Under the Hood

Can Poop Be Used To Treat Depression?

Scientists have found that transplanting feces from one source to another patient could potentially help treat psychiatric disorders such as depression. But don’t worry, it is not what you think. There is a “clean” and safe way to get fecal transplants.

A new study published in the journal Molecular Psychiatry shows that in animals, transplanting gut bacteria from non-stressed subjects to those exposed to stress could improve the latter’s mental condition. Researchers said their findings could help create probiotic treatments for human psychiatric disorders.

"In rats that show depressive-type behavior in a laboratory test, we found that stress changes their gut microbiome — the population of bacteria in the gut," Seema Bhatnagar, lead researcher and a neuroscientist in Department of Anesthesiology and Critical Care at Children's Hospital of Philadelphia (CHOP), said in a statement. 

Prior to the study, it has been known that the brain and gut influence each other. In humans, patients with psychiatric disorders have unique gut microbes in their bodies compared to microbes in healthy individuals. Bhatnagar’s team focused on the mechanisms related to brain inflammation, microbiomes and stress.

For their study, the researchers analyzed the fecal microbiomes of stressed rats, resilient rats, a non-stressed control group and a placebo group. Results showed that the animal subjects with mental issues had higher proportions of certain bacteria, such as Clostridia, than the other groups.

The stressed group then received fecal transplants from three healthy donor groups that never experienced stress. The researchers found that foreign microbiomes changed depressive-like behavior in the recipients. 

However, the transplant did not lead to any changes in the behavior of rats with anxiety. The team suggested depressive-type behaviors are more regulated by the gut microbiome while anxiety-type behaviors may be influenced by neural activity changes produced by stressful experiences.

"Although much more research remains to be done, we can envision future applications in which we could leverage knowledge of microbiome-brain interactions to treat human psychiatric disorders," Bhatnagar said. "If we can eventually validate beneficial behavioral effects from specific bacteria, we could set the stage for new psychiatric treatments."