5.300 different microorganisms, including viruses, bacteria and fungi, within the uterus of healthy women
Scientists from the University of Granada, the CSIC and the Virgen de las Nieves Hospital in Granada describe and analyze the functional microbiota that inhabits the uterus of healthy women by analyzing RNA sequences.
A study carried out by scientists from the ibs.GRANADA, the University of Granada (UGR), the CSIC and the Virgen de las Nieves Hospital in Granada has identified more than 5.300 different microorganisms (viruses, bacteria and fungi, among others) inside the uterus of healthy women.
His work, which publishes Human Reproduction, one of the world's most prestigious journals in the field of human reproduction, has described and analyzed the potentially functional microbiota that inhabits the uterus of healthy women by analyzing RNA sequences.
As Alberto Sola-Leyva, a trainee researcher in the human reproduction group at ibs.GRANADA and predoctoral researcher at the University of Granada and first author of the article, explains, “few tissues in our body, if any, are totally sterile. Most have their own microbiota, that is, a community of microorganisms (bacteria, viruses, fungi, among others) that inhabit a defined site.
Most of the bacterial communities present in humans coexist without causing harm, but rather benefit. However, an imbalance in this relationship can lead to illness. In the context of human reproduction / fertility, it is well known that the vagina possesses a highly active microbiota. But it is that, until very recently, it was assumed that the human uterus was a completely sterile environment.
Recently, the group from the University of Granada, in collaboration with bioinformaticians from the “López-Neyra” Institute of Parasitology and Biomedicine (CSIC) and doctors from the Reproduction Unit of the Virgen de las Nieves Hospital, has published this interdisciplinary work, in which they describe the composition of the active microorganisms that inhabit the uterus of healthy women, and suggest the metabolic routes where they could participate.
In addition, researchers have determined that the composition of these microorganisms fluctuates throughout the menstrual cycle. This innovative study has been led by Signe Altmäe, and has the collaboration of Eduardo Andrés-León.
Until now it was known that the uterus contains sequences of bacterial DNA, but it is unknown whether these pieces of microbial genetic material are degradation debris or are functionally active microbes.
The endometrial microbiota in “action”
"Thanks to this new methodological approach, we have been able to analyze the live microbiota of the endometrium of healthy women, which in this case is made up of more than 5300 microorganisms and differs from the microbial composition of the vagina," says Altmäe.
Among the activities carried out by microorganisms inside the uterus, the results of the study show that, during the menstrual phase in which the embryo implants, they are involved in the biosynthesis of prostanoids (derived from essential fatty acids) and the metabolism of L- tryptophan, both crucial for establishing pregnancy.
"Advances in understanding the uterine microbiome may lead to the identification of minimally invasive microbial biomarkers and an improvement in gynecological treatments with currently unknown clinical and therapeutic implications at the uterine level," the authors conclude.
Bibliographic reference:
Alberto Sola-Leyva, Eduardo Andrés-León, Nerea M Molina, Laura Carmen Terron-Camero, Julio Plaza-Díaz, María José Sáez-Lara, María Carmen Gonzalvo, Rocío Sánchez, Susana Ruíz, Luís Martínez, Signe Altmäe, Mapping the entire functionally active endometrial microbiota, Human Reproduction, 2021; deaa372, https://doi.org/10.1093/