A study has shown how the microbes in one’s gut help manage stress by interacting with the body’s circadian rhythm, or biological clock.
Researchers at University College Cork, Ireland, found that the trillions of microorganisms in the gut – or the gut microbiome – regulate hormones produced in response to stress in a time-dependent manner.
The team said that a healthy gut helps create a day-night rhythm in the production of stress hormones, while a depleted gut microbiome disrupts the body clock and is related to altered rhythms in the production of stress hormones.
The findings, published in the journal Cell Metabolism, highlight the importance of maintaining a healthy gut, he said.
The researchers said the study’s results could also be used to develop treatments for mental conditions such as anxiety and depression, which are known to be linked to stress and often involve disrupted body clocks and sleep cycles.
“Our research has revealed an important relationship between the gut (microbiome) and how the brain responds to stress in a time-specific manner,” said lead researcher John Cryan, of University College Cork.
“The gut microbiome doesn’t just regulate digestion and metabolism; it plays a critical role in our response to stress, and this regulation follows a precise circadian rhythm,” Cryan said.
For the study, researchers looked at mice, which are known to have similar biological processes and genetic material to humans.
The team found a “complex relationship” between gut microbes and the three regions that make up the HPA axis in the brain – the hypothalamus, the pituitary gland and the adrenal gland. The HPA axis is the body’s central stress response system.
Researchers showed that depletion of the gut microbiome results in the HPA axis being overactivated in a manner specific to the time of day. This, combined with changes in brain areas that respond to stress and changes in the biological clock, alters the body’s response to stress throughout the day, he said.
Specific gut bacteria, including Lactobacillus strains (Lymolactobacillus reuteri) were identified as “key effectors” of this body clock-related stress response.
