Why fasting doesn’t trigger gut inflammation

New York: A genetic switch that is turned on in the brain during fasting helps halt the spread of intestinal bacteria into the bloodstream, says a new study.

The study shows a molecular pathway by which the brain communicates with the gastrointestinal (GI) tract to prevent unnecessary activation of the immune system during fasting by strengthening the barrier against gut microbes.

The discovery of this brain-gut signal in fruit flies, which has many parallels to humans, could eventually inform the treatment of inflammatory bowel diseases in people, said the study published in the journal Proceedings of the National Academy of Sciences.

In addition to its role in promoting the absorption of nutrients from food, the GI tract is host to a panoply of bacteria. These microbes actually help in the digestive process by producing chemicals that break down complex fats and carbohydrates.

“Fasting has a positive value that spills over not just into the metabolic system, but also inflammation and brain function,” said the study’s lead investigator Marc Montminy, professor at Salk Institute for Biological Studies in La Jolla, California, US.

“Understanding how the gut maintains this barrier, and creating drugs to enhance that barrier, may have important benefits for people with inflammatory bowel disease,” Montminy noted.

The new study is part of an ongoing research to pin down the mechanisms that a genetic switch in the brain called Crtc uses to control energy balance.