Nov. 8, 2022 – Laboratory mice exposed to repeated emotional stress showed symptoms similar to those of irritable bowel syndrome, new research shows.

The results add to a growing body of evidence linking the brain, diet, and gut. The study was published in the journal Frontiers in Neuroscience.

The researchers put the mice under physical stress or emotional stress. The animals either endured physical aggression or witnessed the aggression for 10 minutes per day for 10 consecutive days, according to a news release from Tokyo University of Science, where the research was done.

There were no significant effects in the mice that were under physical stress, compared to a control group. But symptoms similar to IBS were seen in the emotionally stressed mice, and the symptoms persisted for 1 month. 

“From the aspect of the gut-brain axis, we suspect that the insular cortex plays an important role in determining the phenotype of emotionally-stressed mice,” author and professor Akiyoshi Saitoh, PhD, said in the news release. 

The insular cortex is a part of the upper central nervous system controlling digestive functions and is involved in the process of coping with psychological stress, the news release explained.

The Mayo Clinic says IBS is a “common disorder” affecting the gastrointestinal tract, with symptoms such as cramping, bally pain, bloating, gas, diarrhea, and constipation. 

“Some people can control their symptoms by managing diet, lifestyle and stress,” according to the Mayo Clinic. “More severe symptoms can be treated with medication and counseling.”

The American College of Gastroenterology estimates IBS affects between 10% and 15% of American adults, but only 5% to 7% are diagnosed. Twice as many women have IBS, compared to men.