Gut inflammation and other conditions that involve the immune system are more common among people with irregular sleep patterns, including those who work night shifts. Now, new research in mice has uncovered a previously unknown mechanism that could help to explain the connection.
New research finds a body clock mechanism that may explain the link between sleep patterns and gut health.
The mechanism concerns group 3 innate lymphoid cells (ILC3s). These immune cells have a strong role in controlling metabolism, inflammation, and other biological processes.
In a recent Nature paper, the scientists explain how they used mice to better understand the role of ILC3s in the gut.
“These cells,” says senior study author Henrique Veiga-Fernandes, Ph.D., “fulfill important functions in the gut — they fight infection, control the integrity of the gut epithelium, and instruct lipid absorption.”
Veiga-Fernandes works at the Champalimaud Centre for the Unknown, in Lisbon, Portugal. He leads a group that investigates communication at the cellular level between the nervous system and the immune system.
“Sleep deprivation or altered sleep habits can have dramatic health consequences, resulting in a range of diseases that frequently have an immune component, such as bowel inflammatory conditions,” Veiga-Fernandes explains.
Research has shown that people who work shifts are more likely to develop certain long term health problems.
Researchers have linked having a regular sleep-wake pattern to lower risks of high blood pressure, obesity, and high cholesterol.
Those who work night shifts for a long time, for instance, have a higher risk of conditions such as ulcers, some cancers, metabolic illnesses, obesity, and gastrointestinal conditions.
“To understand why this happens,” Veiga-Fernandes continues, “we started by asking whether immune cells in the gut are influenced by the circadian clock.”
He and his colleagues found that ILC3s are particularly sensitive to changes in their clock genes, the genes that control rhythmic cell processes.
They also uncovered a circuit that links the circadian, or 24-hour, clock in the brain to ILC3s in the gut.
It appears that disruptions to this circuit, which senses changes in environmental light, can alter ILC3 clock genes. These genetic changes can impair the immune cells’ ability to regulate gut health.
The team demonstrated this effect by disrupting the 24-hour clock in the mice’s brains.
