Associations between psychological or biological stress indicators and gut microbiota in pregnant women – findings from a prospective longitudinal study

Abstract

The perinatal period has been linked with higher vulnerability to stress and symptoms of depression and anxiety, as well as with dynamic changes in the composition of maternal gut microbiota. While recent studies indicated significant associations between stress, depression, or anxiety, and alterations in gut microbiota in pregnant women, research in this avenue is still emerging, with existing studies often being limited by small sample sizes. We conducted a prospective longitudinal study of 171 women, collecting gut microbiota samples in each trimester of pregnancy and in the early postpartum, questionnaire data (perceived stress via the Perceived StressScale, symptoms of depression via the Edinburgh Postnatal Depression Scale, and anxiety via the 6-item State-Trait Anxiety Inventory) twice in each trimester and twice in the early postpartum period, and blood samples for cortisollevels analysis in the first and third pregnancy trimesters. The present study results contradict previous research that indicated significant associations between emotions and gut microbiota in the perinatal period. Although we cannot provide an ultimate explanation for this discrepancy, we propose it can lie in insufficient control for false positives in the differential abundance analyses in most previous studies.