About Microbiome

Harvard researchers have found that M. morganii may contribute to depression by producing an inflammatory molecule.

Biochemical analyses reveal how the gut bacterium Morganella morganii may contribute to some cases of major depressive disorder.
The bacterium incorporates an environmental contaminant into one of its molecules, triggering inflammation — a known factor in disease development.
These findings suggest the contaminant could serve as a biomarker and further support the idea that major depressive disorder may have autoimmune connections.

Unraveling the Gut-Brain Connection

Researchers are uncovering more evidence that the gut microbiome plays a crucial role in overall health, including mental well-being. However, identifying which bacteria contribute to disease and understanding their exact mechanisms is still in its early stages.

One bacterium of interest is Morganella morganii, which has been linked to major depressive disorder in several studies. Until now, it was unclear whether this bacterium contributes to the disorder, whether depression alters the microbiome, or if another factor is involved.

A Breakthrough in Brain Health Research

A team from Harvard Medical School has now identified a biological mechanism that strengthens the case for M. morganii’s role in brain health. Their findings offer a plausible explanation for how this bacterium may influence mental health.

Published on January 16 in the Journal of the American Chemical Society, the study points to an inflammation-triggering molecule that could serve as a potential biomarker for diagnosing or treating some cases of depression. More broadly, the research provides a roadmap for investigating how other gut microbes impact human health and behavior.

“There is a story out there linking the gut microbiome with depression, and this study takes it one step further, toward a real understanding of the molecular mechanisms behind the link,” said senior author Jon Clardy, the Christopher T. Walsh, PhD Professor of Biological Chemistry and Molecular Pharmacology in the Blavatnik Institute at HMS.

Credit goes to Stephanie Dutchen, Harvard Medical School