Microbes in Saliva Link to Pregnancy Stress and Mental Health

A groundbreaking study published in the open access journal BMJ Mental Health has revealed a significant connection between the oral microbiome of pregnant women and their mental health, providing new insights into the role of microorganisms in maternal well-being.

Conducted by researchers at Michigan State University, the study enrolled 224 pregnant women as part of the Michigan Prenatal Stress Study. The participants were assessed for recent stress and mental health symptoms during their second trimester and provided saliva samples during the week of assessments. The results showed a striking difference in the oral microbiome based on whether women had reported life stress, anxiety, depression, or post-traumatic stress disorder (PTSD) symptoms.

According to lead researcher Joseph Lonstein, Professor in MSU's Department of Psychology, "Positive mental health is crucial for mothers' well-being and their ability to sensitively care for infants. We hope our study will stimulate future research on how microbes in and on our bodies are associated with mental health in mothers and even people who are not mothers."

The study found that women experiencing high anxiety or depression symptoms had oral microbiomes with a "high alpha diversity," indicating an abundance of different microbe species present at relatively even levels. In contrast, those with high PTSD symptoms showed a "high beta diversity," signifying drastically differing types of microbe species in their saliva compared to those with low PTSD symptoms.

The researchers also discovered specific stress and mental health traits linked to distinct microbe populations in the saliva. Importantly, the study's findings highlight the oral microbiome as a potential target for interventions aimed at improving poor psychological well-being during pregnancy.

"Successful targeting of the gut microbiome with probiotic treatment to improve maternal mental health could be extended to target oral cavity microbes through dietary changes and recommending oral health improvements and probiotic treatments that might benefit mothers struggling with high life stress and poor mental health," cautioned the study team.