Bacteria are everywhere, from the fat railing that you touched this morning to the bottom of the seabed, not to forget the trillion or so Fortunately, living along your intestinal tract. But it has long been thought that the brain of a healthy person is a safe haven away from the germs world.
Now, a potentially revolutionary part of research indicates that there are bacteria in our brain, a discovery that can have some real feelings. If this preliminary study is about the money, it can explain the obvious effect the bowel bacteria have on our brain function, behavior and emotions.
A team of neurobiologists from the University of Alabama presented its preliminary results at the annual meeting of the Society for Neuroscience last week.
The idea of healthy brains carrying their own microbiota has been floats around for a while, but researchers have never been able to establish any strong evidence. In this study, they saw samples of 34 murderers, of whom half belonged to schizophrenia Science – and discovered everything of the brains contained varying amounts of rod-shaped bacteria. Most bacteria were placed in substantia nigra, hippocampus and prefrontal cortex, with less numbers in the striatum.
To eliminate the possibility of the presence of bacteria, the result of intestinal bacteria sipping into the brain after death, the researchers then analyzed a number of sterilized mice, as they treated in exactly the same way, and found that no contamination with bacteria had occurred. This suggests, albeit not definitely, that human brains did not contain bacteria due to contamination after death.
Perhaps most fascinating of all, the bacteria were the same types that you would expect to find in the intestines, for example Firmicutes, Proteobacteria, and Bacteroidetes.
The detection of bacteria in the brain is particularly curious due to the blood-brain barrier, a fastening of cells near the brain's blood vessels that protects it from unwanted invaders. If any pathogen, like bacteria, does it through this barrier, it can lead to life-threatening inflammation. However, the newly discovered bacteria do not seem to have such effect.
"Interestingly there were no structural signs of inflammation in any of the examined brains," wrote the researchers in an abstract for the presentation. "It is currently unclear the route of entry into bacteria takes to the brain, but the evidence of those in axon and in the blood-brain barrier supports previous speculation."
So, how did the bacteria enter the brain? Are they from the intestines? Do they in any way affect the brain's activity? The researchers are not sure of any of these issues because there are still very early days for research. But with further research into the supposed "brain microbiomy" they hope to open the door to the deeply mysterious relationship between bacteria, our intestines and our brains.