Microbiome and reproductive health research

Recent medical research has identified several links between microbiomes and reproductive health. A study involving couples in Denmark and Sweden, published in The Lancet Obstetrics, Gynaecology & Women's Health, found that bacterial imbalance, or dysbiosis, in male semen is associated with lower live-birth rates and increased pregnancy loss risk during IVF treatments. Specifically, among IVF couples, 57% of those with semen dysbiosis had a baby compared with 85% without the imbalance, and miscarriage risk was approximately 26 percentage points higher when the male partner had the imbalance.

Parallel research has focused on the female endometrial microbiome. Studies, including investigations by scientists at the University of Beijing published in Cell Host & Microbe, indicate that a decline in the bacterium Lactobacillus gasseri is associated with advancing reproductive age. Experimental data involving human cells and mice suggests that supplementing this bacterium or its derivatives may improve uterine conditions and embryo implantation, potentially offering a new treatment to boost fertility in women over 35.

Additionally, research published in Diabetologia has identified a correlation between endometriosis and an increased risk of type 2 diabetes. The ARCHES study, which analyzed health records from approximately three million women in the Utah Population Database, found that women diagnosed with endometriosis face a 46% higher risk of developing type 2 diabetes. The association varies by subtype: women with superficial peritoneal endometriosis showed a 67% increased risk, while those with ovarian endometriosis showed a 61% increased risk. The strongest associations were observed in extrapelvic endometriosis. Researchers emphasized that the study shows an association rather than a direct cause-and-effect relationship, highlighting a need for further research into biological mechanisms and early metabolic screening, particularly as increased risks were observed even in women without obesity.