The role that bacteria in the gut play in the development of anxiety symptoms as early as infancy and early childhood is the focus of a first-of-its-kind study funded by a $3.6 million grant from the National Institute of Mental Health.
Associate Professor Roger Mills-Koonce, who has conducted extensive research into the interplay of biology and psychological development in children, is a co-principal investigator on the project.
The five-year project will study 200 children from infancy to 4.5 years old to learn how gut bacteria and brain development interact with each other to possibly make some people more susceptible to anxiety and depression later in life.
The project is led by Cathi Propper at the Frank Porter Graham Child Development Institute and Rebecca Knickmeyer at Michigan State University and involves a team of researchers from multiple departments and universities, including the School of Education, FPG and the School of Medicine at UNC-Chapel Hill, Michigan State University, The University of Wisconsin, Boston University, and RTI International.
The project builds on previous work by this team and others that has identified biological and psychological risk factors for the development of anxiety in early childhood. The new study will examine the interplay of home environments, brain development, and the amount and types of bacteria found in children’s digestive systems as factors affecting early risk for psychopathology.
Researchers will be seeking to discover whether a greater diversity of gut bacteria can predict lower levels of anxiety symptoms in children and will be the first to explore possible two-way relationships between gut bacteria and anxiety symptoms over time.
Identifying risk factors for psychological disorders
Researchers have found that levels and diversity of gut bacteria appear to have an effect on brain development and behavior in lab animals, but few studies have examined this phenomenon in humans.
Additionally, earlier work by this team has established that the patterns of bacteria in the digestive system — the “gut microbiome” — can significantly predict fear behavior in 1-year-old children, considered to be a predictor of psychological disorders later in life. The long-term goal of the new study is to determine how the gut microbiome impacts brain development and later risk for psychological disorders so that researchers can better understand ways to prevent the onset of psychiatric illness or to reduce its severity.
The project will study a group of children living in poverty that the team has followed since infancy in a National Institute of Child Health and Human Development-funded project called the Brain and Early Experience Study. That study has examined associations between poverty, early experiences, brain development and emerging executive functioning during the first three years of life.
In the new study, assessments will be conducted during lab visits at 15, 36, and 54 months of age and home visits at six and 24 months of age. The lab assessments will include magnetic resonance imaging brain scans to measure the growth of particular parts of the brain that have been shown to be related to development of anxiety-related disorders. Lab visits will also include collection of hair samples to measure levels of cortisol, considered to be a marker chronic stress, and collection of fecal samples to measure gut bacteria. The home visits, led by Mills-Koonce, will assess levels of family- and home environment-based stress.
The study is designed so that researchers can measure the interplay between all the relationships being examined, such as how the gut microbiome appears to affect brain development, how brain development appears to affect the gut microbiome, and how home-based stress interacts with those relationships.
Researchers will seek to identify biomarkers and behavioral indicators that can predict early trajectories of psychological disorders, providing insights that can lead to effective interventions to support mental health and treatments aimed at early prevention of anxiety disorders.
Mills-Koonce, a widely published researcher in the field of developmental science, joined the School of Education in 2018 as an associate professor in Human Development and Family Studies. He previously was on the faculty at the University of North Carolina at Greensboro, and before that was a research scientist at the Center for Developmental Science at UNC-Chapel Hill.
His work has included collaborations with colleagues in psychology, education, medicine, and exercise and sports science, including work at FPG and the Center for Developmental Science at UNC-Chapel Hill. He has served as an Investigator and co-director of the UNC-Chapel Hill-based Family Life Project, a longitudinal study of children and families living in rural poverty in the United States.
Mills-Koonce has extensive experience in the psychobiological study of relationships between parents and children as well as the role of parents in supporting adaptive and maladaptive behaviors in young children.