Scientists have isolated a unique molecular pattern that could one day enable the existence of a "stress vaccine" – and found it buried in a bacterium that thrives in the dirt.
Mycobacterium vaccae is a non-pathogenic bacterium that lives in the soil and has shown promise in health research. Now a new study might finally have figured out why.
The results suggest that a particular type of fat in M. vaccae could be the reason why it might be good for us to be exposed to this apparently beneficial bacterium in the soil.
This work ties in with the idea of "old friends," a hypothesis stating that man has evolved useful microorganisms along with a group of humans, and the loss of these bonds in the modern environment has led to an increase of allergic and autoimmune diseases.
"The idea is that when people moved to cities from farms and agricultural or hunter-gatherer livelihoods, we lost contact with organisms used to regulate our immune system and suppress inappropriate inflammation," he says Neuroendocrinologist Christopher Lowry.
"This exposes us to a higher risk of inflammatory diseases and stress-related psychiatric disorders." M. vaccae . In a previous study, it was found for years that injecting a heat-killed bacterial preparation into mice prevented the occurrence of stress-induced responses in animals.
But so far no one was sure what it was in M. Vakzae who could be responsible for such effects.
"One of the burning questions is essentially what critical constituents of the bacteria seem to benefit the host." Lowry reported the Denver Post .
In the new study, researchers isolated and synthesized a fatty acid called 1
At the molecular level, the lipid appears to bind to receptors termed peroxisome proliferator-activated receptors (PPARs). In this way inflammatory pathways are inhibited – at least in experimentally treated immune cells of the mouse.
"It seems that the bacteria we've worked with have a trick on their sleeve," says Lowry.
"When ingested by immune cells, they release these lipids that bind to this receptor and switch off the inflammatory cascade."
Much work would still be required to see if the same effect is replicated in humans could. If possible, researchers may use this discovery to develop a "stress vaccine" that will help people in high-stress occupations at risk of developing post-traumatic stress disorder.
According to current research, this is still a long way off. Lowry, however, is quite optimistic and estimates that it will be 10 to 15 years before such treatment is available. If he is right, we have mistakes in the dirt that we can thank.
"We used to think that microbacteria are not an important part of the human microbiome," said Lowry the Denver Post . 19659004] "The power of nature surprises and surprises us as scientists time and again, and we look forward to learning more."
The results are reported in Psychopharmacology .