New study reveals the relationship between hormones and gut health

Exciting results from an Israeli study have just been published in Cell Press.

The study, led by Omry Koren, collected stool samples from 35 pregnant women aged 23 – 42 and determined that pregnancy related changes to microbiota are facilitated by progesterone. The study gives researchers greater insight into the relationship between gut health and maternal hormones during the process of pregnancy.


Of particular note is that progesterone promotes the growth of Bifidobacterium during the third trimester of pregnancy. Previous studies have documented that women who have reduced amounts of Bifidobacterium during their pregnancies are linked to a higher risk of pre-term birth. However, those women with higher levels of Bifidobacterium may benefit during pregnancy such as ‘moderating weight gain, improving insulin sensitivity and glucose tolerance, and boosting the immune system.’ Additionally, higher levels of Bifidobacterium in newborns has been associated with lower disease states, as well as contributing to the newborns’ ability to digest the complex carbohydrates present in breast milk.

 As a result of their findings, the authors hypothesise that increased levels of Bifidobacterium during late pregnancy reflect an ‘evolutionary process of preparation’ for birth and breastfeeding. To read the full paper, please click here.

 Full Article Reference:
Nuriel-Ohayon, M., Neuman, H., Ziv, O., Belogolovski, A., Barsheshet, Y., Bloch, N., Uzan, A., Lahav, R., Peretz, A., Frishman, S., Hod, M., Hadar, E., Louzoun, Y., Avni, O. and Koren, O. (2019). "Progesterone Increases Bifidobacterium Relative Abundance during Late Pregnancy." Cell Reports 27(3): 730-736.e733. DOI: