SEP 06, 2019 5:48 PM PDT

Antidepressants and Serotonin Impact Gut Microbiota

WRITTEN BY: Carmen Leitch

The microbes that live in our gastrointestinal tract have been shown to have a powerful influence on many aspects of our health. The stuff we consume can also get digested those microbes, affecting them in turn. New research by scientists at UCLA has indicated that drugs targeting the neurotransmitter serotonin and serotonin itself can have a significant impact on the microbes in our gut; bacteria can take up the neurotransmitter. Serotonin influences emotion and plays many roles in human physiology; it is a critical signaling molecule. About 90 percent of the serotonin found in the human body is made in the gut.

Image credit: Modified from Max Pixel

"Our previous work showed that particular gut bacteria help the gut produce serotonin. In this study, we were interested in finding out why they might do so," explained Elaine Hsiao, UCLA assistant professor of integrative biology and physiology, and of microbiology, immunology and molecular genetics in the UCLA College; and of digestive diseases in the David Geffen School of Medicine at UCLA.

Led by Hsiao and postdoctoral fellow Thomas Fung, researchers conducted a mouse study in which they studied a specific gut microbe called Turicibacter sanguinis, which senses serotonin and can move it into bacterial cells.

When mice were exposed to Prozac (a selective serotonin reuptake inhibitor), less serotonin was moved into their gut bacteria. The findings have been reported in Nature Microbiology.

Previous work by Hsiao’s team has shown that when mice were given a mixture of bacteria including Turicibacter sanguinis and Clostridia, molecules were generated that trigger an increase in serotonin production in gut cells. If mice lacked these two types of microbes, their guts lost over 50 percent of the usual amount of serotonin. Adding the bacterial mixture back restored their serotonin levels to normal.

The researchers began to wonder why microbes want gut cells to release serotonin. They exposed some mice to extra serotonin in drinking water, and genetically engineered others to increase gut serotonin levels. The scientists found that the levels of Turicibacter and Clostridia bacteria were significantly increased after the gut serotonin levels were raised by either method.

"Previous studies from our lab and others showed that specific bacteria promote serotonin levels in the gut," Fung said. "Our new study tells us that certain gut bacteria can respond to serotonin and drugs that influence serotonin, like anti-depressants. This is a unique form of communication between bacteria and our own cells through molecules traditionally recognized as neurotransmitters."

This work is in agreement with other studies that have demonstrated the influence of antidepressants on the gut microbiome. "For the future, we want to learn whether microbial interactions with antidepressants have consequences for health and disease," added Hsiao.

The video above from Yale University outlines recent work that shows how gut bacteria influence drug efficacy, and can help explain why drugs often have very different impacts on different individuals.

Sources: Phys.org via University of California, Los Angeles, Nature Microbiology

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
JAN 27, 2020
Microbiology
JAN 27, 2020
Microbes in Household Dust May Be Spreading Antibiotic Resistance
Bacteria live in household dust, and sometimes a few of those microbes are pathogenic or carry genes that confer resistance to antibiotics....
FEB 08, 2020
Drug Discovery & Development
FEB 08, 2020
Drug Targets Brain-Eating Amoebas
Brain-eating amoebas lead to high rates of mortality as a result of encephalitis. In fact, more than 95% of people who develop the infection will die. Unfo...
FEB 22, 2020
Neuroscience
FEB 22, 2020
Does Your Gut Bacteria Influence Your Personality?
A researcher from Oxford University, UK, has found that certain gut bacteria may be able to influence our personality traits via the microbiome-gut-brain a...
MAR 08, 2020
Microbiology
MAR 08, 2020
A Supercomputer Aids in the Hunt for COVID-19 Therapeutics
It is seeming more likely that COVID-19, caused by the coronavirus SARS-CoV-2, will impact many people....
MAR 18, 2020
Microbiology
MAR 18, 2020
The Coronavirus SARS-CoV-2 is Stable for Hours on Surfaces
SARS-CoV-2 is a coronavirus that causes an illness called COVID-19. There are now well over 210,000 confirmed cases worldwide....
APR 05, 2020
Microbiology
APR 05, 2020
How Life Beneath the Sea Informs the Search for Life on Mars
Single-celled microbes that live beneath the floor of the ocean have provided insight into how scientists might be able to find life on Mars....
Loading Comments...