For those with irritable bowel syndrome(IBS) who wonder if stress aggravates their intestinal disorder, a new study has shown that it’s not all in their head.

Researchers at the University of Michigan Health System revealed that while stress does not cause IBS, it does alter brain-gut interactions and induces the intestinal inflammation that often leads to severe or chronic belly pain, loss of appetite and diarrhoea.

Stress has a way of suppressing an important component called an inflammasome which is needed to maintain normal gut microbiota, but probiotics reversed the effect in animal models, according to the findings.

“The effect of stress could be protected with probiotics which reversed the inhibition of the inflammasome,” senior study author and gastroenterologist John Y Kao, associate professor of internal medicine at the University of Michigan said.

“This study reveals an important mechanism for explaining why treating IBS patients with probiotics makes sense,” he said.

Probiotics are live bacteria that help grow the gut-dwelling “good” bacteria that keep pathogens in check, aid digestion and nutrient absorption and contribute to immune function.

U-M researchers including Chung Owyang, chief of the U-M Division of Gastroenterology, Gary Huffnagle, professor of pulmonary and critical care, and infectious disease expert Vincent Young, were able to identify the way stress significantly altered the composition of gut bacteria and the role of probiotics.

Maintaining healthy microbiota requires action by nucleotide-binding oligomerization domain protein-like receptors, pyrin-domain containing (NLRP)-6 inflammasomes. But when stressed, mice produced corticotropin-releasing hormone (CRH) that prevented inflammasomes from doing their job.