Reversing memory loss via gut-brain communication

(med.stanford.edu)

188 points | by mustaphah 6 hours ago

16 comments

  • inanutshellus 4 hours ago
    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
    • zinkem 2 hours ago
      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.

      • y-curious 2 hours ago
        What did you do for heartburn? Just looking for ideas. I noticed reducing gluten helped me personally a lot
        • throwawaytea 32 minutes ago
          Im not saying to live this way, but a super restrictive test diet may open your eyes to some thing and then you can add back.

          I even once read that someone noticed an issue they tried to clear up for years with doctors went away on day 3 of a water fast. No, he wasn't going to fast forever. But he was shocked the first relief he ever had was that day. From there he solved his problem once his eyes were opened a bit.

          I'd personally try all ground beef for a week or two. It won't kill you. Is it ideal? Probably not. But you will not have any problems from that short trial. Then add things slowly until you have a whole good diet you like.

        • ratg13 14 minutes ago
          It might not be gluten (protein) that is affecting you, but the fructans (carbohydrates) that are found in wheat, rye, and barely which are high in FODMAPs.

          Look into low-FODMAP diets if you haven't already.

        • ekaryotic 1 hour ago
          not the commenter but I bake my own soda bread and found that i was getting heartburn from the salt that was in the recipe. once i eliminated that i could eat as much as i wanted. I also cannot eat salt preserved potato chips on consecutive days.
        • colordrops 1 hour ago
          There are many resources online on which foods trigger gerd and reflux. Also, try the whole30 anti inflammation diet, and don't eat at least 2, preferably 4h before bed.
      • XorNot 2 hours ago
        Your hypothesis here though is full of complicating factors.

        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.

    • slibhb 1 hour ago
      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.

      • esperent 1 hour ago
        Here's a meta analysis of 12 studies showing that FMT has a significant effect in reducing depression:

        https://pmc.ncbi.nlm.nih.gov/articles/PMC12536323/

        It also found the effect was greater in people with IBS.

        • BizarroLand 12 minutes ago
          I wonder how that study would fare against a double blind where some people get FMT and others do not, but they are both given the same attention and care otherwise over the course of the study?
      • andrewl 1 hour ago
        Replying to slibhb, while the research involving mental illness is not conclusive, fecal transplants are a known and accepted treatment for persistent C. diff (Clostridioides difficile) infection. Just for the record.
      • butILoveLife 1 hour ago
        You are probably right on the specifics, but serotonin is produced/located in the gut, and its an incredibly important neurotransmitter.

        One day people will figure out how to use these correctly.

    • hbcondo714 4 hours ago
      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.
      • y-curious 2 hours ago
        I’ll dig in more but my first question when I see this: who are the donors exactly? Like who decides what the ideal gut microbiome is and that John Doe is the guy to provide his fecal matter to the masses?
        • ratg13 8 minutes ago
          You either need a lab to test donor samples first, or when this was more of a craze, a popular source of 'donations' for the DIY crowd was young children from the same family.
    • eek2121 1 hour ago
      Not only are there tons of papers, there are off-label treatments (some that have improved more than 80% of the folks I'm about to mention), and this isn't just about age related decline, but cognitive impairment in general. Long COVID, ME/CFS, TBIs, and other conditions are widely considered to have a similar origin. If you are interested in this stuff, I encourage you to look up all the scientific papers on this. It is fascinating stuff.
    • jimkleiber 3 hours ago
      There was a South Park episode about this years ago where everyone was trying to get it from Tom Brady.
    • 1shooner 4 hours ago
      This seems to be a recent anti-science meme to dismiss studies that use mouse models. I'm sure there is an interesting line of discussion about the strengths and limits of those models, but that's probably a complex, nuanced thread to pull, not something you blow off with a hand-waving internet comment.
      • inanutshellus 4 hours ago
        To some degree the other posts are just pointing out the misleading "assumed protagonist" of the title (which doesn't mention mice) but I was surprised to see that the majority of posts boiled down to "eek! mice!"
      • MarkusQ 1 hour ago
        It's not anti-science, it's anti-science-journalism-hype.

        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.

      • znpy 3 hours ago
        I bet it started with people trying to 1-up other commenters via the usual “achtually…” and then proceeding with the “in mice” notice.
  • mustaphah 4 hours ago
    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...

    • jrapdx3 2 hours ago
      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.

  • seethishat 4 hours ago
    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.

    • rossdavidh 2 hours ago
      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?

    • behehebd 2 hours ago
      To do this eat stuff that grows and not further processed.
    • cromka 1 hour ago
      Let me also introduce you to the new kid on the block, the resistant starch: https://www.youtube.com/watch?v=U6IcMW5Khh4
    • memonkey 3 hours ago
      The post is about a scientific study and your response is your opinion with nothing else to back it up?
      • igleria 3 hours ago
        they IMO are trying to help by giving good ideas to keep a healthy gut. Add that to the study and at least to me, it´s a nice idea.

        btw people, do drink water to keep up with the fiber. Otherwise it might not help.

    • jstanley 4 hours ago
      > eat what you like and be sure to get a lot of fiber each day

      Sure sounds like another fad diet.

      • lelele 2 hours ago
        > Sure sounds like another fad diet.

        Yeah! A fad lasting millions of years of human evolution, however.

      • vablings 3 hours ago
        This has been the recommendation for general health for as long as I have been alive. Fiber is really important and there are plenty of easy healthy options that are cheap, unlike the astroturfed beef checkoff primal diet
      • nomel 3 hours ago
        The charitable interpretation is "just eat more fiber, regardless of the rest"
  • theshrike79 1 hour ago
    "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.

    • Mistletoe 47 minutes ago
      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.
  • dharmatech 3 hours ago
    The book

    "Why Isn't My Brain Working?"

    by Datis Kharrazian

    published in 2014 talked about this over a decade ago.

  • hi_hi 3 hours ago
    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...

  • ArchieScrivener 31 minutes ago
    So drinking turpentine will cure my homosexuality?
  • riazrizvi 3 hours ago
    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 3 hours ago
    > 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.
  • kseniamorph 2 hours ago
    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.
    • inanutshellus 1 hour ago
      "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.

  • maxall4 5 hours ago
    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...

    • IshKebab 3 hours ago
      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.

  • behehebd 2 hours ago
    Say the line HN!
  • Fricken 2 hours ago
    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.

  • steve1977 5 hours ago
    [flagged]
    • j45 5 hours ago
      in mice is clearly in the subhead.

      The connection between gut-brain has been studied in humans, as well as the effect of diet and gut bacteria on brain functions.

      • vidarh 5 hours ago
        And in this case it sounds like the pathway to determining if this has an effect in humans as well might be relatively short given there is a pool of patients receiving vagus nerve stimulation for other things that might provide data.
        • j45 4 hours ago
          Vagus Nerve treatments also exist as well and are highly observable.
  • fnord77 5 hours ago
    ... in mice. So if any of this held in humans, I think you'd see reversal of old-age memory problems in people treated with antibiotics that kill Parabacteroides goldsteinii.

    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. "

    • vidarh 5 hours ago
      It's possible the specifics are different but that the overall idea still could work for humans. It seems worth at least exploring.
  • theusus 5 hours ago
    Mice mice mice. Tell me when you test on humans
    • BizarroLand 10 minutes ago
      In theory you would never test on humans directly. You would go through various order testing and slowly work your way up to a final verification on human subjects that has almost no chance of going wrong and that the worst possible outcome is that nothing happens.