A Baffling Brain Defect Is Linked to Gut Bacteria, Scientists Say (sciencealert.com)

Gina Kolata from The New York Times writes about a baffling brain disorder that is linked to a particular type of bacteria living in the gut (Warning: source may be paywalled; alternate source) The new study, published on Wednesday in Nature, is among the first to suggest convincingly that these bacteria may initiate disease in seemingly unrelated organs, and in completely unexpected ways. The researchers studied hereditary cerebral cavernous malformations -- blood-filled bubbles that protrude from veins in the brain and can leak blood or burst at any time. When Dr. Mark Kahn, professor of cardiovascular medicine at the University of Pennsylvania's Perelman School of Medicine, began this work, the microbiome was the last thing on his mind. Dr. Kahn and his colleagues studied cerebral cavernous malformations as part of a larger effort to understand the development and function of blood vessels. Three genes have been linked to the disorder, and Dr. Kahn and his colleagues tried to figure out what these mutations really do. The scientists were able to mimic the condition in mice by deleting a gene that is mutated in many patients. A year ago, the scientists moved to a new building, and something unexpected happened. The experimental mice stopped developing the brain malformations. Dr. Kahn's student, Alan T. Tang, had been deleting the gene by injecting a drug into the abdomens of the mice. Sometimes a mouse would get an infection that would lead to an abscess, and bacteria leaked from the gut into the blood. In the new building, only those mice still developed the brain defect. The other gene-deleted mice did not. He and his colleagues finally identified the culprit: Gram-negative bacteria, named for the way they stain, that carry a molecule in their cell walls, a lipopolysaccharide. Without a functioning gene, the lipopolysaccharide can signal veins in the brain to form blood bubbles.

Comments

Dyslexia strikes again.

[Gravis Zero]

A Baffling Brain Defect Is Linked to LinkedIn...

I knew was something wrong with the people that use LinkedIn! ;)

Possibly other diseases?

[ArmoredDragon]

Curious if we have a similar cause from Parkinson's or ALS, the later of which has seemingly no identifiable congenital cause.

I recall when nobody knew that bacteria caused ulcers, and this was long after we knew about bacteria.

Re:Possibly other diseases?

[ShanghaiBill]

Parkinson's has some connections to the gut. For instance, it is correlated with constipation. Also people who drink a lot of coffee or tea are less likely to be afflicted. But I don't think it is cause by bacteria, because there is no cure. If gut bacteria caused the disease, some people would be cured inadvertently when they take high doses of antibiotics for other reasons, and that doesn't happen.

Re:Possibly other diseases?

[Anonymous Coward]

Alternatively, what if taking antibiotics wipes out good intestinal flora, resulting in these maladies in some patients? Diet can also affect intestinal flora, so that is a factor to consider too. Perhaps a poor diet wipes out the good bacteria or causes the bacteria to generate harmful waste products?

I think scientists have yet to discover the full extent of intestinal flora's relationship with overall bodily health and mental health (I think the enteric nervous system plays a role in the latter as well). It's very exciting when I read articles like this about scientists researching the topic, because I think they are very close to making a breakthrough in understanding how digestion/diet affects overall health.

Re:Possibly other diseases?

[Impy the Impiuos Imp]

Yes but the science was well against it all along, and the guy who claimed it had a financial interest in developing something lawyers could sue over.

Meanwhile, Jonas Salk died thinking his polio vaccine introduced AIDS to humans. His original vaccine, used only about a year before better ones came out, was created using monkey kidneys, which he feared may have had the simian AIDS believed to have spawned it.

We now know it preceded that date in humans by decades, but how horrible to think one of the greatest triumphs was also a deadly stroke.

Re:Possibly other diseases?

[Quince alPillan]

Or even like in this case where there's a genetic cause and a gut flora cause. It takes both scenarios in combination to cause the disease, which is why it's hard to reproduce an exact cause.

Re:Possibly other diseases?

[Vegan Cyclist]

This. (I don't know why you were downvoted, I think you're right on target.)

Let's just look at something that's seemingly common: fiber. About 97% of the US doesn't eat their daily recommended amount of fiber. What do the good flora like to eat? Fiber.

And this isn't to say Parkinson's (and other diseases) can be cured this way, but may be alleviated in some ways (which can still be really meaningful) with a more positive gut situation....and in a really easy way.

Re:Possibly other diseases?

[rogoshen1]

a disease that is entirely preventable, and transmitted through risky behavior (in probably 95% of cases?) vs a disease that maims and scars children for life -- even if Salk's vaccine had caused AIDS, it probably still would have been a net positive. Hopefully he took a bit of comfort in that calculus (as bleak and depressing as it may be.)

Re:Possibly other diseases?

[Alsn]

But I don't think it is cause by bacteria, because there is no cure. If gut bacteria caused the disease, some people would be cured inadvertently when they take high doses of antibiotics for other reasons, and that doesn't happen.

As a medical student I can say that while common sense and gut feeling would seemingly agree with you, the science of how our bodies work does not. Bacteria do not have to be directly present in order to cause problems. As an example you can take blood types, which most people are familiar with (A, AB, O). The antibodies that you have against the surface proteins of red blood cells of the different types are actually antibodies that are created against gut bacteria. However, mechanisms exist in each of us such that we do not develop antibodies against proteins that exist on our own cell structures, thus hindering our immune system from attacking our own proteins and cells.

This system is not fail-safe however and many auto-immune - where the body attacks itself - diseases exist (the field of rheumatology especially deals with a lot of these diseases). In short, just because antibiotics may wipe out a particular strain of gut bacteria that is present, the effect of that gut bacteria may indeed persist through many diverse mechanisms (of which the above is only one example), some of which we don't yet fully understand, as hinted at by this paper.

Re:Possibly other diseases?

[luis_a_espinal]

Parkinson's has some connections to the gut. For instance, it is correlated with constipation. Also people who drink a lot of coffee or tea are less likely to be afflicted. But I don't think it is cause by bacteria, because there is no cure. If gut bacteria caused the disease, some people would be cured inadvertently when they take high doses of antibiotics for other reasons, and that doesn't happen.

Damage caused by bacteria could be irreversible. So even if you kill the germs, the damage remains, incurable.

CCM for short

[PopeRatzo]

Cerebral Cavernous Malformations was the name of my punk rock band in college.

Re:CCM for short

[dr.Flake]

Now you know why everybody thought you guys played like shit

Re:CCM for short

[rogoshen1]

they were just waiting for their big break. (Alternatively to burst out onto the scene?)

Wakefield discovered this and was villified...

[Anonymous Coward]

Google Wakefield's discovery of the gut-brain connection in the 90s.

He was destroyed by media and scientists around the world, yet they didn't even seem to notice he wasn't even studying vaccines at all.

Take some time to listen to a very reasonable explanation about his discovery. If you can be patient hearing about anti-vaccine slant, you will hear a fascinating story of discovery about the gut-brain connection.

https://www.youtube.com/watch?v=SeMXlh-f7p8

He's a calm and reasonable man that explains simply and clearly what he did and how he came to his conclusions. If we could all be patient and calm, and listen to all sides of an argument, we may end up at the truth sooner (20 years ago) instead of just today...

Re:But how do we control this?

[Anonymous Coward]

With "ADHD, Asperger's, depression, and panic attacks" it seems high risk to pursue a job as a pilot, which the depression and panic attacks might disqualify you for.

Meanwhile you mention the engineering satisfying your inner geek.
May I suggest looking into becoming an aircraft mechanic?
Pay is pretty good and the fact that you work in the same place is easier to combine with family life.

You are what you eat!

[Anonymous Coward]

The old saying is slightly true. You are what you it. It is the food you eat that determines your gut bacteria, which in turn can influence your body. To what extent you may ask? More research is being done, but it hints at way more than what was previously thought.

Re:I am scientifically predicting

[Anonymous Coward]

Wakefield wasn't studying vaccines, and at the time wasn't even against vaccines when he was attacked in the media.

He's a gut specialist, and seems to know his field of study, what do you know about gut/brain connections?

If the truth is that Wakefield is vindicated because of this, then you are now the denier.

Anecdotal patient reports have once confirmed

[sichbo]

There was an interesting segment regarding shit replacement therapy in a documentary "Life on Us". One of the patients had reported an inexplicable sudden loss of a long term depression after the treatment.

More research in this area would be really great, since a correctly balanced microbiome seems to have positive impacts on a pretty wide range of maladies from obesity to cognitive defects. I've recently been wondering whether or not the only difference between the skinny guy and the fat guy, both eating more or less the same garbage with the same sedentary activity level, is simply gut bacteria/digestive efficiency.

Re:Blood-brain barrier

[HiThere]

IIUC, if you want to open the blood-brain barrier, you use ultrasound rather than microwaves.

Re:I am scientifically predicting

[HiThere]

Too late. It happened before you posted.

Re:I am scientifically predicting

[silentcoder]

I was predicting the time from the story hitting the frontpage.

That's my story and I'm sticking to it.

Asthma and gut bacteria?

[Traf-O-Data-Hater]

As a life-long asthma sufferer, I've had this odd observation. A few months ago I went to the doctor for an infected foot, which had swelled up. I was prescribed an antibiotic which I duly took.
Apart from taking care of the foot, something else totally unexpected happened to me. My mild but chronic asthma (wheezing, coughing etc) all but completely disappeared. Not just a bit, but totally. I had not changed my prescribed corticosteroid medication and reliever during this time.
I remarked to my wife I hadn't felt this good for years, my nose was clear, breathing perfectly, felt super-fit. After I finished the antibiotic the good feeling gradually tapered off, and I am back to the occasional asthma. But it was noticeable how much of a beneficial side-effect it was.