The Microbiome in (Non-) Obese Pregnancy and Pregnancy Outcomes

With the increasing global prevalence of obesity, pregnancy problems related to maternal obesity are increasingly occurring. Microbial gut symbiosis plays an important role in health, with dysbiosis being associated with diseases such as obesity. Of interest are pregnancy, dietary patterns and pre- or probiotics that affect the composition of the gut microbiome. The microbiome itself can influence many physiological processes, such as immune responses (production of microbial products) and the nutrient-dependent one-carbon metabolism. It is hypothesized that gut dysbiosis, due to maternal obesity, during pregnancy can be considered an endogenous chronic stressor causing impaired immune response and carbon metabolism. Both processes result in excessive oxidative stress, detrimental to cell replication, differentiation and epigenetic programming of maternal and infant tissues. Together, these biological disturbances contribute to placental and vascular dysfunction, leading to an increased risk of preeclampsia or gestational diabetes mellitus. Vertical (during pregnancy) and horizontal (during delivery) transmission of gut dysbiosis from mother to newborn and epigenetic placental and foetal changes may ultimately lead to macrosomia and obesity in children. Therefore, the differences between the gut and vaginal microbiome, maternal and fetal immune responses and one-carbon metabolism in obese versus normal-weight pregnant women will be analysed.