Gut Bacteria Affect the Brain

Rambo Tribble writes "John Cryan, a researcher at the University College Cork, explains the relationship between the bacteria in your gut and your brain. 'In a pioneering study, a Japanese research team showed that mice raised without any gut bacteria had an exaggerated physical response to stress, releasing more hormone than mice that had a full complement of bacteria. However, this effect could be reduced in bacteria-free mice by repopulating their gut with Bifidobacterium infantis, one of the major symbiotic bacteria found in the gut. Cryan’s team built on this finding, showing that this effect could be reproduced even in healthy mice.' It seems the flora in your intestines can influence brain development as well as aspects of health and nutrition, which in turn affect such things as hormones and neurotransmitters. 'His team tested the effects of two strains of bacteria, finding that one improved cognition in mice. His team is now embarking on human trials, to see if healthy volunteers can have their cognitive abilities enhanced or modulated by tweaking the gut microbiome.'"

Comments

We are a colony organism

[RichMan]

We are 90% bacteria. It is time we stopped viewing ourselves as a monlithic organism and started viewing ourselves as some sort of managed colony.
http://www.npr.org/templates/s...

"We think that there are 10 times more microbial cells on and in our bodies than there are human cells. That means that we're 90 percent microbial and 10 percent human. There's also an estimated 100 times more microbial genes than the genes in our human genome. So we're really a compendium [and] an amalgamation of human and microbial parts."

Re:We are a colony organism

[SuricouRaven]

We're more of a bacterial mass-transport vehicle.

Re:We are a colony organism

[i kan reed]

This is misleading, because our mass is still predominantly genetically human eukaryotic cells. Bacteria are so tiny that there are a greater number of them, but we're still mostly just human.

Re:We are a colony organism

[DoofusOfDeath]

Well, crap. I was taking an antibiotic this week. But not it's starting to sound like genocide.

Re:We are a colony organism

[danlip]

Just suicide. Many other instances of those bacteria strains inhabit other people, so you won't be committing genocide (unless you use a blessed scroll).

Re:We are a colony organism

[Samantha Wright]

As someone who does this stuff for a living, I'd argue the contrary—that the weight ratio is misleading, because it's an exception. In terms of RNA and protein-coding genes, isoforms, homologues, and selection rates, in addition to more obvious things like number of cells, they vastly outstrip the core of the body. Think also of how much more time they've cumulatively had to evolve and swap genes!

The best analogy for this, I think, is a *nix distro—the human genome is a monolithic kernel, and the bacteria are all the shell scripts and daemons that help manage it.

Re:We are a colony organism

[ColdWetDog]

I always knew humans were basically full of shit.

Re:We are a colony organism

[ColdWetDog]

The best analogy for this, I think, is a *nix distro—the human genome is a monolithic kernel, and the bacteria are all the shell scripts and daemons that help manage it.

It's funnier if you run it the other way.

Re:We are a colony organism

[cold fjord]

...the human genome is a monolithic kernel, and the bacteria are all the shell scripts and daemons that help manage it.

So what you're telling me is essentially that the viability of myself and any offspring is going to depend on a massive collection of perl scripts. Lovely. I'm forked. :(

Re:We are a colony organism

[rmdingler]

Careful with that antibacterial slant to your comments...

it turns out bacteria are people, too.

Re:We are a colony organism

[pgpalmer]

So Soylent Green is... bacteria?
Ew.

Re:We are a colony organism

[rmdingler]

My gut tells me you're onto something here.

Re:We are a colony organism

[cold fjord]

Maybe not genocide, but at least germicide.

Don't worry, you can backfill the little buggers.

Machines

[i kan reed]

I don't think I mind being an extraordinary complex machine functioning to protect the interests of very simple organisms incapable of thinking for themselves. But that might just be my bacterial overlords talking.

Re:Machines

[i kan reed]

Maybe we accept politicians because we're so used to taking orders from primitive, self-interested organisms.

Morality questions

[DoofusOfDeath]

I know I'm not the first person to think of this, but...

The more external influences we see on brain function, the less sure I am of how appropriate it is to hold people responsible for their actions.

For example, if child molestation is something one is predisposed to after being molested as a child, what's a just punishment if/when that person him/herself goes on to molest? Or, in this case, if ones gut bacteria makes on prone to certain behaviors, for example stress --> violence (not sure that's right, but just for the sake of discussion), should we hold every to persons equally accountable for having a violent reaction?

Re:Morality questions

[danlip]

Independent of this, there is a moral question of "should we be punishing people?" The alternative is to focus on deterrence, rehabilitation, and protecting society. "Protecting society" could justify locking someone away for ever (if the justice system determines there is no chance of rehabilitation). "Rehabilitation" could include altering their microbiome if we figure out how, or it could just be psychological work. Punishment is government administered revenge - it may provide some deterrence, but it's not particularly good at it. But modern justice systems still focus almost entirely on punishment.

Re:Morality questions

[cellocgw]

Yeah, well, misusing the word "exceptional" doesn't change the facts of your children's medical condition(s).
And you should take a step back and consider just how incredibly selfish you sound when you claim you wouldn't give them a cure for their physical/mental defects. Did you ever stop to think how much fuller their lives would be if they could function somewhere in the normal range? Or to think what *they* would say if offered the chance?
Maybe you should read "The Reason I Jump" for some preliminary insight into just how difficult life actually is for the impaired.

Re:Morality questions

[JoeMerchant]

For a couple of decades, the majority of my peers called me alternately "Moron," "Idiot," "WTF is wrong with you," etc. I didn't like them doing that, but I really wouldn't have liked being made into a carbon copy of them. I was fortunate enough to be "in sync" with the academic testing regime of the day, so while most of my classmates called me "Moron," I was consistently turning in test scores that said otherwise, in spades.

My kids aren't getting the test scores that I did, but they are having a less traumatic time in school - no bones broken by childish pranks, nobody twice their weight sitting on them to pin them down in a fire ant pile, and as parents, I think we are much more aware of what's going on with our kids in school than my parents ever were. Their school experience could be better than it is, if we had unlimited resources, given what we've got, they're doing o.k.

Be careful when you think about "normal" and "fuller life" - my high school graduating class had about 250 people (at the beginning of senior year, closer to 200 by graduation), "normal" would be the middle of that group of 250, the ones that knocked around town attending Junior College after high school, getting crap jobs because they got their girlfriend pregnant, joining the military, spending a disproportionate amount of their time smoking grass, etc. The top 10-15% who took the advanced classes and went on to mostly get university degrees and good jobs, they're not normal, they are also exceptional.

Also be careful about wishing for a world where everyone suddenly becomes like the "top 5%" model students of today, learning all the course material presented to them, working diligently, etc. That would be a very different world from the one we live in, surely better in some ways, but shockingly worse in others.

Re:Morality questions

[JoeMerchant]

Well, the way my kids "behave," you'd think they could do better on those tests, "if they just applied themselves." "They're obviously really smart, they just don't talk like other kids their age do.." etc. There's a reason it's called a dis-ability, but, from a parent's ever optimistic perspective, they're "differently-abled" and I hope I can help them find a way to be themselves and also not get clobbered by the competitive world out there.

Re:Morality questions

[JoeMerchant]

Well, depending on who is administering justice, my kids may well end up incarcerated some day. They're not violent, or harmful to others, or mean, or prone to unusual destruction of property or theft, but they don't follow verbal directions well, at all. Judging from all the Cops episodes ever produced, failing to follow the officer's direction, immediately, invariably leads to arrest... We've also been through a whole host of elementary schools, with principals that ranged from apathetic, to incompetent, to outright vicious and retaliatory, to compassionate and very helpful. The vicious one, among other things, sent the county officials to our home to "inspect" the home living conditions, in direct retaliation for us standing our ground about not being locked up in the rubber room all day long. The county official became our good friend to the point that she was no longer called in to any consultation meetings because the county people didn't want us having her on our side in the meetings...

If such a "magic pill" existed, and the kids expressed a desire for it, I would give it to them if I thought they understood what it would do. We already have used pro-biotics and similar treatments, not in hopes of "curing" or "changing" them, but in hopes of helping them to feel and function better. Success has been limited, but not non-existent.

Re:Morality questions

[gzuckier]

Interesting to ask people whether, if we could guarantee a person would never commit a crime again, they would still need to be punished. Lots of people say yes, but have trouble explaining why. They're too embarrassed to say they like the idea of revenge.
On another note, C. S. Lewis points out in "That Hideous Strength", that when we set up punishment for crimes, the length of the sentence is specified; but if you repudiate this as primitive and barbaric and bring about new modern methods of rehabilitation, then you can keep the guy forever if he doesn't demonstrate proper rehabilitation.

Meat Tubes

[resistant]

I'm not surprised by this discovery. Evolutionarily, we're all really complex support systems for long meat tubes that ingest energy and building materials and excrete whatever is not useful. Even the mighty brain only exists to increase the odds of the tube surviving. Bacterial strains that also increase the chances of a meat tube surviving will be favored by simple Darwinian logic. Naturally, they will influence every body system, including the brain.

Admittedly, one doesn't like to feel like a puppet. I wonder what this means for the free will that humans supposedly possess.

Re:Meat Tubes

[jeffmflanagan]

> I wonder what this means for the free will that humans supposedly possess.

Nothing, because free will isn't really a meaningful concept. It all falls apart when you try to define it. You either wind up with a meaningless definition, or no free will. It appears that we respond to stimulus in the only way we can based on our biology and past experiences. Free will became extremely unlikely when we realized that souls are imaginary.

Re:Meat Tubes

[easyTree]

Nothing, because free will isn't really a meaningful concept. It all falls apart when you try to define it.

When definition proves difficult, often a series of examples allows the definition to be communicated indirectly.

I'll start the ball rolling by responding only with the word 'cheese' as a full explanation of your incorrectness.

Re:Meat Tubes

[Immerman]

> Free will became extremely unlikely when we realized that souls are imaginary.
Really, when did they prove this?
Free will first became completely impossible when we discovered that everything in the universe operated according to deterministic physical laws.
Then it became probably illusory when we discovered that quantum mechanics was non-deterministic and had an influence on brain function.

I'm not overly inclined to believe in an personal immortal soul (which is an extremely narrow subset), but I can't think of any way you could prove that some meta-physical influence doesn't "stack the dice" of the quantum phenomena that influence brain function. Even if you could prove that there were no statistical anomalies present all that does is set limits on the kinds of influences possible - after all rolling 2,3,5 is statistically equivalent to rolling 5,2,3, but can make a huge difference on the outcome of the game.

I should have listened to my mother

[Ukab the Great]

When she told me that donuts would make me stupid.

Healthy bacterias

[gmuslera]

Be careful with what makes you what you are. This shows the importance of not abusing generic/strong antibiotics, breast feeding childs for years (probiotics are probably an incomplete fix) and not removing your appendix without need. If you don't care enough about that, may be a fecal transplant in your future.

Re:Healthy bacterias

[HairyNevus]

"Another method of adjusting the bacterial profile of your gut is to undergo a transplant that involves taking faecal material from a donor’s intestine – often a close relative – and implanting into a recipient via enema infusion. This unorthodox treatment has been shown to successfully treat infections caused by pathogenic bacteria colonising the gut."

Shit transplants....we've gone too far.

Maybe they were just feeling sick?

[Marrow]

When my gut is in an uproar, I don't have patience for mazes and puzzles either. Maybe they were just feeling sick. Add stress, and the feeling magnifies.

Re:Stating the obvious

[TapeCutter]

Thing is your gut has its own nervous system, the connections to the brain can be cut and the gut will still function normally.

Re:We are a colony organism &

[rmdingler]

Just noticed your sig.

I have to believe we will rectify the Beta to leave the legendary /. give and take commentary alive.

But my friend, I have lurked on the alternatives to the green line site, and it is the antithesis of pretty. Assuming your curious nature is spawned from the intellectual, root hard for a better Beta.

Re:TFA not available in UK

[easyTree]

Duh! You need to be one of the overseas viewers who don't pay anything at all for the service. Greedy Brit :P

Re:Imagine the Uproar...

[ToddInSF]

Imagine if there were a hetrosexual bacteria, and scientists developed and antibiotic for it !