Gut Feeling: Researchers Are Discovering a Link Between Depression and Gut Bacteria

Gut microbiota dysbiosis-mediated ceramides elevation contributes to corticosterone-induced depression by impairing mitochondrial function

The role of gut microbiota (GM) dysbiosis in the pathogenesis of depression has received widespread attention, but the mechanism remains elusive. Corticosterone (CORT)-treated mice showed depression-like behaviors, reduced hippocampal neurogenesis, and altered composition of the GM. Fecal microbial transplantation from CORT-treated mice transferred depression-like phenotypes and their dominant GM to the recipients. Fecal metabolic profiling exposed remarkable increase of gut ceramides in CORT-treated and recipient mice. Oral gavage with Bifidobacterium pseudolongum and Lactobacillus reuteri could induce elevations of gut ceramides in mice. Ceramides-treated mice showed depressive-like phenotypes, significant downregulation of oxidative phosphorylation-associated genes, and hippocampal mitochondrial dysfunction. Our study demonstrated a link between chronic exposure to CORT and its impact on GM composition, which induces ceramides accumulation, ultimately leading to hippocampal mitochondrial dysfunction. This cascade of events plays a critical role in reducing adult hippocampal neurogenesis and is strongly associated with the development of depression-like behaviors.

Gut Microbiome and Depression: How Microbes Affect the Way We Think

The gut microbiome serves an important role in the human body. Reportedly, one of the benefits of these microflora is on mental health. Once established, food and other dietary sources that enhance quality microbiome content in our gastrointestinal system will be a significant consideration in individuals’ day to day lives. This literature review conducted a PubMed search for studies about the gut microbiome and its relation to depression. In using several Medical Subject Heading (MeSH) keywords, relevant literature was selected. A total of 26 articles were selected after applying the inclusion and exclusion criteria, and after checking the articles’ accessibility. This literature would like to establish the role of the gut microbiome in depression. This study's findings showed that there is a strong association of microbiome function to mental well-being.

Microbial Treatments for the Mind

For $99, you can obtain a kit that includes two cotton swabs and instructions for properly collecting your own stool sample, along with oral and skin samples. Upon shipping those specimens to the Knight Lab in La Jolla, CA, you will join the ranks of "citizen scientist," becoming a contributor to the world's largest crowd-sourced microbiome research project. In return, should you have accepted this mission, you will receive a report that offers you a "snapshot" of the microbes found in your fecal matter, and compares it to that of the rest of the population.