Researchers at the University of Victoria in Canada say a naturally occurring protein called Reelin may help explain how chronic stress can affect both the gut and the brain. Their findings, published in the journal Chronic Stress, point to Reelin as a potential target for future treatments aimed at gut barrier damage and depression-related symptoms.
The study focuses on the gut barrier, the lining that controls what passes from the intestines into the bloodstream. Under prolonged stress, that barrier can become more permeable, a process often described as leaky gut, which may allow bacterial components to enter circulation and trigger immune inflammation.
How stress may lower Reelin
In preclinical experiments, the team observed that chronic stress was associated with reduced Reelin levels in intestinal tissue. When researchers administered a single small dose of Reelin, levels in the intestine returned to what the scientists described as normal ranges in their model.
The authors argue the result matters because gut inflammation is increasingly studied as a contributor to mood disorders through the gut-brain axis. In this framework, immune signals and inflammatory processes can influence brain function, potentially worsening depression in vulnerable people.
Why the gut-brain link matters
Previous research has reported lower Reelin levels in brain tissue among people diagnosed with major depressive disorder, and similar patterns have been seen in stressed animal models. In earlier preclinical work cited by the team, Reelin administration was linked with antidepressant-like effects, though this does not yet demonstrate clinical benefit in humans.
The researchers also highlight that the intestinal lining typically renews rapidly, roughly every few days, to maintain an effective barrier. They suggest Reelin may support this renewal process, which could help prevent barrier breakdown and reduce inflammation-driven effects that can intersect with depression.
What comes next for Reelin research?
Scientists caution that translating these findings into a therapy would require extensive follow-up, including safety studies, dosing work, and eventually human clinical trials. For now, the study adds to growing evidence that treating depression may, in some cases, involve addressing biological processes outside the brain, including gut integrity and immune activation.
The research was supported by funding from Canada’s federal granting agencies, including the Canadian Institutes of Health Research and the Natural Sciences and Engineering Research Council of Canada. The authors say further studies will be needed to clarify how Reelin works across tissues and whether it can be developed into a practical medical intervention.
