The gut microbiome helps social skills develop in the brain in fish | Hacker News Reader

The gut microbiome helps social skills develop in the brain in fish

quantamagazine.org

It's pretty hard to untie the multiple connections and ascribe specificity to brain development and lack of a decent gut microbiome.

For example, we know pretty well that humans subjected to famine/malnutrition/toxin exposure/etc. in the first two years of life, when ~70% of brain development takes place, will tend to have decreased cognitive function over their lifetime.

If being deprived of a microbiome reduces the ability of the gut to absorb nutrients, then essentially a kind of starvation could take place which reduces brain development, and as healthy brain development seems to be one of the requirements for normal social interactions with others, it could just be nutrient starvation rather than any direct neurochemical signaling from gut microbes to neurons that's messing up brain development.

There have been some experiments on megadosing probiotics to help with social anxiety disorder (SAD). There is at least this one guy who says it fixed it completely. He makes a megadose by growing specific probiotics in milk.[0]

This is different however, because the article talks about early brain development and autism spectrum disorder (ASD). Maybe early microbiome disruption -> ASD, later -> SAD?

[0] https://pdfcoffee.com/experimental-treatment-for-social-phob...

> social anxiety disorder (SAD)

I thought it was generally agreed that SAD refers to seasonal affective disorder?

Counterpoint: Scandinavian countries has had fermented dairy as a core part of our diet for centuries, and we are frigid AF until we get a pint in us.

Would really like to see him subject himself to an RCT of it, though - he could have someone else mix some strong flavor into the beverage to mask the taste difference from a placebo.

I recall there's a thing where those that undergo major gut surgery, which would disturb the gut biome, have a much higher chance of falling into substance use disorders afterwards.

Though a lot of gut surgery would be for bariatric weight loss, so there could be many other drivers for that correlation.

I’ve wondered whether a colonoscopy (prep for which which completely empties the gut through the use of heavy laxatives) could strongly affect your gut biome.

You could look at appendectomies, seen more often in younger people for no apparent cause.

Granted, these days the surgery is much less invasive.

Yep, also various surgeries for stomach and esophageal cancers, etc.

Gut microbiome is linked to autism. Eating probiotic l.reuterinmay may help. L.reuteri does this by upregulating host oxytocin levels which rewards social behavior.

https://pubmed.ncbi.nlm.nih.gov/27825953/

I thought that relationship was no longer believed. It's just that autistic people may eat differently causing gut biome to be different. (Sorry I don't have time to source it.)

If this is the case, would we expect to see lingering side effects in adults who were afflicted by gut issues like Crohns disease in their youths?

Wild speculation: perhaps particular foods and the gut microbiota they promote influence social structures. Perhaps one could ensure the spread of these feelings via ritual distribution of carefully prepared samples of some food... bread, say.

What happens when the magic starter culture is lost and the ritual no longer has the effect it used to?

Hypothesis: Unhealthy gut microbiome > frequent smelly farts > people avoid you > don't develop social skills.

Some of my most amazing, room-clearing farts have been directly associated with healthy eating.

Yes I’m curious if there is any correlation between smell and gut micro biome populations.

What is the best scientific article linking brain health to gut health in humans?

...in fish.

Which is fascinating! And we know that gut micro biome has impacts on humans too.

But, we shouldn't extrapolate from research in fish all the way to humans until we can show it. The painful (or joyful) thing about science is dealing with the uncertainty and knowing that hypotheses are just that.

Ok, we've infished the title. Thanks!

(This was my first infishing but it was easy because of related practice: https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...)

This was my first infishing

Lies!

https://web.archive.org/web/20221029231109/https://news.ycom...

https://news.ycombinator.com/item?id=33388837

Crap.

Or is it Carp?

It's 'carpe diem', Latin for 'infish the day'

The fact this was in fish doesn't mean we can't use this as the start of a model in humans. While it isn't a 1:1 correlation, zebrafish make good model organisms in part due to their genetic similarities to humans.

There's obviously flaws with model organisms, as the saying goes "mice lie and monkeys exaggerate" but zebrafish are surprisingly good organisms to study human problems.

If you wanna kill 20 minutes: https://en.wikipedia.org/wiki/Zebrafish#Scientific_research

This headline should be corrected to say that. Disappointed in Quanta for resorting to clickbait. It’s cool research even if it’s just fish!

Conclusions shouldn't be formed in either direction, but speculation and experimentation can be useful.

I don't think this is a problem with any of the "inmice" articles, and they are indeed very interesting to read! The only issue is that they forget to mention this small, but important detail in the title.

ah, I hear what you're saying. So I need to feed my fish probiotics so they will have the social skills to interact with my house guests better.

don't developing fetuses (feti ? fetus with long u?) of mammals go through a fish shaped stage?

if so, does that mean what applies to fish likely applies at some stage in or some way?

My guess is that you are referring to the "ontogeny recapitulates phylogeny" theory:

https://en.wikipedia.org/wiki/Recapitulation_theory

Which, despite the awesome rhyming phrase, doesn't really represent reality much. But even if it did, feral stage development wouldn't be reason to believe that this applies to humans.

The better reason to believe there's a chance this applies to humans, to some degree, is that humans and fish share similar brain signaling and micro biome products; which may be true or may not be! It's a big hint of a direction to look, which is great.

But even if this doesn't apply to humans, it's valuable research because it defines what's possible in biology.

( autocorrect typo above : fetal was converted to feral )

When are we going to accept that we are just a life support system for a bacterial colony?

Also trees are just farming us to create the CO2 that they crave. It's dangerous to look at the world with a human-first lens.

Also dogs at some point decided they'd stop looking for food themselves and instead focus on taking advantage of how insanely industrious humans are

And wheat domesticated us, not the other way around.

Botany of Desire by Michael Pollan is a great book / documentary that explores this view.

And cows, so they could greatly increase their numbers and outcompete other herbivores.

Given that there are organisms that can literally effect human and animal behavior, in a way the system itself is partly controlled by the organisms inside it.

The big ones are toxoplasma, rabies, etc but there's a theory that many viruses and bacteria seek to control the behaviour of the host to enable successful spread. Perhaps flu makes people more social before they get too ill? Perhaps some sexually transmitted diseases change behaviour to make the host more promiscuous? Almost impossible to perform any studies on humans, but for fish...

This sounds like the premise for a good zombie movie.

Aliens movies are similar!

I guess skynet is just another "Johnny come lately", late to the party and not biologically diverse enough to be original :)

Funniest comment tree I've read all day. Faith in humanity restored from a floppy :p

Or, for the really old folks - "...restored from a paper tapeworm. :p"

If you listen closely, you can hear an ameoba laugh.

If the ameobas didn't have the guts to fix all the worlds problems, what chance does that leave boffins? Tri low bite as they might :p

I mean, if you dig a bit deeper you'll find all life is just elaborate Rube Goldberg machines comprised of chemical interactions.

We are a system with them, instead.

Then why didn't they stop up from developing antibiotics?

Because there are different types of bacteria that are vying for domination. The "good" bacteria are fine with antibiotics because they usually only get used when there are too many "harmful" bacteria that threaten the life support system.

Have to sacrifice some of the colony so the host doesn't die. Previously they would have been wiped out by the invading bacteria army anyway

The bacteria developed antibiotics! We just took them from the bacteria.

Wasn't it mostly fungi where humans found antibiotics?

Penicillin did, but I think a lot of the newer ones were derived from bacteria. But doing a quick web search right now I'm mostly getting potential new antibiotics that came from bacteria, rather than proven antibiotics, so now I'm wondering about the actual bacterial contribution...

Some say it's a symbiosis

So wine and dine?

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