MAY 29, 2019 10:04 AM PDT

Healthy Fat From a Beneficial Microbe May Help us Relieve Stress

WRITTEN BY: Carmen Leitch

Even though the developed world has access to plenty of cleaning and hygiene products, it is still full of diseases, and children that live in cleaner households actually tend to have higher rates of some chronic illnesses like asthma. The hygiene hypothesis was presented as a potential explanation for these observations; the immune system doesn’t get properly stimulated by germs early on in life and can lead to autoimmune problems later. Recent work has illustrated that we all carry around tons of microbes in and on our bodies, and these bugs have a significant impact on our physical and mental health (as discussed in the video below).

Christopher Lowry. / Credit: CU Boulder

Scientists at the University of Colorado Boulder have now found that a microbe that lives in soil generates a fat that has anti-inflammatory properties. This bacterium, Mycobacterium vaccae, may be a very beneficial microbe that can help reduce stress and anxiety. The findings have been reported in Psychopharmacology.

"We think there is a special sauce driving the protective effects in this bacterium, and this fat is one of the main ingredients in that special sauce," said the senior author of the study, Integrative Physiology Professor Christopher Lowry.

Researchers have spent years refining the hygiene hypothesis, and work has indicated that a lack of exposure to beneficial microbes, so-called ‘old friends,’ is the real problem. That reduction in contact with good bugs may also be disruptive to mental health.

"The idea is that as humans have moved away from farms and an agricultural or hunter-gatherer existence into cities, we have lost contact with organisms that served to regulate our immune system and suppress inappropriate inflammation," said Lowry. "That has put us at higher risk for inflammatory disease and stress-related psychiatric disorders."

Lowry has investigated the connections between bacteria and mental health for a long time. He has shown in previous work that rural kids have immune systems that are more resilient to stress and might be at lower risk for mental illness than urban kids that live without pets. His team has also found that when rodents are exposed to M. vaccae their reaction resembles the effect of antidepressants, and anti-inflammatory effects are seen in the brain. Brain inflammation is thought to raise the risk of disorders like posttraumatic stress disorder (PTSD) that have been linked to stress. When mice were injected with M. vaccae before a stressful event occurred, a "PTSD-like" mouse syndrome was less likely to happen.

"We knew it worked, but we didn't know why," said Lowry. "This new paper helps clarify that."

In this new research, the investigators isolated a novel fatty acid found in M. vaccae called 10(Z)-hexadecenoic acid. When immune cells called macrophages were stimulated, the fatty acid attached to a receptor called PPAR and inhibited cellular pathways that promote inflammation.

"It seems that these bacteria we co-evolved with have a trick up their sleeve," said Lowry. "When they get taken up by immune cells, they release these lipids that bind to this receptor and shut off the inflammatory cascade."

Lowry imagines using the microbe to create a "stress vaccine" that could be given to people in psychologically demanding roles in order to prevent the damage stress can cause. More work will be needed in people to confirm that the fat has this impact, but if it works on its own, it might be useful in drug development. The active compound and its receptor have both been identified, Lowry noted.

"This is just one strain of one species of one type of bacterium that is found in the soil but there are millions of other strains in soils," Lowry said. "We are just beginning to see the tip of the iceberg in terms of identifying the mechanisms through which they have evolved to keep us healthy. It should inspire awe in all of us."


Sources: AAAS/Eurekalert! via University of Colorado Boulder, Psychopharmacology

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 11, 2020
Microbiology
JAN 11, 2020
Twins Still Have Microbial Strains in Common After Living Apart for Years
Twins can offer researchers an opportunity to study health and biology in people with the same genes, raised in the same environment....
JAN 26, 2020
Microbiology
JAN 26, 2020
The Planet's Soil is Home to Microbe-Eating Protists
Protists don't fit neatly into any other category of organism; they are eukaryotes, but they are not a plant, fungi or animal....
FEB 05, 2020
Clinical & Molecular DX
FEB 05, 2020
A new CRISPR-based test for coronavirus infections
A surge in infections has caused panic surrounding the coronavirus (2019-nCoV) outbreak to reach a fever pitch. Despite being only moderately infective, 20...
MAR 15, 2020
Microbiology
MAR 15, 2020
COVID-19 - What To Do If You Get Sick
It now seems that the SARS-CoV-2 virus is spreading through communities in many places worldwide....
MAR 27, 2020
Chemistry & Physics
MAR 27, 2020
Hand Sanitizer Shorage: Liquor, Perfume, and Medication Producers Joined the Race to Restock the Shelves
Amid the coronavirus pandemic, the habit of thorough and frequent handwashing are among the best defense against the contagious disease. But when soap and water aren't available, hand sanitiz...
MAR 31, 2020
Microbiology
MAR 31, 2020
Researchers Suggest Repurposing Pancreatitis Drug to Treat COVID-19
As SARS-CoV-2 upends normalcy in the world, researchers are trying to find a treatment for the illness it causes....
Loading Comments...