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Can the Bacteria in Your Gut Explain Your Mood?

nytimes.com

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Re: Can the Bacteria in Your Gut Explain Your Mood?

#11

Post by peterfirefly »

blfr wrote: post #4
DanBC wrote: post #3

Earlier quoted context omitted.

It doesn't sound like a plausible mechanism when you first hear it, and so it doesn't get much research. It's not that long ago that we found gut flora that helps cause some obesity; and other gut flora that helps cause normal weight.

My point is that you wouldn't need research if the effect was large. If depressed people stopped acting depressed after having a minor infection (treated with antibiotics), they would notice. Their families would notice. Just like people figured out that quarantine works long before we had the germ theory, and without knowing any statistics.

There are many kinds of antibiotics and many kinds of bacteria...

Re: Can the Bacteria in Your Gut Explain Your Mood?

#13

Post by vanderZwan »

blfr wrote: post #6
vanderZwan wrote: post #5

Earlier quoted context omitted.

> Yet I haven't seen any life-changing results. Not trying to be a smartass, but "not seeing something" is not really a convincing argument if you have never looked for it before. Especially here, given that there is no obvious feedback loop to give us hints at the relation between the gut flora and our mood. (are you aware of changes in your digestive chemistry and gut flora? How would you connect that to emotional…

It's presented as a dismissive question with no answer. But with the number and amount of antibiotics prescribed, wouldn't you expect a lot of curious, seemingly miraculous changes by accident? You know when you take antibiotics. You have a clear time frame, and the event is unusual enough that it should stand out.

Except that for a cause-effect relationship, you need a kind of "all else being equal" scenario. But since we take antibiotics when we are ill, we already are in an unusual state of the body. So any mood swings, if noticed at all, are just as likely (and given that we tend look among the familiar things first, I'd say more likely) to be attributed to things like poor sleep or other side-effects of whatever disease caused you to take antibiotics.

Re: Can the Bacteria in Your Gut Explain Your Mood?

#15

Post by blfr »

vanderZwan wrote: post #13
blfr wrote: post #6

Earlier quoted context omitted.

It's presented as a dismissive question with no answer. But with the number and amount of antibiotics prescribed, wouldn't you expect a lot of curious, seemingly miraculous changes by accident? You know when you take antibiotics. You have a clear time frame, and the event is unusual enough that it should stand out.

Except that for a cause-effect relationship, you need a kind of "all else being equal" scenario. But since we take antibiotics when we are ill, we already are in an unusual state of the body. So any mood swings, if noticed at all, are just as likely (and given that we tend look among the familiar things first, I'd say more likely) to be attributed to things like poor sleep or other side-effects of whatever disease ca…

There should be a lasting effect when you replace your gut bacteria, not just some mood swings.

Re: Can the Bacteria in Your Gut Explain Your Mood?

#17

Post by neuro_imager »

blfr wrote: post #2

If this effect was large, wouldn't we have spotted it by now? Doctors prescribe antibiotics for nearly anything nowadays. Along the antibiotic, you will get some sort of probiotic (selected strains of bacteria), not to mention all the yogurt and similar products we're eating. Millions of people around the world do it every year. At least some will correctly follow instructions, finish the round of antibiotic, and tak…

The effects, if present, are likely to be nuanced.

It seams likely that these sorts of effects are likely to arise from certain bacteria, and their interaction with other bacteria (as well as presumably a multitude of other factors, such as the integrity of your intestinal mucosa).

Antibiotics (particularly broad spectrum antibiotics) kill entire classes of bacteria (eg. gram positive bacteria - which would include several hundred or thousands of bacteria) and are not good at targeting a specific bacterium.

One consequence of this is the overgrowth of the remaining bacteria (eg. C. difficile which causes pseudomembranous colitis).

So the "massive natural experiment" you describe is not a very reliable one. It may be that when you take a certain antibiotic you kill off all the positive psychobiotic bacteria and the compounds they produce (or maybe just some of them) along with detrimental bacteria (or just one or the other).

You also have to factor in that there are innumerable classes and types of antibiotic, innumerable bacteria (each with their own resistance profile) and variable effects on individuals.

Re: Can the Bacteria in Your Gut Explain Your Mood?

#19

Post by shabble »

Another thing I've been pondering occasionally is what this and other discoveries might mean if cryonic neuropreservation (head/brain only) storage & reversal is ever practical, or if full head transplants become a viable surgery.

Just how much of actual personness is stored in places other than just the brain? Surely the hormonal (endocrine?) systems of the body, as well as things like the microbiome are going to play important roles, although I have no clue if they're necessary.

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