▲ 192 points
back
67 comments
This is all very preliminary, a couple of quotes from the article stood out to me:
> Roberts wondered whether bacteria from the gut could have leaked from blood vessels into the brain in the hours between a person’s death and the brain’s removal.
> Roberts acknowledges that her team still needs to rule out contamination. For example, could microbes from the air or from surgical instruments make it into the tissue during brain extraction?
But you left off supporting evidence from mouse models: "So she looked at healthy mouse brains, which were preserved immediately after the mice were killed. More bacteria. Then she looked at the brains of germ-free mice, which are carefully raised to be devoid of microbial life. They were uniformly clean."
I had no idea we could sustain germ-free life. That's so cool. The obvious evidence that seems to be missing, however, would just be to extract brain tissue from a living animal, no?
that very much contradicts my model of organisms as well.
I thought we ARE 95% germs, DNA wise.
Prokaryotes are thousands of times smaller in mass/volume, so most cells (and maybe even most DNA) can be bacteria while these are nonetheless minor players.
That does nothing to rule out contamination from a different tissue.
Different methods. Same result. But sure, you can't prove a negative.
How could one possibly rule out contamination by this logic?
By using some procedure that controls for contamination from a different tissue, instead of having no relation to it.
The truth is that it will probably be hard to find conclusive evidence unless we look for this in a living brain.
Would be fascinating if it turns out to be half as important as gut bacteria. Maybe certain human breakthroughs like the rise of civilization could one day be attributed to a bacterial infection. And then the inverse, changing diets and the brain biome might lead to their collapse.
I've thought the same of viruses as well. If the Zika virus can cause brain damage, perhaps there was another virus (and/or microbe) at some point that made us smarter.
Maybe its bacteria from periodontal disease
"DNA from the periodontal bacteria was also found in the brain tissue of mice in the study group, and a bacterial protein was observed inside their neurons."
https://medicalxpress.com/news/2018-10-periodontal-disease-b...
I know it is just pain radiating from the nerves of the tooth, but a couple times when I had a tooth go abscessed the pain was so intense and in my head I kept thinking my upper mouth is so close to my brain surely this infection can make it from my tooth into my brain. I know about the blood brain barrier but I kept thinking surely it is just a defense and not perfect and a bad infection could push its way in.
Infections in the facial area can indeed be quite serious:
https://skeptics.stackexchange.com/questions/10674/can-poppi...
On that note, a warning:
Do NOT pluck your eyelashes or nose hairs, ever!! These hair roots can cause the trigeminal nerve to become infected which can then lead to meningitis/brain infection and ultimately retardism/coma/death.
Trim if you must -- and do not use a powered trimmer either! The so called "no-pull" nose hair trimmers still cut too short or pull hairs anyways, leading to infection.
Solution: just use mini cat nail scissors. They are actually perfect shape and size to cleave nose hairs at a good length without risk of infection.
If you appreciate quality Japanese craftsmanship that will last a lifetime, I recommend Cattyman. My cats and my nose swear by them. And it's the only brand we carry at the shelter that I volunteer at. [1]
Source: I am a med student and graduated with honors in Biomedical Sciences
I think we have all kinds of latent bacteria and viruses in our body (including the brain). It's however a interesting though that there might be good brain bacteria, which might affect feelings, emotions, and alertness.
I already see my local dairy industry make money out of this: "Drink our new Brainimel, with the best microbiome for your brain, so you can stay asleep, obey and consume..."
I once had the horror of walking through some drug store and seeing bottled DNA, with a description like "an essential component of life!" At best, I suppose it was an overpriced and inefficient amino acid supplement. At worst, it was effectively a sugar pill.
I'm sure that these studies get any traction, we'll see bacterial 'supplements' almost immediately. Never mind that even gut microbiome supplements are usually destroyed in the stomach, we can definitely make yogurt that gets to your brain!
Where do you live that you have such an aggressive dairy industry?
You haven't heard of Hyperbole Town, have you? :)
Seems to me that the more we sharpen our mental and methodological tools (in all areas of human inquiry), the weirder and more interesting things become.
Shit's messy, yo!
Can't wait to order some "cerebral-probiotics 2000"
We'll all laugh now but come the incessant infomercials (I'm guessing 2-3 years) and interstitials it won't be so funny.
It would be interesting to find out that a lot of modern psychological diseases might be caused by excessive antibiotic use disrupting the brain microbiome.
There is evidence to suggest antibiotics increase risk of anxiety and depression.
Can antibiotics pass the blood brain barrier?
Some do, including penicillin:
“Antibiotics that cross the BBB tend to have certain physical characteristics including: small molecular size, being lipophilic, binding to fatty molecules on cell membranes, low plasma protein binding and other specialized characteristics“
http://lymemd.blogspot.com/2013/03/blood-brain-barrier.html?...
Antibiotics can certainly cause problems in the gut microbiome, but let's not jump to conclusions about the brain just yet.
A lot of people who started eating exclusively meat reported their depression, anxiety and (mental) fatigue going away, so this is should not be surprising.
I can't believe you people haven't brought up the obvious zombie-gut microbiome connection yet...
How is it possible we didn't notice anything like this before?
reminds me of https://en.wikipedia.org/wiki/Archaea
Although these archaea can be present in extremely high numbers (up to 40% of the microbial biomass), almost none of these species have been isolated and studied in pure culture.
Most likely because someone failed to look for it before or those that saw it assumed it was contamination.
Wait a second, how did bacteria get through the blood-brain barrier?
In that case the barrier is likely semipermeable. It may be that certain bacteria were advantageous to human evolution, so the barrier evolved with a mechanism that allowed good bacteria to pass through. Now this should make us humans a bit concerned about the likelihood of mimics. If good bacteria indeed play a role in human emotion and alertness, then perhaps some mimics result in certain types of mental illness.
Bacteria associated with meningitis get through with predictable results so what else might?
I do not know a lot about bacterial meningitis, but I don't believe that it actually passes through the barrier. Meningitis is caused by the inflammation of a membrane that the brain and spinal chord are encased within [1]. So it might be causing the membrane to become enflamed from the outward facing surface.
[1] https://www.healthline.com/health/bacterial-meningitis-cause...
There has been some potentially revolutionary work at CalTech with respect to the link between intestinal bacterial and Parkinson's (see link below). If it pans out it could potentially open up entirely new avenues of treatment.
http://www.caltech.edu/news/parkinsons-disease-linked-microb...
Pesticides and plasticizers are known to disturb the blood-brain barrier and allow poisonous substances (and apparently bacteria?) to infiltrate brains.
maybe the barrier is not that leak-proof as current medical postulates? Maybe it's not a barrier after all, just a border?
How is babby formed!??
Seriously, is it possible the brain is infected (innoculated maybe?) in utero before the blood brain barrier is formed, or before the skull is formed.
That would be cool: if mothers passed on a colony of bacterias that evolved down the generations.
Everything has limits and fails. So yeah, probably this.
By being the same size or smaller than the passages in the barrier.
The blood brain barrier usually only allows particles on the order of nanometers in size, while bacteria are much, much larger.
Marketers lickicking their chops for Yogurt for brain campaigns
Incredible.
What a great idea.
FWIW, that wasn't sarcasm.