“When we see adult or pediatric patients with disorders of gut-brain interaction, we shouldn’t only be asking about recent stressors, but lifelong stressors as well,” says study coauthor Kara Margolis, MD, director of the NYU Pain Research Center. “Stressors during development make a difference in long-term symptoms.”
Here’s what doctors who treat patients with digestive disorders want you to know.
The Link Between Early Stress and Later Gut Issues
For the study, researchers compared mouse models with two large studies of children.
For the mouse study, researchers separated young mice from their mothers for several hours a day to mimic early life stress. Several months later — the mouse equivalent of young adulthood — the rodents were more likely to show anxiety-like behaviors, along with gut pain and motility (movement) issues like constipation or diarrhea.
To see how this may play out in humans, researchers looked at health data from more than 40,000 Danish infants, half of whom were born to mothers with undiagnosed depression during or after pregnancy. They discovered that infants born to undiagnosed moms who didn’t take antidepressants had a higher risk of a range of digestive disorders, including IBS, chronic constipation without any obvious cause, and colic.
In the second human study, the researchers analyzed data from nearly 12,000 American children who took part in the Adolescent Brain Cognitive Development study. The researchers focused on whether children had been through negative childhood experiences like abuse or neglect, or if their parents had mental health problems. The researchers then looked at which children developed digestive issues when they were 9 and 10. Those who had early childhood stress had a greater risk of gastrointestinal symptoms.
Dr. Margolis says the findings echo what she sees with her patients. “In the office, it became highly apparent to me that many of the kids I was seeing not only had acute stress but had a long history of challenging circumstances with gastrointestinal problems and anxiety and/or depression,” she says.
Your Gut Is Like a ‘Second Brain’
The gut-brain axis is a bidirectional network where the brain communicates with the gut and vice-versa. “The gut and the brain are in constant conversation,” says Trisha Pasricha, MD, MPH, an assistant professor of medicine at Harvard Medical School and director of the Institute for Gut-Brain Research at Beth Israel Deaconess Medical Center, both in Boston. “They communicate through nerves, hormones, and immune signals.”
Childhood is an especially vulnerable time because the nervous system is developing, Dr. Pasricha says. “The sensory neurons become excited much more easily compared to older children and adults,” she explains. “Because of this, repeated experiences of pain or stress early in life can permanently lower the threshold at which the body sounds the alarm.”
Exposure to more stressors at a younger age can create a “negative feedback” on the gut, says Rishi Naik, MD, an assistant professor of medicine in the division of gastroenterology, hepatology, and nutrition at Vanderbilt University Medical Center in Nashville, Tennessee. “Even when the stressor is gone, the impact can be durable, leading to gut symptoms,” he says.
Dr. Naik says that research and findings on the gut-brain axis are evolving. “This bidirectional flow allows stressors, fear, adversity, or trauma to feed back into your ‘second brain’ [the gut], which can then manifest as pain, cramping — even before an important event, the ‘butterflies in your stomach,’” he says.
“The feedback loop goes both ways, where changes in your GI tract including constipation, diarrhea, and inflammation can lead you to feel tired, lethargic, fatigued, or irritable,” Naik explains.
Pasricha says the latest findings imply that this two-way feedback may continue for longer than scientists previously realized. “It suggests that the gut-brain connection isn’t just something that responds to what we’re feeling in a particular moment,” she says. “The way these systems develop during childhood may also influence how the digestive system functions decades later.”
Other Possible Causes of Digestive Disorders
Digestive issues aren’t universally caused by early stress, says Rudolph Bedford, MD, a gastroenterologist at Providence Saint John’s Health Center in Santa Monica, California.
“Much of what we see related to IBS these days can be food-related, hormone-related, and due to disruption of the bacteria of the gut,” Bedford says. “There are many things we confront as gastroenterologists that can disrupt the GI system.”
Pasricha also wants to assure parents: “Having a child with digestive issues does not mean a parent did something wrong,” she says. “The gut-brain axis is shaped by many factors — genetics, the microbiome, infections, and yes, sometimes stress. But stress is just one piece of a complex puzzle. Parents of children with IBS, colic, or other GI disorders are often doing everything right and still watch their child struggle. This research should inspire more targeted treatments, not more guilt.”
How the Findings Can Help People With Digestive Disorders
While there have been large innovations in diagnosing digestive cancers, Naik says the same innovations are needed for people with chronic gastrointestinal issues with no known cause.
“Understanding the impact of early trauma can help with therapeutic management,” he says. “Early identification of these stressors should prompt early recognition and timely intervention to allow remodeling and prevent long-term impact of the gastrointestinal tract.”
Margolis and her research team are still investigating new ways to treat people with digestive disorders. But she stresses that it’s important for people with digestive issues to realize that there are many potential treatments out there to help, including lifestyle modifications.
“I encourage all my patients to eat a whole food, high-fiber diet, get consistent sleep, exercise, and walk in nature,” she says. “All of these things can work to help these conditions.”