An organism found in dirt may lead to an anxiety vaccine, say scientists

Can dirt help us fight off stress? Groundbreaking new research shows how.

An organism found in dirt may lead to an anxiety vaccine, say scientists
University of Colorado Boulder
  • New research identifies a bacterium that helps block anxiety.
  • Scientists say this can lead to drugs for first responders and soldiers, preventing PTSD and other mental issues.
  • The finding builds on the hygiene hypothesis, first proposed in 1989.


Are modern societies trying too hard to be clean, at the detriment to public health? Scientists discovered that a microorganism living in dirt can actually be good for us, potentially helping the body to fight off stress. Harnessing its powers can lead to a "stress vaccine".

Researchers at the University of Colorado Boulder found that the fatty 10(Z)-hexadecenoic acid from the soil-residing bacterium Mycobacterium vaccae aids immune cells in blocking pathways that increase inflammation and the ability to combat stress.

The study's senior author and Integrative Physiology Professor Christopher Lowry described this fat as "one of the main ingredients" in the "special sauce" that causes the beneficial effects of the bacterium.

The finding goes hand in hand with the "hygiene hypothesis," initially proposed in 1989 by the British scientist David Strachan. He maintained that our generally sterile modern world prevents children from being exposed to certain microorganisms, resulting in compromised immune systems and greater incidences of asthma and allergies.

Contemporary research fine-tuned the hypothesis, finding that not interacting with so-called "old friends" or helpful microbes in the soil and the environment, rather than the ones that cause illnesses, is what's detrimental. In particular, our mental health could be at stake.

"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," explained Lowry. "That has put us at higher risk for inflammatory disease and stress-related psychiatric disorders."

Christopher Lowry

University of Colorado Boulder

This is not the first study on the subject from Lowry, who published previous work showing the connection between being exposed to healthy bacteria and mental health. He found that being raised with animals and dust in a rural environment helps children develop more stress-proof immune systems. Such kids were also likely to be less at risk for mental illnesses than people living in the city without pets.

Lowry's other work also pointed out that the soil-based bacterium Mycobacterium vaccae acts like an antidepressant when injected into rodents. It alters their behavior and has lasting anti-inflammatory effects on the brain, according to the press release from the University of Colorado Boulder. Prolonged inflammation can lead to such stress-related disorders as PTSD.

The new study from Lowry and his team identified why that worked by pinpointing the specific fatty acid responsible. They showed that when the 10(Z)-hexadecenoic acid gets into cells, it works like a lock, attaching itself to the peroxisome proliferator-activated receptor (PPAR). This allows it to block a number of key pathways responsible for inflammation. Pre-treating the cells with the acid (or lipid) made them withstand inflammation better.

Lowry thinks this understanding can lead to creating a "stress vaccine" that can be given to people in high-stress jobs, like first responders or soldiers. The vaccine can prevent the psychological effects of stress.

What's more, this friendly bacterium is not the only potentially helpful organism we can find in soil.

"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," said Lowry. "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."

Check out the study published in the journal Psychopharmacology.

A brief history of human dignity

What is human dignity? Here's a primer, told through 200 years of great essays, lectures, and novels.

Credit: Benjavisa Ruangvaree / AdobeStock
Sponsored by the Institute for Humane Studies
  • Human dignity means that each of our lives have an unimpeachable value simply because we are human, and therefore we are deserving of a baseline level of respect.
  • That baseline requires more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose.
  • We look at incredible writings from the last 200 years that illustrate the push for human dignity in regards to slavery, equality, communism, free speech and education.
Keep reading Show less

Astrophysicists: Gamma-ray jets exceed the speed of light

Scientists find that bursts of gamma rays may exceed the speed of light and cause time-reversibility.

An artist's drawing of a particle jet emanating from a black hole at the center of a blazar.

Credit: DESY, Science Communication Lab (used with permission by Astronomy Picture of the Day, which is co-managed by Robert Nemiroff at Michigan Tech).
Surprising Science
  • Astrophysicists propose that gamma-ray bursts may exceed the speed of light.
  • The superluminal jets may also be responsible for time-reversibility.
  • The finding doesn't go against Einstein's theory because this effect happens in the jet medium not a vacuum.
Keep reading Show less

​'The time is now' for cryptocurrencies, PayPal CEO says

Is Bitcoin akin to 'digital gold'?

Technology & Innovation
  • In October, PayPal announced that it would begin allowing users to buy, sell, and hold cryptocurrencies.
  • Other major fintech companies—Square, Fidelity, SoFi—have also recently begun investing heavily in cryptocurrencies.
  • While prices are volatile, many investors believe cryptocurrencies are a relatively safe bet because blockchain technology will prove itself over the long term.
Keep reading Show less

"Clean meat" approved for sale in Singapore

Singapore has approved the sale of a lab-grown meat product in an effort to secure its food supplies against disease and climate change.

Credit: Adobe Stock / Big Think
Politics & Current Affairs
  • Singapore has become the first country to approve the sale of a lab-grown meat product.
  • Eat Just, the company behind the product, will have a small-scale commercial launch of its chicken bites.
  • So-called "clean meats" may reduce our reliance on livestock farming, which kills billions of animals worldwide every year.
  • Keep reading Show less
    Scroll down to load more…
    Quantcast