Prenatal Depression Does Not Alter Infant Oral Microbiome at Birth

The assembly of the infant microbiome during delivery represents a critical window for establishing the microbiota-gut-brain axis, a bidirectional communication system that regulates immune, metabolic, and neurodevelopmental homeostasis [1, 2]. Disruptions in this early microbial colonization have been linked to long-term risks for pediatric obesity, allergic diseases, and neurodevelopmental disorders [3, 4, 5]. While prenatal maternal stress is known to influence fetal outcomes through neuroendocrine and inflammatory pathways, emerging research has focused on whether maternal psychological distress also alters the vertical transmission of beneficial bacteria [6, 7]. Given that up to one-fifth of pregnant women experience depressive symptoms, understanding the stability of this microbial transfer is essential for clinical risk assessment and prenatal counseling [8]. A new study now offers clinical evidence regarding how maternal affective symptoms influence the oral microbial exposure of infants at the moment of birth.