Hacker News

Habitual coffee intake shapes the microbiome, modifies physiology and cognition

110 points by scubakid 4 hours ago | 43 comments

Funded by the Institute for Scientific Information on Coffee (ISIC) — an industry body — which is a notable conflict of interest the authors disclose but don't extensively discuss

rapidaneurism 2 hours ago

It does not sound like an outcome that big coffee paid for it to be so:

Behaviourally, coffee drinkers exhibited greater impulsivity and emotional reactivity, whereas non-coffee drinkers demonstrated better memory performance.

iammjm 13 minutes ago

Do they though? Any data on that? Also, the highly caffeinated people might also be sleep deprived, which impacts memory and emotional regulation

selcuka 28 minutes ago

> It does not sound like an outcome that big coffee paid for it to be so:

Who said anything about big coffee? These guys might be a secret, anti-coffee organisation. /s

carabiner 46 minutes ago

Every damn time, for chocolate, coffee, and red wine "studies."

TazeTSchnitzel 41 minutes ago

After habitually consuming caffeine (not in coffee form) daily, usually multiple times a day, for more than a decade, a horrible mental health incident happened to me that forced me to stop it for a while. Afterwards I didn't resume the habit, and so I no longer have a tolerance.

This has let me evaluate what caffeine does with fresh eyes, so to say, because I can now consume it occasionally while having many non-caffeinated days to compare to. It's a profoundly psychoactive substance and does a lot of things to cognition. I guess I have decided I don't enjoy how it feels, having previously been dependent on it.

readthenotes1 37 minutes ago

Notably, the article is looking at coffee, both caffeinated and decaffeinated. There is a lot more to coffee than just caffeine...

rimliu 7 minutes ago

How do you know that caffeine was the cause?

ivan_gammel 2 minutes ago

This of course cannot be generalized, but withdrawal is quite noticeable for personal well-being in a positive way.

pinkmuffinere 3 hours ago

I’m super interested in this sort of study! However, it looks like n=62 here, which I think weakens the results —they’re probably just useful as suggestions of possible effects. Also, any food is expected to have similar effects on the microbiome. They didn’t test caffeine in isolation. In some ways that’s better (I don’t consume caffeine in isolation), but in some ways that’s less useful (it’s possible you get similar results from many random vegetables)

sixtyj 2 hours ago

In 1995, NASA did spiders experiment. Caffeine is a siginificant impulsivity trigger. :)

https://rarehistoricalphotos.com/nasa-spiders-drugs-experime...

jayd16 2 hours ago

Nice web, Mr. Crack spider.

bhaney 2 hours ago

> They didn’t test caffeine in isolation

But they did test both caffeinated and uncaffeinated coffee, and found the same effects in both, indicating that the effect is caused by something in coffee other than the caffeine

krige 2 hours ago

Doesn't decaf also contain caffeine, just a lot less of it?

anon84873628 2 hours ago

Typical extraction yield is 18-20%. For a 20g dose that's 4g of material consumed, or about 30 individual beans.

I wonder if you could find similar effects with 4g or broccoli sprouts, or garlic, or ginger, or cumin seed, shiitake mushroom, seaweed, soursop leaf, or...

satvikpendem 3 hours ago

What's cool is this effect exists even in decaf coffee, as someone who primarily drinks decaf black, for flavor and for a good night's rest as I'm sensitive to caffeine.

Kelteseth 60 minutes ago

What kind of decaf coffee do you drink? There are differences between the cheap chemical Methylene way to create decaf coffee and the expensive co2 way to get rid of the caffeine.

https://cleanlabelproject.org/wp-content/uploads/CLP-Decaf-C...

Schlagbohrer 3 minutes ago

Is that methylene way even legal? It basically uses petroleum fuel in the process right? I assume it was outlawed a long time ago but that might be extreme naievete for US regulatory capability...

satvikpendem 51 minutes ago

I don't buy the methylene processed ones, generally it's Swiss water processed or like you said the CO2 processed ones.

wjnc 3 hours ago

I have not much followed the science of gut microbiome and psychology. Is this really going where this article is pointing? That we can tease out causation in foods and habits via gut microbiome towards behavior and psychology? Pretty rad.

chneu 2 hours ago

There's a decent amount of research going into the hormones that our GI biome produce and how it affects us. Our body has a few different biomes and they all seem to play somewhat important roles.

colechristensen 3 hours ago

Yeah there's nontrivial evidence that among other things, the complex community living inside you manipulates your brain.

ButlerianJihad 3 hours ago

My psychiatrists agree that “hallucination” (in lay terms: “hearing voices” or “seeing things”) only refers to things that aren’t real.

getnormality 3 hours ago

Coffee modifies physiology and cognition? You're telling me this for the first time.

alecco 2 hours ago

The paper is about previously unknown ways coffee affects the body.

ButlerianJihad 3 hours ago

I was so surprised at this headline that I nearly leapt out of my chair!

jonplackett 2 hours ago

But it says it’s the same for decaf. That is more interesting

triage8004 3 hours ago

Humans known since 45 minutes after first drink

reedf1 3 hours ago

At least subjectively, coffee seems to help my memory. But maybe that's why I started drinking coffee?

I would probably drop coffee it was proven to have negative effects on memory.

bboozzoo 3 hours ago

> But maybe that's why I started drinking coffee?

you don't remember why, do you?

poly2it 3 hours ago

> ... reintroduction triggered acute microbiome changes independent of caffeine.

This sounds interesting. I've never really considered the constituents of coffee other than caffeine and what unique effects they may bring.

I wonder if I would experience behavioral effects if I replaced my coffee intake with caffeinated non-coffee drinks or pills?

kulahan 3 hours ago

Studies seem to indicate that coffee is at least as healthy, if not healthier than tea, and I have not heard this about caffeine specifically (aka the same effects coming from pills or energy drinks).

One fun fact: we still haven’t figured out why coffee makes us poop. We’ve studied every chemical in there and can’t seem to find a link, but the association is uh… well-known.

neya 3 hours ago

The only good thing that keeps me from collapsing into a state of limbo is coffee and now, even that's bad (seems more like a mixed bag, but still)? Sigh.

cyberpunk 2 hours ago

Maybe I have some neurological issue or something but whenever I quit coffee I find it extremely difficult to maintain any kind of motivation to sit in an open plan office and code. Coffee makes me a worker bee, I can understand why employers give it away for free.

So, the coffee stays for now.

neya 45 minutes ago

Yeah, exactly. I can totally relate to this. I have actually monitored my productivity on an excel sheet and the days with coffee win by a large margin. I am not sure if it's withdrawal symptoms on the days without, though.

bee_rider 3 hours ago

There have been positive and negative reports for a long long time. If coffee was going to kill us, I’d certainly have died in school!

kulahan 3 hours ago

Coffee in general is unreasonably healthy as a beverage. The overwhelming majority of science agrees it’s a quality health drink.

anon84873628 2 hours ago

Don't fret. You're allowed to enjoy things that aren't part of the scientific reductionist longevity influencer lifestyle fad :)

antonvs 2 hours ago

Nitpick: What you’re referring to is not scientific.

6LLvveMx2koXfwn 3 hours ago

"These findings reveal previously unrecognised effects of coffee on the microbiota–gut–brain axis, suggesting that microbiome profiles could potentially predict coffee consumption patterns", or, perhaps, just ask the patient?

raincole 3 hours ago

Could you elaborate on how to interpret your comment without it leading to anti-intellectualism?

6LLvveMx2koXfwn 3 hours ago

It was a joke

colechristensen 3 hours ago

You are missing the point.

If you can predict someone's coffee intake based on testing of their microbiome then you've proven that coffee intake has predictable effects on the microbiome.

The important part isn't predicting coffee use, it's just the proof that there's you can predict and perhaps control in the opposite direction leading to more research.