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]
[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/1055415221. 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.
Heavy alcohol use and marijuana are both known to impact memory and recall directly.
Discontinuing both of those explains changes in memory. Attributing this to microbiome changes does not follow.
For example
>I stopped drinking heavily and using other drugs, i.e. marijuana
Like the primary change you made was to cut out using a whole bunch of drugs with known, significant neurological effects.
(less/no simple sugars, much more vegetables and starches/fibers, regularly eating 4 corn/20 plant oatmeal few times a week)
But I've been able to cut for months at a time. Whenever the cut happens, I feel my brain sort of "return" roughly a week or two in.
I'm not sure how to explain it other than something like fog clearing. Obviously makes some intuitive sense when you read it.
However, as someone that has consumed alcohol somewhat regularly (sometimes more, sometimes less) since college, it's bizarre to think about that consumption in retrospect. In effect, years and years of "fog" - it makes me wonder how different or similar life would have been without that fog.
Can't change the past now, but a data point and strong signal for the future.
theorem of indirection, i guess.
Wow, it must be those gut microbes!
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.
https://pmc.ncbi.nlm.nih.gov/articles/PMC12536323/
It also found the effect was greater in people with IBS.
This is basic ecology, the bacterial population dynamics in your colon are a direct result of substrate availability. If it’s primarily fiber, polyphenols, and other indigestible plant compounds reaching the colon you’ll likely have a healthy microbiome. If instead you malabsorb food from poor lifestyle factors and have macronutrients reaching the colon they’ll probably fuel blooms of pathogens. I think microbiome researchers need to talk with ecologists more to help advance the field out of the myopia it’s in.
FMT does appear useful for special cases of infection like c-diff, but I think that’s led people to believe it’s a generally health promoting practice, when the research simply does not show it.
It must be the case that these microbes need the subject to be aware of their presence! Maybe the microbes have consciousness, and for the treatment to work, the microbes' consciousness has to entangle (via quantum mechanisms) with the subject's consciousness? Blind studies prevent this quantum entanglement to form, that's why the treatment stops working. We definitely need more research in this direction!
Also one issue with all of these studies is they only look at averages and don't do subgroup analysis. It may be that a few patients have an underlying condition causing depression that is highly responsive to these interventions, while it has no effect on the others.
One day people will figure out how to use these correctly.
Microbiome transplant therapy is a domain full of grifters right now who will push it to vulnerable populations desperate for hope, like parents of autistic children. The real research results are much less promising for difficult conditions.
And nobody is bothered by the story. And it gets less clicks. People get cranky when they have been suckered.
This factoid is repeated everywhere but it’s misleading without knowing that gut serotonin is a different pool than brain serotonin and they have different functions.
The brain synthesizes its serotonin locally within the brain.
It is like these armchair scientists don't understand that the actual scientists know the limits of the model system better than they do.
Science depends on accurately reporting facts, being clear about the limits of your findings, and seeking explanations that survive scrutiny. Science journalism has other priorities that are often in conflict with those of science.
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...
"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.
The other thing concerns how potent the effect is to be therapeutic. In many cases, the effect is just marginal to be meaningful.
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.
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.
Can't disagree, but keep in mind that almost all meds are tested first in mice/animal models before human trials verify the effects.
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.
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?
btw people, do drink water to keep up with the fiber. Otherwise it might not help.
Sure sounds like another fad diet.
Yeah! A fad lasting millions of years of human evolution, however.
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.
False. We do crave stuff. The microbiome contributes to and influences cravings, but the way you're phrasing it is misleading.
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.
It does some decimation, but not a full genocide.
The paper is open access. The discussion does a fine job of providing a full context for interpreting their findings.
"Why Isn't My Brain Working?"
by Datis Kharrazian
published in 2014 talked about this over a decade ago.
Edit: one of many examples: https://www.science.org/content/article/journal-retracts-inf...
I think for something this unexpected you'd want a much lower P.
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...
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.
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.
https://www.psypost.org/scientists-just-discovered-that-a-hi...
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?.
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.
Anyone know what molecule and treated how?
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.
#include <gpu_control.h> // g stands for gut
As far as I know, no such effect has been observed.
And this article claims inflamation from that strain, the NIH claims otherwise: "Parabacteroides goldsteinii is a next-generation probiotic gut bacterium with significant anti-inflammatory and metabolic benefits, often reduced in obese or diseased states. "
Not a single one of them has gone anywhere.
> Importantly, vagus nerve stimulation is approved by the Food and Drug Administration as a treatment for depression or epilepsy and to aid stroke recovery.