Interest in adolescent mental health is growing as studies highlight increased stress, anxiety, and depression in this age group. Teens are facing increased biological, social, and environmental pressure to manage stressors while their bodies and brains are still developing. According to the National Institute of Mental Health, 1 in 5 adolescents ages 12-17 have had at least one major depressive episode in the past year - an increase from 1 in 9 a decade ago.
As researchers explore new ways to treat mental health conditions in teens beyond traditional therapy and medications, one area of growing interest is the connection between the gut and the brain, known as the gut-brain axis. Related research on adults has shown a connection between the brain and gut bacteria that influences mood through inflammation and brain chemicals like serotonin. This begs the question: Could treating gut bacteria in teens be effective in treating their depression?
Cherry Leung , PhD, RN, associate professor of community health systems with the UC San Francisco School of Nursing, studies the impact of probiotics to supplement prescription medication like antidepressants on adolescents. Her research is supported by National Institutes of Health (NIH) funding.
What is the gut-brain axis, and why is it important for mental health?
The gut-brain axis refers to the communication network between the digestive system and the brain. Research shows that bacteria in the gut can send signals to the brain through multiple pathways, including hormones, the immune system, and the nervous system - particularly the vagus nerve. These signals can influence mood, stress responses, and overall well-being.
The communication is bidirectional, meaning the brain can affect the gut through the same pathways. For example, feeling nervous or stressed can alter digestion and lead to symptoms like nausea or stomach discomfort.
How can probiotics help reduce depressive symptoms?
Probiotics are "good bacteria" that can support gut health by improving microbial balance in the digestive system. Studies suggest that a healthy gut microbiome (the community of bacteria in the gut) can influence mental health in adults by reducing inflammation, regulating stress-related hormones, and affecting neurotransmitters such as serotonin.
Serotonin helps regulate mood, sleep, appetite, and digestion. It contributes to feelings of well-being and happiness, and disruptions in serotonin signaling have been linked to depression and anxiety. Many patients with depression are prescribed Selective Serotonin Reuptake Inhibitors (SSRIs), which work by increasing the availability of serotonin in the brain.
