When gestational diabetes harms the placental microbiota

Actu GP Quand le diabète gestationnel nuit au microbiote du placenta

A pregnancy complicated by an excessively high blood sugar level is the fate of a growing number of expecting mothers… and their unborn babies. A study exposed the harmful consequences of this condition on the bacteria of the placenta, where the first flora of our life is thought to develop.


The type 2 diabetes epidemic which is raging around the entire world with no signs of slowing down, does not spare pregnant women: one baby in seven is born to a mother whose blood sugar level is above normal during pregnancy, which is called gestational diabetes. Already dangerous for the mother, exposed de facto to cardiovascular risks, this diabetes might also leave its mark on the placenta, a vital organ responsible for the intake of nutrients and oxygen, elimination of waste, carbon dioxide and certain toxins, viruses and bacteria… as well as the bacteria of the maternal flora (intestinal, oral, vaginal and urinary), as certain researchers are starting to suggest.

A different placental microbiota

A Chinese team collected placentas and umbilical cord blood from babies at birth in a Beijing hospital. Half of the mothers had gestational diabetes; the others had experienced a normal pregnancy, and all had undergone a cesarean section–a criterion which allowed the mode of delivery to be ruled out as a factor influencing the results. Marked differences between the placental microbiotas of these two groups emerged, with a lower level of “good” bacteria in the diabetic mothers.

A cake as legacy

The researchers then linked their results to the presence in cord blood of three hormones associated with sugar metabolism and fetal development: insulin, a growth factor and leptin (one of the satiety hormones). Associations between certain bacteria and each of these three hormones were established, a sign that the placental bacteria might also take part in the great metabolic adventure of the fetus. Research in this field is still in its early stages and future studies must carry out further groundwork, especially with regard to the inflammatory and immune mechanisms likely to be at work. Chance or coincidence, “placenta” comes from the Latin word meaning “cake”. Some people could see a sign here...



Zheng J, Xiao X, Zhang Q, Mao L, Yu M, Xu J, Wang T. The Placental Microbiota is Altered among Subjects with Gestational Diabetes Mellitus: A Pilot Study. Front Physiol. 2017 Sep 6;8:675. doi: 10.3389/fphys.2017.00675.eCollection 2017