Art 12 ↔ Art 19 — Reader privacy protection (Article 12) through consent-based analytics conflicts with free information access (Article 19) when behavioral tracking enables personalized information filtering without explicit consent mechanisms visible to readers.

maxall4 2026-03-12 17:52 UTC link

I smell bad data. This sounds too good to be true and most studies of this kind have turned out to be false a few years down the line.

Edit: one of many examples: https://www.science.org/content/article/journal-retracts-inf...

inanutshellus 2026-03-12 18:07 UTC link

Everyone's "poo-pooing" the article because the title doesn't mention mice, but, FWIW, stories of gut biota affecting humans behavior have been documented for a while.

Memory gain is noteworthy, which is the article's "wow" factor, but everyone's just knee-jerk smirking so ... here's a few random articles to gross you out about the wild world of trading microbiota and, for better or worse, changing your personality:

  * "My butt made me crave candy."[1]
  * "Gee, I'm not bipolar anymore thanks to my husband's butt juice infusion."[2]

Crazy, right?

   [1] https://www.psychologytoday.com/us/blog/the-behavioral-microbiome/202404/hacking-an-individuals-personality-through-their-gut-contents

   [2] https://www.abc.net.au/news/2025-07-28/faecal-microbiota-transplant-credited-with-curing-bipolar/105541522

seethishat 2026-03-12 18:47 UTC link

IMO people should eat more fiber. A lot more fiber. It cleans the gut, the liver, absorbs cholesterol, slows insulin response and makes you feel full longer. The microbes in our guts need it to function.

Rather than jumping from one fad diet to another, just eat what you like and be sure to get a lot of fiber each day.

mustaphah 2026-03-12 18:47 UTC link

Yeah, it's a mouse study, but there are tons of human studies backing the whole gut-brain connection. There are even a bunch of books on it [1][2].

What's really cool is that the paper used low-dose capsaicin (just 5 μg/kg injected), and it completely restored hippocampal FOS activity and memory in older mice. Basically, that's the same stuff you get in cayenne pepper supplements - pretty easy to get your hands on.

[1] https://www.goodreads.com/book/show/28837738-the-mind-gut-co...

[2] https://www.goodreads.com/book/show/35210457-the-psychobioti...

riazrizvi 2026-03-12 19:26 UTC link

Great info. This is one of those things that it is much faster for an individual to take into their own hands to prove out, rather than waiting for the system to provide us with an answer. Too many decision makers who are unlikely to all be aligned with our own individual interests.

nothrowaways 2026-03-12 19:38 UTC link

> They showed that colonizing the guts of young mice with this bacterial species inhibited their performance on the object recognition and maze escape tasks, and that this deficit correlated with a reduction of activity in the hippocampus.

dharmatech 2026-03-12 19:41 UTC link

The book

"Why Isn't My Brain Working?"

by Datis Kharrazian

published in 2014 talked about this over a decade ago.

hi_hi 2026-03-12 20:00 UTC link

For those who may be interested in learning more about the gut and how it affects your body and brain, this is a great, accessible, read

https://www.amazon.com/Gut-inside-story-bodys-under-rated/dp...

Also, while we're on the topic, if you ever find your self at the other end of the world in Tasmania, I highly recommend a visit to the MONA museum, which houses the Poo Machine.

https://www.abc.net.au/news/2017-11-07/mona-poo-machine-join...

kseniamorph 2026-03-12 20:25 UTC link

i like how this research (and others related) kind of supports the idea that free will might be lacking. I still keep a pinch of skepticism about this idea, understanding that it's just a concept. But personally i like it, because it even fells a bit relieving... not to say that it helps you abandon responsibility, but it makes your stance on life easier, and pushes you not to blame yourself too much for your weaknesses.

Fricken 2026-03-12 20:50 UTC link

I got into bicycle touring a few years ago, and it’s an ultra-endurance activity which means burning 3- 4 times as many calories as I would on a sedentary day. My training rides were all local weekend overnighters in preparation for the big 1000 mile challenge ride, and they were no big deal.

On the big ride, about 3 days in I started experiencing bouts of intestinal distress which would put me into some of the blackest moods I can recall experiencing as an adult. My whole thought process broke down and I became ruthlessly nihilistic about everything. I was ready to tell my partner to go fuck himself, chuck my bike off a bridge and take an uber to the nearest airport.

But then when the intestinal distress subsided I came back to my senses and I was like “WTH was that all about?” It happened several times, to varying degrees of intensity over the 10 day tour. My eating strategy improved and I bought some cannabis which helped my manage the issue and I was able to complete the tour.

That was a few years ago and I’ve never experienced the black mood again. It has prompted me to believe that the mind-gut connection is much stronger than we might have been giving it credit for, and if you suffer from mood or cognition issues, big or small, you may want to investigate whether your guts and gut flora might be playing an influential role.

theshrike79 2026-03-12 21:28 UTC link

"You" don't crave stuff, the microbiome in your intestine craves stuff.

There are microbes in there that specialize in eating, say, sugar. You don't give them sugar, they send signals to your brain saying "yo, more sugar"

This is why if you go on a sugar-free diet (just stop eating candy and sweets) the cravings just go away eventually. The microbes who keep shouting for more sugar either die away or go dormant.

gcanyon 2026-03-13 00:30 UTC link

>they treated old mice with a molecule that activates the vagus nerve

Anyone know what molecule and treated how?

m463 2026-03-13 02:38 UTC link

unrelated but maybe interesting...

I had a colonoscopy and had to empty my system.

I had 1/2 gallon of this fluid to drink the night before, and the other 1/2 gallon to drink the day of. At that point my digestive system was empty.

I will say with an empty system I felt energized and a lot more clearheaded.

I wonder if doing this from time to time is helpful to your system, and furthermore if eating smaller portions would be helpful to my energy levels.

robwwilliams 2026-03-13 03:13 UTC link

Very well done study with a cautious interpretation of potential translational relevance in humans.

The paper is open access. The discussion does a fine job of providing a full context for interpreting their findings.

https://www.nature.com/articles/s41586-026-10191-6

lsc4719 2026-03-13 03:18 UTC link

You are what you eat.

sn0n 2026-03-13 06:52 UTC link

Yogurt and pickled things acquired.

SilentM68 2026-03-13 07:17 UTC link

That makes sense. I am of the opinion that the gut-brain connection exists. It is real in my view. A healthy gut promotes better mood and health. A parasite-ridden gut leads to all sorts of issues, including anxiety, irritability, stress, constipation and its counterpart, cancer and mental decline. I am doing a gut cleanse now to rebalance my intestinal flora and hopefully remove any bad actors from my gut resulting from years of ingesting processed foods. Want to make sure no parasites accompany me on my upcoming medical imaging visit.

iammjm 2026-03-13 11:55 UTC link

I believe there is a lot of shame-induced ignorance around this whole subject. Culturally poopin' is in the similar category like sex or death, outlawed from most "civilized" debates. But consider how central digestion is to our existence: basically almost before everything else we must consume -> digest -> expel first. You are not getting that smart brain of yours without that poopy butthole to go along with it

FrustratedMonky 2026-03-13 12:01 UTC link

Article doesn't mention any particular foods that would help.

Is it the typical, eat more fiber, more non-processed, Mediterranean? And this is just showing yet another thing that diet impacts? A link exists, but no specific types of diet to help with aging?.

youknownothing 2026-03-13 14:47 UTC link

Unless I misread, I found interesting that exposing young mice to old-mice bacteria makes them behave old, but exposing old mice to young-mice bacteria doesn't make them behave young. I wonder if there is something in old-specimen bacteria that wins over young-specimen bacteria.

hbcondo714 2026-03-12 18:24 UTC link

I would recommend the site https://gutbrainaxistherapeutics.com for learning more about Microbiota Transplant Therapy (MTT) and its opportunities, especially for Autism and Pitt-Hopkins Syndrome.

IshKebab 2026-03-12 19:06 UTC link

It doesn't seem to link to any data at all so we can't check, but I wouldn't be entirely surprised if they used the "standard" P=0.05.

I think for something this unexpected you'd want a much lower P.

memonkey 2026-03-12 19:08 UTC link

The post is about a scientific study and your response is your opinion with nothing else to back it up?

jimkleiber 2026-03-12 19:16 UTC link

There was a South Park episode about this years ago where everyone was trying to get it from Tom Brady.

zinkem 2026-03-12 20:06 UTC link

I believe this research is totally true-- I had a lot of memories come back after

1. I stopped drinking heavily and using other drugs, i.e. marijuana

2. managed my diet to avoid heartburn without medication

3. schedule my meals so it was easier to sleep at night (always eat something for breakfast when I wake up)

I did not need any "poo infusion" or anything.

I had a gal bladder removal that didn't fix the problems the doctors thought it would and got a lot smarter about the kinds and variety of food I eat.

I believe alcohol in particular was really screwing up my gut biome and entire digestive system.

behehebd 2026-03-12 20:35 UTC link

To do this eat stuff that grows and not further processed.

rossdavidh 2026-03-12 20:42 UTC link

Agreed, but I think the mechanism relates to different microbes. If there are two microbes in your gut, and type A requires a dose of high-calorie, low-fiber food coming down the pipe every day, and type B is not able to reproduce as fast as type A but is able to live on high-fiber food, this tells you two things:

type A cannot have been living in humans thousands of years ago, but type B might have

type A benefits from making your brain worse at choosing healthy foods, and type B does not

Which kind would you rather have in your gut?

jrapdx3 2026-03-12 21:02 UTC link

I've long regarded the great variety of chilis as its own distinct food group. But wonderful as they are for flavoring food, quite often in my home, I'm not sure how much of an effect orally consumed capsaicin has on memory functioning.

Conceivably parenteral capsaicin has different effects on hippocampal integrity or physiology than achievable with ingestion. I'm not familiar enough with disposition of capsaicin in the gut to comment further. My question is whether capsaicin passes from gut into the circulation in any appreciable quantity. I suspect it doesn't but I couldn't say I know for sure. I'll have to add it to the already long list of things I need to look up.

inanutshellus 2026-03-12 21:12 UTC link

"It's not my will, it's the will of the bugs in my butt!" yes, very "relieving."

I kid, ;) but I see your point. The idea that you might, say, struggle to resist candy and sweets and it's because some population of your gut biome is fighting for its life if you don't eat sugar... makes sense.

The idea that "I just cut sugar out for six weeks and my willpower to resist sugar went through the roof" ... not because your willpower changed, but because you killed that part of your gut biome.

cromka 2026-03-12 21:15 UTC link

Let me also introduce you to the new kid on the block, the resistant starch: https://www.youtube.com/watch?v=U6IcMW5Khh4

slibhb 2026-03-12 21:34 UTC link

In my opinion, gut microbiome stuff is massively overhyped.

Here's a study that tried fecal transplants to treat mental illness (and found no effect): https://pubmed.ncbi.nlm.nih.gov/41785480/

The pattern with this stuff is that, when a blinded study is carried out, there's usually no effect.

Mistletoe 2026-03-12 22:18 UTC link

You’ve heard of The Selfish Gene theory from Richard Dawkins but I’ve started talking about The Sefish Tube. If you think about us another way, we are a tube of GI tract that does everything in its life and with its power to simply be full.

bitexploder 2026-03-12 23:45 UTC link

What is free will? In Friston’s predictive processing framework, free will isn’t a force that stands outside the brain and overrides it… it’s what the system calls the experience of higher level predictions outcompeting lower-level ones. The brain is a hierarchical prediction machine constantly minimizing surprise, and what feels like a decision is the resolution of competing models, where your prefrontal self model of who you are and what matters generates a stronger attractor than the opposing signal. The sense of “I chose this” is likely a post hoc narrative the DMN constructs after the resolution has already occurred.. agency as story rather than cause. There’s no ghost in the machine, just a very sophisticated model of a self that includes the prediction that it can choose.

Through the vagus nerve and serotonin availability, a dysbiotic gut amplifies lower level threat and conservation signals, making them harder for higher level prefrontal predictions to outcompete. What feels like weakness of will may partly be the system running on a degraded substrate… the DMN then constructs a story about discipline and character over a causal chain that started in the enteric nervous system.

So, you can’t even really perceive some of this. But you essentially can’t overcome it either. The decisions are made before you thought about it.

Aurornis 2026-03-12 23:50 UTC link

> What's really cool is that the paper used low-dose capsaicin (just 5 μg/kg injected), and it completely restored hippocampal FOS activity and memory in older mice.

There are countless papers published where simple ingredients produce miracles in mice. Most of them don’t replicate.

If you look up most food ingredients you can find someone, somewhere claiming to have used it to produce amazing outcomes in mice. After you read a lot of those you learn not to take individual papers seriously if the claims seem too good to be true.

bitexploder 2026-03-12 23:52 UTC link

What you experienced was the gut-brain axis failing under extreme metabolic stress in real time. 3-4x caloric demand and your enteric nervous system was under enormous strain dysregulation of serotonin production, inflammatory signaling flooding the vagus nerve upward into brainstem arousal states, directly degrading the prefrontal predictions that normally keep your self model coherent and future oriented. the nihilism wasn’t a psychological response to difficulty it was your predictive hierarchy collapsing from the bottom up, the higher level model of who you are and why this matters losing the competition against overwhelming lower level distress signals. The fact that it resolved when the intestinal distress subsided is actually clear indicator that mood and cognition are downstream of gut state more than we like to admit. our gut makes a like 80% of our serotonin or something

Aurornis 2026-03-12 23:53 UTC link

If this was true, sugar cravings would disappear when taking antibiotics that kill those microbes.

The fact that this doesn’t happen should give you pause about this woo-woo theory of cravings.

The reason you crave sugar and fat and other tasty things is that they taste good. You evolved in a world where feeling rewarded and driven to consume more of these was beneficial to survival when food was scarce.

owenpalmer 2026-03-13 00:15 UTC link

> "You" don't crave stuff

False. We do crave stuff. The microbiome contributes to and influences cravings, but the way you're phrasing it is misleading.

InkCanon 2026-03-13 00:17 UTC link

I only have marginal knowledge about neuroscience, but one of my neuroscience professors in class would tell us

"You can cure anything in mice."

I don't know the mechanism why, but you can find tons of papers with incredibly strong results for curing of mitigating dementia, cognitive decline, addiction, etc in mice, but these almost never seen to work on people.

SapporoChris 2026-03-13 03:15 UTC link

I suspect if my guts were forcibly colonized against my will that I might suffer inhibited performance in quite a number of areas.

wao0uuno 2026-03-13 08:19 UTC link

Try intermittent fasting. It's easy. It gives your gut a chance to rest. For me it helped with weight control and slightly improved my overall well being. Later I also eliminated sugar from my diet and reduced caffeine intake to minimum by replacing coffee with reasonable amounts of quality tea. That in turn improved my mood, made me less angry and emotional. I also started exercising a bit. All of that combined increased my energy levels, made me calmer, nicer and a bit more optimistic and happy.

papyrus9244 2026-03-13 10:02 UTC link

Most people who fast report that same "clearheadedness".

meindnoch 2026-03-13 10:17 UTC link

Total crackpot theory.

grvdrm 2026-03-13 14:24 UTC link

Roughly what I follow. I pour chia seeds into everything I eat. Also: edamame, goji berries, green peas. Etc etc. My particular motivation is 1) health, but 2) I lift quite a bit and try to get as much protein from food as possible.

biophysboy 2026-03-13 14:38 UTC link

There are a lot of HN users that think they are better at science because they know about p-hacking and the limitations of animal models.

mustaphah 2026-03-15 00:10 UTC link

Maybe this explain it:

https://www.psypost.org/scientists-just-discovered-that-a-hi...

Editorial Channel

What the content says

Structural Channel

What the site does