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Study shows Anxiety may be in your gut, not in your head.
August 5, 2011 11:19 AM   Subscribe

"Researchers at McMaster University have conclusive evidence that bacteria residing in the gut influence brain chemistry and behaviour. [...] To confirm that bacteria can influence behaviour, the researchers colonized germ-free mice with bacteria taken from mice with a different behavioural pattern. They found that when germ-free mice with a genetic background associated with passive behaviour were colonized with bacteria from mice with higher exploratory behaviour, they became more active and daring. Similarly, normally active mice became more passive after receiving bacteria from mice whose genetic background is associated with passive behaviour."

Abstract of the paper in Gastroenterology. Further reading: Chronic Gastrointestinal Inflammation Induces Anxiety-Like Behavior and Alters Central Nervous System Biochemistry in Mice. (PDF)
posted by stoneweaver (65 comments total) 43 users marked this as a favorite

 
So... the bacteria made me do it?
posted by likeso at 11:21 AM on August 5, 2011 [3 favorites]


You are what eats what you eat?
posted by GenjiandProust at 11:22 AM on August 5, 2011 [20 favorites]


My brain is still process this, but my gut instinct says they are on to something.
posted by fings at 11:24 AM on August 5, 2011 [16 favorites]


Oh, god - this is a fascinating study, but all I can think upon seeing it is that Andrew Wakefield's insane anti-vaccine followers are going to be all over it.

The headline might as well be "Researchers at McMaster University have conclusive evidence that bacteria residing in the gut of lab rats cause measles outbreaks in Waldorf schools."
posted by Wylla at 11:24 AM on August 5, 2011 [1 favorite]


The ancients were on to something, weren't they?
posted by tommasz at 11:26 AM on August 5, 2011 [1 favorite]


Well at least my bacteria are humanely raised...
posted by nathancaswell at 11:27 AM on August 5, 2011 [7 favorites]


I am legionella.
posted by likeso at 11:27 AM on August 5, 2011 [42 favorites]


ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh!
posted by rebent at 11:29 AM on August 5, 2011


I encourage everyone who wishes to live a drug-free life to destroy all the bacteria in their gut
posted by crayz at 11:30 AM on August 5, 2011


Psst. Hey kid, want some cool bacteria?
posted by IndigoJones at 11:30 AM on August 5, 2011


Shades of Blood Music.
posted by sourwookie at 11:32 AM on August 5, 2011 [8 favorites]


So, we can do social engineering with yogurt. Make the populace more or less aggressive as needed.
posted by stbalbach at 11:36 AM on August 5, 2011 [5 favorites]


I will take a quart of motivation-inducing yogurt, please.
posted by gregoryg at 11:38 AM on August 5, 2011 [14 favorites]


I will take a quart of motivation-inducing yogurt, please.

I need a gallon of Goldman-Sachs yogurt to pay off my student loans.
posted by Mister Fabulous at 11:40 AM on August 5, 2011 [3 favorites]


sourwookie: "Shades of Blood Music."

The later Vitals is also applicable, especially in riffing on behavior modification by body bacteria, turned up to 11.
posted by Drastic at 11:42 AM on August 5, 2011 [1 favorite]


I sterilized my gut with a lot of vodka last night and I don't feel like doing much of anything.
posted by cjorgensen at 11:42 AM on August 5, 2011 [5 favorites]


I don't get all the lulz here. This is important. With toxoplasmosis, at least the germ has to be in your brain. This is just in your gut. How many seems-to-be-hereditary-but-we-can't-find-the-gene mental disorders, for instance, are actually infections? Eradicating, say, depression or psycopathy could be a game-changer.
posted by DU at 11:43 AM on August 5, 2011 [32 favorites]


HA, I knew I was right to be eating to McDonald's all those years! You wimps were just trying to keep me down.
posted by Brandon Blatcher at 11:44 AM on August 5, 2011


Oh geez, Colbert is going to have a field day with this...
posted by JoeXIII007 at 11:47 AM on August 5, 2011


Get ready for the booming business in Nobel fecal transplants.

"for just $10000, you can put my poop up your butt"
posted by idiopath at 11:47 AM on August 5, 2011 [6 favorites]


You don't know your head from your gut.
posted by effluvia at 11:48 AM on August 5, 2011 [1 favorite]


I shit you not.
posted by Elmore at 11:49 AM on August 5, 2011


Eradicating, say, depression or psycopathy could be a game-changer

Maybe it's the moody bacteria in my gut but I think if we ever get to a total control of personality as brain chemistry then were going to get up with mandatory Loyalty and Enthusiastic Worker injections in order to be fed and housed.
posted by The Whelk at 11:49 AM on August 5, 2011 [8 favorites]


On the one hand,

Chronic Gastrointestinal Inflammation Induces Anxiety-Like Behavior and Alters Central Nervous System Biochemistry in Mice

Well, yeah. If your stomach hurt all the time, you might be anxious and depressed to the point of suicide too. Look at Kurt Cobain.

On the other hand, there are a lot more bacteria in us than there are "us" cells.
posted by infinitewindow at 11:51 AM on August 5, 2011 [1 favorite]


As if Cordyceps wasn't bad enough.
posted by Solomon at 11:54 AM on August 5, 2011 [2 favorites]


This explains my overwhelming need to consume simple sugars and emit methane.
posted by PlusDistance at 11:54 AM on August 5, 2011 [14 favorites]


Wasn't this an episode of Futurama?
posted by lizbunny at 11:54 AM on August 5, 2011 [3 favorites]


Ah come on. I keep running into news related to yoghurt today, just after I badly failed my first yoghurt making attempt, and this is making my irritable bowel a lot more irritated. Oh where are you, friendly bacteria, when I most need you?

Chronic gastrointestinal
inflammation induces anxiety-like behavior


Tsk. Scientists. I could have told you this without you having to euthanize those poor little mice.

Seriously, this is fascinating, it'd be interesting to see what they can do with experiments on humans and then practical applications. Just please don't tell me that "colonizing" one person with bacteria from the gut of another means what I think it means.
posted by bitteschoen at 11:55 AM on August 5, 2011


I think if we ever get to a total control of personality as brain chemistry then were going to get up with mandatory Loyalty and Enthusiastic Worker injections...

Just like when the Salk Vaccine enslaved us all.

Every generation thinks the Latest Scientific Advance is Playing God.
posted by DU at 11:59 AM on August 5, 2011


Something something Human Centipede?
posted by scottatdrake at 11:59 AM on August 5, 2011


bitteschoen: check my link above, it does
posted by idiopath at 12:02 PM on August 5, 2011


How many seems-to-be-hereditary-but-we-can't-find-the-gene mental disorders, for instance, are actually infections? Eradicating, say, depression or psycopathy could be a game-changer.

It has huge implications for social policy as well, specifically the link between poverty, poor diet, and crime levels. I've gotten interested in this in general terms from reading a lot about sentencing policy and wondering about the effects of prison diets, and this research seems highly relevant. I wish I knew a bit more about this to guess what impact ditery changes could have on gut fauna.
posted by anigbrowl at 12:04 PM on August 5, 2011 [6 favorites]


"Working with healthy adult mice, the researchers showed that disrupting the normal bacterial content of the gut with antibiotics produced changes in behaviour"

So could ingesting that Danone stuff with the "good bacteria" affect peoples mental states, or am I stupid/confused? (posts this with conspiracy write-up on davidicke.com. Thinking of it like that reminds me of "The Future Pharmacological Congress" by Lem. And nthing Blood Music)
posted by marienbad at 12:06 PM on August 5, 2011


"The Future Pharmacological Congress" by Lem

The Futurological Congress, but yes.
posted by anigbrowl at 12:09 PM on August 5, 2011


How many seems-to-be-hereditary-but-we-can't-find-the-gene mental disorders, for instance, are actually infections? Eradicating, say, depression or psycopathy could be a game-changer.

Remember the days before a microbe connection with stomach ulcers was established? Doctors would tell people to drink MILK to treat it for chrissakes!
posted by ZenMasterThis at 12:10 PM on August 5, 2011 [2 favorites]


I don't suppose they did anything to see if the passives had the "right" bacteria, and thus did not need to seek out new food resources, and if the actives had the "wrong" bacteria and were motivated by upset tummies to find new food resources.
posted by Ardiril at 12:15 PM on August 5, 2011 [3 favorites]


Look, I think this is a really cool study and general area of research, and I am generally sympathetic to metagenomic and microbiome research. But this is also a case where actually reading the damn article, and not just the PR gloss issued by the researchers' university, illuminates things quite a bit.

The PR gloss says: "They found that when germ-free mice with a genetic background associated with passive behaviour were colonized with bacteria from mice with higher exploratory behaviour, they became more active and daring."

Sounds amazing - gut flora make mice more active and daring! Maybe I can quaff a few bacteria before a tennis match and I'll do better! But if you go to the actual article, here's what you find:

(1) They measured behavior in two ways: a "light/dark preference test" in which the mouse was placed in an illuminated box connected with a darker box, and monitored to see how long it spent in each box and how far it traveled; and a "step-down test" in which a mouse was placed on an elevated platform in order to see how long it would take to step down.

(2) Their findings: in the treated mice, the average step-down time was reduced from 200 to 100 seconds, the average time in the light box was upped from 150 to 250 seconds, and the number of times the mice switched between boxes was upped from ~30 to ~40.

(3) About that "active" part: the study itself concludes that in the treated mice "their overall locomotor activity, assessed by total distance covered or average velocity, was not affected." So, actually, they weren't more "active."

There you have it. Taking a minute and a half less to step off a pedestal and spending more time in a light box were interpreted as more exploratory and daring, and less apprehensive.

That interpretation is fine. But there are plenty of other equally plausible ones. Maybe the new gut flora also affected the mice's vision, so they couldn't see well and thus stepped off accidentally and preferred an environment with more light. Maybe it made them nauseous, so they didn't like heights and dark places. Who knows. And this leaves aside the whole question of how much can be generalized to humans from behavioral studies in mice.
posted by googly at 12:21 PM on August 5, 2011 [25 favorites]


What a load of mousepoop.
posted by Splunge at 12:25 PM on August 5, 2011


Maybe I can quaff a few bacteria before a tennis match and I'll do better!

May I recommend something containing yeast sediment instead?
posted by ZenMasterThis at 12:27 PM on August 5, 2011


Every generation thinks the Latest Scientific Advance is Playing God

Something does something with no negative side effects is lousy fiction. There is a pattern of medical aliments being attributed to morality or behavior being overturned by for more treatable medical conditions. This is wonderful, of course, but if you take the large flying leap into fantasy extrapolation ( a place where I have built a house and garden) then the possibility of casual personality alteration makes for some more possibilities.

Also, and in mice, science news cycle, etc,
posted by The Whelk at 12:32 PM on August 5, 2011


There you have it. Taking a minute and a half less to step off a pedestal and spending more time in a light box were interpreted as more exploratory and daring, and less apprehensive.

If you read the notes, you'll find that experimental proxies like that are usually selected because of an already-established correlation.
posted by anigbrowl at 12:34 PM on August 5, 2011 [6 favorites]


And this is why I drink scotch. I'm all like, "Hey gut bacteria? You think you're going to influence me? Try doing it while you're swimming in a sea of Laphroaig Quarter Cask, you cocky little fucks."

And they respect me for it.
posted by Decani at 1:33 PM on August 5, 2011 [13 favorites]


I think the largest possibility is that the obesity epidemic is an actual epidemic. Being thin means you have gastrointestinal flora that doesn't fuck with your brain's biochemistry, and not inherent moral rectitude and stoicism.
posted by Slap*Happy at 1:33 PM on August 5, 2011 [4 favorites]


I hope someone smart and successful throws up in my mouth really soon.
posted by hanoixan at 1:37 PM on August 5, 2011 [3 favorites]


This shouldn't surprise anyone. Your second brain is your gastrointestinal system. Literally.
posted by TwelveTwo at 1:46 PM on August 5, 2011 [2 favorites]


Be careful who you french kiss.
posted by Rashomon at 1:48 PM on August 5, 2011 [1 favorite]


Laphroaig Quarter Cask

Is that the one that's always advertised in Harpers with the cartoon of the guy sitting in the chair? Cause if so, I bet your bacteria are down there wearing European Style Berets, ghostwriting memoirs while arguing about Proust.
posted by nathancaswell at 1:48 PM on August 5, 2011 [2 favorites]


I have literally no idea what you are talking about, nathan.
posted by Decani at 1:49 PM on August 5, 2011


I just spent like 15 minutes trying to google it. There is a scotch that's always advertised in Harper's with a cartoon of a guy sitting in his study with a glass and a book. The copy says something like "If there's a greater pleasure than reading the great works of Literature while sipping a glass of the Laphroaig Quarter Cask I have yet to find it." It's so pretentious it makes me laugh out loud every time I see it.

Also always advertised (in the very back) are European Berets and a memoir ghostwriting service.
posted by nathancaswell at 1:53 PM on August 5, 2011


idiopath, thanks for that link - that sounds even more amazing than this, at least in terms of the specific proven effectiveness on infections and bowel diseases, not potential effect on human behaviour. It'd be great if they did more work on it, for the whole range of bowel problems. If it's so effective on stuff like serious infections and chronic ulcerative colitis, just imagine what it could do for the more ordinary and widespread range of ailments IBD and IBS and the lot. So many people seem to be suffering from those problems today. (Probably not totally unrelated to the increasing amount of antibiotics in food we consume?)

(and yeah a bit icky but it says they 'extract' the bacteria sooo I imagine it'd be less icky than it sounds... and when you're blessed with one of the above ailments I imagine the ickiness factor would not be an issue at all)
posted by bitteschoen at 1:57 PM on August 5, 2011


If I had known I could get a McMasters I wouldn't have bothered getting an M.A.
posted by TheTingTangTong at 1:57 PM on August 5, 2011


I just hope if I get a gutload of the right bacteria I'll get all my hair back.
posted by digsrus at 2:41 PM on August 5, 2011


idiopath, thanks for that link - that sounds even more amazing than this, at least in terms of the specific proven effectiveness on infections and bowel diseases, not potential effect on human behaviour. It'd be great if they did more work on it, for the whole range of bowel problems. If it's so effective on stuff like serious infections and chronic ulcerative colitis, just imagine what it could do for the more ordinary and widespread range of ailments IBD and IBS and the lot. So many people seem to be suffering from those problems today. (Probably not totally unrelated to the increasing amount of antibiotics in food we consume?)

Several studies and reviews suggest that IBS, IBD, and certain forms of auto-immune arthritis may be triggered or exacerbated by diet in some patients, and that diet change (in particular, low-carb and/or low-dairy diets) can work as a primary or adjunct treatment. Many patients report that stress is also a major trigger... and as any owner of a stomach knows, stress causes changes in gut flora. This seeming connection between bacteria in the gut and auto-immune disorders is really interesting... who knows, maybe many otherwise-unexplained disorders have their origins in what we (or our friendly neighborhood bacteria) eat.
posted by vorfeed at 3:13 PM on August 5, 2011


Next, we'll find that we're nothing more than giant virtual bodies for a strain of bacteria that wanted to rule the world.
posted by mantecol at 4:02 PM on August 5, 2011 [1 favorite]


(I originally meant it as a joke, but I think that was the most profound thought I've ever had.)
posted by mantecol at 4:16 PM on August 5, 2011 [2 favorites]


Presumably they'll fight it out with the memes for dominance.

Talk about levels of abstraction.
posted by titus-g at 4:28 PM on August 5, 2011


How many seems-to-be-hereditary-but-we-can't-find-the-gene mental disorders, for instance, are actually infections?

Heritability is typically shown with MZ/DZ twin studies, which should not be affected by shared microbe exposure. Sorry.
posted by a robot made out of meat at 4:53 PM on August 5, 2011


As usual, the important thing with studies of this sort is not to wait until further studies confirm or falsify the conclusions, but to INVEST MONEY NOW!!!!
posted by happyroach at 4:58 PM on August 5, 2011


There you have it. Taking a minute and a half less to step off a pedestal and spending more time in a light box were interpreted as more exploratory and daring, and less apprehensive.

This is pretty well validated as mouse anxiety. It has a genetic basis in gabba-a receptors and responds to anti-anxiety drugs. Mouse behavior people wouldn't claim 1-1 correspondance, but that this happens at all is very suggestive.
posted by a robot made out of meat at 5:47 PM on August 5, 2011 [4 favorites]


This is interesting, but mice are not people.
Who's willing to volunteer for human trials?
posted by wheloc at 9:11 PM on August 5, 2011


It has a genetic basis in gabba-a receptors ...

The discovery of which, if I recall correctly, won Dr. Joey Ramone the Nobel Prize in medicine.
posted by ZenMasterThis at 9:26 AM on August 6, 2011 [2 favorites]


Forgive the ipad induced spelling errors.
posted by a robot made out of meat at 10:56 AM on August 6, 2011


If you read the notes, you'll find that experimental proxies like that are usually selected because of an already-established correlation.

Good luck, I'm behind seven experimental proxies.
posted by davejay at 11:14 AM on August 6, 2011


MetaFilter: pretty well validated as mouse anxiety.
posted by Crabby Appleton at 6:02 PM on August 7, 2011



Gut flora is maintained through many processes and "transfering" gut bacteria will not necessarily work if the gut environment can not sustain the right balance of gut bacteria. Our bodies have regulatory processes that manage this and exercise seems to have an affect (among many things)

"The variation among different species or even among different strains within a species reflects the complexity of the genetic polymorphism which regulates the immune system functions. Additionally factors such as, gender, particular habits, smoking, alcohol consumption, diet, religion, age, gender, precedent infections and vaccinations must be involved. Hormonal profile and stress seems to be associated to the integrity microbiota and inducing immune system alterations"
http://www.ncbi.nlm.nih.gov/pubmed/21515397

The proposal that infection may have a valid role in the progression of mental illness/mood disorders/behavioral problems is perfectly legitimate and being researched. While we have found toxoplasma and influenza problematic prenatally-- what about cold sores(herpes?) what about athletes foot? Candida? Infections can most definately affect gene expression and numerous biological processes far after the infection is gone. But I think a critical factor in immunology is that we are continually finding that chronic stress/poor diet/types of daily activities/social isolation/abuse/trauma/ETC are all very big factors in the development of a healthy immune system. We tend to get excited if we find ONE biological factor that affects mood or behavior and pressume the solution is to manipulate the genes or that ONE biological factor when the body is a system of processes all regulating each other and we are missing the bigger picture of how to discern the extent of what is out of whack and how to ensure all of those factors are addressed as best we are able.


"Infection with a number of viruses during pregnancy including influenza, and rubella are known to increase the risk of schizophrenia in the offspring (Brown, 2006). Animal models using influenza virus or Poly I:C, a viral mimic, have been able to replicate many of the brain morphological, genetic, and behavioral deficits of schizophrenia (Meyer et al., 2006, 2008a, 2009; Bitanihirwe et al., 2010; Meyer and Feldon, 2010; Short et al., 2010). Using a murine model of prenatal viral infection, our laboratory has shown that viral infection on embryonic days 9, 16, and 18 leads to abnormal expression of brain genes and brain structural abnormalities in the exposed offspring (Fatemi et al., 2005, 2008a,b, 2009a,b). The purpose of the current study was to examine gene expression and morphological changes in the placenta, hippocampus, and prefrontal cortex as a result of viral infection on embryonic day 7 of pregnancy." "Our results demonstrate that prenatal viral infection disrupts structure and gene expression of the placenta, hippocampus, and prefrontal cortex potentially explaining deleterious effects in the exposed offspring without evidence for presence of viral RNAs in the target tissues."

http://www.ncbi.nlm.nih.gov/pubmed/21277874
posted by xarnop at 7:42 PM on August 7, 2011 [1 favorite]


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