Bacteria in the gut play a key role in the control of stress throughout the day, by interacting with the body’s internal clock, a study in mice has found.
The research, conducted by APC Microbiome Ireland, a Research Ireland Centre at EARA member University College Cork, looked at the daily changes of natural gut bacteria (the gut microbiome) in healthy mice and in mice that had had certain gut bacteria missing due to the introduction of antibiotics.
In the mice with a depleted microbiome, the researchers saw that there were increased levels of a stress hormone (corticosterone) in the body, as well as altered patterns in the HPA axis – the central stress response system that connects parts of the brain to other parts of the body.
Meanwhile, it was observed that the activity of stress-related genes in the brain was also disrupted, and the depleted mice did not show reduced social interaction during stress (the normal, expected behaviour).
This suggests a role for gut bacteria in controlling the response to stress. The researchers also saw that the changes were linked to the body’s 24-hour ‘internal clock’ (circadian rhythms), which shows this stress regulation follows a precise, time-dependent pattern.
Senior author John Cryan (pictured left, with Gabriel Tofani) said: “These findings underscore the importance of maintaining a healthy microbiome, particularly for those living in today’s stressful and fast-paced environment.”