Gut bacteria is a hot topic in science today — and for good reason. Our intestines harbor more than 100 trillion bacteria and other gut microbial cells that influence our metabolism, nutrition, and general health and disease. Investigating a common bacterium in the intestine, Technion researchers have made a discovery that could lead to a better understanding and treatment of inflammatory bowel diseases (IBD) such as colitis and Crohn’s disease.

In a process of co-evolution with humans over millions of years, gut bacteria became essential to the proper functioning of our immune system and health, and acquired the ability to adapt to changes in their environment. The mechanism that enables such adaptation is their ability to undergo rapid genomic changes, due to a trait known as plasticity.

In analyses of more than 2,000 healthy and sick individuals and preclinical research in model mice, a team of scientists identified patterns of DNA reversible inversions that could switch ON or OFF the production of molecules responsible for inducing beneficial immune cells that suppress excessive inflammation and maintain gut homeostasis. The researchers, led by Professor Naama Geva-Zatorsky at the Rappaport Faculty of Medicine, also discovered the culprit: bacteriophages — viruses that infect bacteria, turning the switch OFF.

“This research offers critical insight into the intricate interactions between gut bacteria and the immune system in inflammatory bowel disease,” said Prof. Geva-Zatorsky. “The same genomic flexibility that was developed through evolution provides the bacteria with functional plasticity, thereby helping them to adapt to intestinal disease. It opens doors for targeted interventions aimed at restoring the balance of gut microbiota in IBD patients.”

The research was supported by the European Research Council, the Technion President’s Fund, the Ruth and Bruce Rappaport Cancer Research Center, the Dan and Betty Kahn Foundation, and other noteworthy institutions.