A team of scientists from the University of Granada, the CSIC and the Virgen de las Nieves Hospital in Granada has identified more than 5,300 different microorganisms, including viruses, bacteria and fungi, within the uterus of healthy women. The results reveal that the microbiota of this organ is very rich and varied, different from the vaginal microbiota and, in addition, it changes depending on the moment of the menstrual cycle.
“You are a walking sack of bacteria,” biologist Lynn Margulis once told an interviewer. The resounding statement of the scientist reminds us that, indeed, bacteria and other microorganisms are present everywhere and inhabit all environments that can be imagined, including our tissues. Most of these microscopic communities coexist with us without causing harm and even being beneficial, while imbalances in these flora can cause problems. The intestinal and vaginal microbiota are some of those communities that are well studied and stand out for being very active but, in the case of the uterus, it had always been thought that it was a rather sterile tissue.
This new work, published in the journal Human Reproduction , has described and analyzed the potentially functional microbiota that inhabits the uterus of healthy women by analyzing RNA sequences. 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.
Function in pregnancy
This work has also determined that the composition of viruses, fungi and bacteria in the uterus changes throughout the menstrual cycle and may play a role in the establishment of pregnancy.
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 the understanding of the uterine microbiome may lead to the identification of minimally invasive microbial biomarkers and an improvement in gynecological treatments with clinical and therapeutic implications at the uterine level that are currently unknown”, the authors conclude.
