ENDOMETRIAL MICROBIOME

The human microbiome (the total amount of bacteria inhabiting humans) has arisen clinical
interest in the last few years, since it plays important roles in health and diseases. Contrary to
long-­standing assumptions, it is now known that the endometrium of females is also often
inhabited by normal, non-­pathogenic bacteria. Recent studies show that the microbial
composition of the endometrium plays an important role in a successful pregnancy. Especially
the number of lactobacilli, also known as lactic acid bacteria, is crucial for a successful
implantation of the embryo into the uterine lining. With new molecular techniques, such as
next-­generation sequencing, a detailed analysis of the total amount of bacteria in the
endometrium can be carried out. Even bacterial strains, which cannot be detected via
traditional cultivation, can hereby be identified.
Genetic analysis
After a small biopsy from the endometrium has been obtained with a pipelle, the DNA will be
isolated and specific loci of the bacterial DNA will be amplified through polymerase-­chain
reaction (PCR). At this point a first check is done if any bacteria are present in the endometrium.
If this is the case, the bacterial DNA will be prepared for high-­troughput sequencing where
thousands of DNA fragments are simultaneously sequenced, allowing a cost-­effective
assessment of the whole microbiome. After sequencing, data of every analyzed sample will
individually be evaluated, assessed and interpreted. Thereby the following questions can be
answered:
• Is the endometrium inhabited by bacteria?
• Which kind of bacteria can be found in the endometrium?
(All bacteria with a frequency above 1% are specified.)
• What is the percentage of lactobacilli, which are critical for a healthy uterine lining?
• Are any harmful bacterial strains present, which could cause an inflammation?
Advantages of the analysis
The endometrial microbiome can have a significant contribution to a successful
pregnancy. Through the analysis of the microbiome, it can be determined whether the
bacterial composition in the endometrium is ready for the accommodation of an embryo
or if dysbiosis is present, which can complicate the embryonic implantation into the uterine
lining.
In the presence of dysbiosis or harmful bacteria, your doctor can develop an individual
treatment plan with antibiotics and/or probiotics, which can then positively change the
bacterial composition to a normal, lactobacilli-­dominant microbiome