New study proves for the first time that intestinal bacteria thrive in pregnant women

Researchers at Bar-Ilan University discovered that these bacteria "detected" pregnancy and "understood" the need to move on to the next generation to help babies break down sugar in breast milk .

Gestation accompanies alterations of the microbiome – bacteria that live in and on our bodies and weigh more than four pounds of our body weight and are important for health and the fight against diseases. Previous research on changes in the microbiome has shown that during pregnancy it is partially responsible for weight gain and essential inflammatory response. However, the mechanisms behind these changes are unknown.

A new study conducted by Dr. Omry Koren, of the Azrieli School of Medicine, in collaboration with Prof. Yoram Louzon, Department of Mathematics of the University of Bar-Ilan, and researchers from the hospital Beilinson, revealed that progesterone regulates the microbial composition of bacteria during pregnancy in a way that can help the baby to grow. The study was published today (16 April 2019) in Cell reports.

The researchers studied the changes in bacteria during pregnancy and found a dramatic change in the composition of bacteria towards the end of pregnancy, including an increase in the relative abundance of bacteria. Bifidobacterium. These bacteria are essential for infants because they metabolize healthy sugars in breast milk that are important for the growth of babies. They also contain probiotic abilities. Previous research has shown that the lack of Bifidobacterium during pregnancy is correlated with premature delivery.

The researchers, led by Koren, found that pregnant women had an increase in progesterone levels accompanied by an increased inflammatory response. They also recorded an increase in other bacteria, but Bifidobacterium was the only bacterium identical to pregnancy in mice. When they mimicked pregnancy in mice (with the help of progesterone), they again found that Bifidobacterium increased, leading them to conclude that Bifidobacterium in a way, it detects progesterone and reacts to it. When the researchers administered progesterone in vitro, they again found that Bifidobacterium has grown rapidly. This led them to conclude that Bifidobacterium detects and responds to progesterone

Our results describe a model in which progesterone promotes the growth of Bifidobacterium in late pregnancy. The results provide new information for understanding the relationship between hormones and intestinal bacteria during pregnancy, but also for other conditions in which hormones are involved, such as progesterone supplementation as a component of fertility treatments or treatment in postmenopausal women, "said Dr. Koren.

Koren and her team are now trying to determine how these bacteria react, what genes are activated, what other hormones in pregnancy do and what their effects are.