Autism affects the microbiome, not the other way around | Hacker News Reader

Autism affects the microbiome, not the other way around

arstechnica.com

93 pointswyrm77 comments

> So this study concludes that kids with ASD have reduced dietary diversity because of their behaviors, and this alters the taxonomic composition of their microbiome

This sounds reasonable. Anecdotally autism and OCD can cause strange eating habits.

I’d also like to see a microbiome study done on more neurodivergent individuals to see if this pattern sticks.

Anecdotally, we also have a family where we have to cook separate meals at times because certain foods cause the gag reflex while they eat and they don’t like exploring new foods.

The running joke when my son was younger was that he didn't like to try new foods he hadn't had before.

Fortunately he grew out of it in his mid-to-late teens.

I'm curious how neurodivergent individuals managed to survive in pre-modern times, or even in poor countries today. Throughout most of human history people usually didn't have any choice of foods. They either ate whatever was available, or they starved. The concept of cooking separate meals is a historical anomaly that's only possible in an affluent society with a food surplus.

Most people in the first world nowadays have rarely, if ever, been all that hungry. If you go, say, 14 hours without eating anything while walking in hard terrain/doing physical labor literally anything edible is appetizing. I imagine they got over whatever mental blocks they had quickly.

Yes, but let's be reasonable - not everything that is available as a food can be classified as food(in the sense of healthy food). I, for one, as an omnivore, that shuns extreme food preferences, have a very diverse diet(which includes meat, fish, vegetables) and prepare and cook food myself and my strange habbit is not getting the same food every day, because it gets too boring. Even because of this diverse diet, I still can easily develop some problems, that other people seems to not have eating the same food.

Also, if you think about that - not only smell, but taste and texture can cause sensory overload and if you have eaten something that feels funny, that means that your gut also is sending signals. I have vomited food, that others did not had problems eating, even if that food was probably slighly spoiled - apparently this is something that my gut tolerates less than others.

Let's also think on whom this paper is aimed at - in general people are stupid, like the parent that succumbed to childs demands of food(though, pear is fruit, smoked chicken is meat, waffle is providing hydrocarbonates). So, there are people out there, that has to be taught, that varied diet has to be taught in chhildhood - that knowledge will stay for the rest of your life. If my parents were allowing me to eat only candies, that I was happy to consume in large quantities and not introduced to fish and other foods, that I found repulsive as a kid, then I would be similar to other people, who were not exposed to some foods and still find them repulsive, like in childhood. Some things have to be taught in childhood - like immunity - if children are not exposed to countryside, or exposure to danger - of open flame, etc.

Koalas that are feeding upon specific Eucaliptic trees are not born with those gut bacterias, that are allowing to eat those leaves - they have to receive that gut bacteria via consuming fecal matter of their koala mother - if they are not receiving that bacteria, they are for sure having problems with their diet.

Try hacking Microbiome with different kinds of Probiotics. The gut brain axis is two way. Thus you may be able to lessen autism spectrum dissorder symptoms via Probiotics.

Research articles https://pubmed.ncbi.nlm.nih.gov/28686541/

https://pubmed.ncbi.nlm.nih.gov/34062986/

https://www.frontiersin.org/articles/10.3389/fendo.2019.0050...

> lessen autism spectrum dissorder symptoms via Probiotics

Parts of the HFA experience can be advantageous. I wonder if certain aspects could be enhanced in this manner.

Thank you for the links, very interesting studies on the possibly beneficial effects of probiotic supplements on autistic symptoms.

For my own reference, the probiotic strains mentioned are: Bifidobacteria longum, and Lactobacillus acidophilus/plantarum/rhamnosus.

> Lactobacilli comprise most food fermenting lactic acid bacteria, and are used as starter cultures in industry for controlled fermentation in the production of wine, yogurt, cheese, sauerkraut, pickles, beer, cider, kimchi, cocoa, kefir, and other fermented foods, as well as animal feeds and the bokashi soil amendment.

> Lactobacillus species are dominant in yogurt, cheese, and sourdough fermentations.

https://en.wikipedia.org/wiki/Lactobacillus#Probiotics

This talk at MIT a few days ago measured nervous system disruption in rident guts with autism analogs.

http://calendar.mit.edu/event/exploring_gut-brain_signaling_...

The conclusion is both the gut and brain may be affected by whatever causes autism. But the study didnt attempt to establish whether the gut affected the brain, or the brain affected the gut, or were they simultaneous.

This is an interesting study, but it’s far from the conclusive answer to the question of how the gut microbiome relates to neurological conditions. Given the heterogeneity and complex etiology of autism, a study of this size is not sufficiently powered to pick up all plausible correlations. If there is a causative connection between the microbiome and autism, it’s likely only true of a subset (perhaps a small one) of autistic people.

I’d be shocked if the researchers doing this study didn’t slice up the study participants by various traits and look for correlations. I.e. find the similar individuals (wrt gut microbiome) and group them, then check for shared traits (wrt asd).

> it’s far from the conclusive answer

Idk it feels conclusive to me. The variance in asd gut microbiome is much more than the variance between asd and non asd gut microbiomes. Whatever we call autism is not “caused” by your microbiome. If there is a single trait or “variant” of asd that IS caused by gut biome that doesn’t actually change the truth of the first conclusion.

Would this be the beginning of a trend? I have an intuition that reversing the causal relationship between high-level (psychology, mind, behaviors) and low-level (physiology, disease manifestations) matters can significantly advance medicine.

So if our behavior is the result of neuronal networks processing information, what is the 'causal relationship'

'Higher level' stuff like behavior is the result of our cells communicating, there's no magic 'soul' that act on our biological systems. It generally goes from low->high but there is some feedback that occurs at 'high' and induces changes at 'low'

The reality is a combination and thinking it just goes one way is flawed reasoning. Nothing is unidirectional and nothing is binary

What makes you think consciousness arises from matter? Is it a verifiable hypothesis?

It's far simpler to say it does based on the entire body of our research up until this point than it doesn't so the burden of proof is on those saying that it doesn't.

I don’t think there is much existing research that directly tackles this question, is there any? Meanwhile, there is research[0] that appears to be investigating the potential of such reversed causality or at least something adjacent.

[0] https://www.frontiersin.org/articles/10.3389/fpsyg.2014.0057...

There's tons of research on consciousness in the medical field, as it's directly relevant for many disorders and conditions affecting it.

Is there some research that makes a refutable claim that consciousness arises from matter, and then proves that claim experimentally?

It's literally irrelevant when everything we do to manipulate and track it works already. That's why I said the burden of proof is on the silly philosophical claim that it doesn't arise from matter.

Like when doctors see someone's blood ammonia levels go up and they're suddenly less aware of everything going on, less responsive, less able to talk about their thoughts and less coherent. Or patients with hypoglycemia losing their short term memory and eye sight and ability to make coherent sentences. And how we can do EEGs and directly see declines in electrical activity when this happens.

How could you possibly think that the consciousness is independent of matter at that point? It seems utterly ridiculous.

Blood ammonia level rise correlates with loss of coherence, but a causative link would require direct proof that consciousness arises from matter, and I suspect there is no such proof (the responses in this thread supporting my suspicion).

The other, straightforward interpretation is that there may be a third factor that caused both the high ammonia marker and lack of coherence, and naturally that could be patient’s own consciousness and/or its interactions with other consciousnesses (e.g., alcohol abuse).

Sir there's dozens of different things that alter brain physiology with measurable results in alteration of consciousness. I just took a random example.

Ah yes, but none of those things are the ~one true reason~ for consciousness! Ah ha gotcha!

ignores how systems work together to produce emergent behaviors

My point is that both causal directions are a possibility, and scientific experiment does not seem to have proved one way over the other so far.

I don’t think that it would be verifiable, but it is a default hypothesis that we don’t assume some yet unseen way of interaction between something and our material bodies.

Also, I don’t think that it is unreasonable to imagine “consciousness” happening as an emerging feature of sufficient complexity. Remember, we have 3 billion neurons with orders of magnitudes more connections between them.

I don’t mean some third thing interacting with our material bodies. What I mean is consciousness as the territory, and perceived matter and time-space representation as a simplified map.

Do you have evidence for this? Because it sounds like a larger leap of faith than I have assumed in my post.

No, but neither do I have evidence for consciousness arising from matter. If you can point me to some, I’d welcome that.

Your logic is literally flat earth level sillyness. There's tons of evidence in medicine/biology of consciousness arising from matter.

Flat Earth is a trivially refutable theory, and had been specifically demonstrated to be false.

Perhaps I’m missing something, but I am failing to see the same in case of the “consciousness-from-matter” theory.

EEG signal go up, person awareness go up. Boom. Done deal.

Until there is evidence I’m calling this cargo cult.

Note that the article actually suggests the evidence to the contrary. You make a choice to change your lifestyle, boom microbiome.

Choices are the result of neuronal information processing which can, in some ways, be impacted by diet and microbiome. It goes both ways.

I'm not sure you and I have the same definition of "awareness"

An organism can detect something, be aware of it, by sensing it. This involves some stimulation and then neuronal transmission, the processing that happens determines if the stimulus reaches conscious awareness as not all stimuli does.

To add to this, conscious awareness can be equated to all thought processes. Thought processes are an internal representation of signal processing some by the communication networks of the brain and other associated systems (mostly neurons/glia but other systems do have impact on processing in various ways)

It is abundantly clear that this is your position. What I was asking for is reasoning / research / evidence to support the idea that thought processes are representations of neuronal activity and not the reverse.

https://news.rub.de/english/press-releases/2021-05-20-neuron...

https://pubmed.ncbi.nlm.nih.gov/15505972/

https://www.frontiersin.org/articles/10.3389/fnins.2019.0116...

You are ignoring what I write. My point is that those neurons that move prosthetic arm may be consequences of conscious activity, its indicators if you will. I won’t read the rest of the links.

Does computation in computers arise from matter?

If matter arises from consciousness, then by extension so does computation.

I’m not saying it as a fact, as it is neither refutable no verifiable—but neither is the conventional view.

The explanation that I offer is note plausible than the conventional view (magic souls)

Perhaps I'm wrong, but it at least seems like a step in the right direction where the hypothesis is based on already verified behavior of neurons and their networks

The problem with the consciousness is that by default it is limited to ability perceive senses and bacteria clearly is beyound our limits of consciousness, but that does not make them less real. Our brains collect and process information subconsciously - the layer of our consciousness is not responsible for all the background work, that our brains are doing. There can't exist hypothesis in regards of gut processes affecting very thin layer of consciousness.

So, but can you disprove that gut bacteria can't impact brain processes? They can deliver signals to the brain, so what is exatly the obstacle that it makes it impossible task?

First I would like you to define consciousness

Perhaps you could give an example by defining “matter” or “reality” or whatever you believe is the underlying territory?

(Without circular definitions or those involving consciousness, of course.)

I don't understand how there could be circular reasoning involving consciousness when explaining what matter is. I am not a physicist so I will stick with the chemical definition. Matter is made up of atoms, which are made up of proton, electrons, and neutrons. These particles interact and react to form ordered structures which have new emergent properties. These systems build on each other to create new systems such as cells which make up organisms which is what you and I are.

You skipped the part where it is the matter that your consciousness observes.

Ah I see, that's a good method of writing off evidence arbitrarily!

If we cannot agree that objective observations can be made and shared from the perspective of a human, then it's obvious that you will just write off everything after that point and this conversation is meaningless. This agreement is generally implicit when discussing the results of research.

I am not writing the evidence off, merely pointing out that you are observing correlational evidence, and causal link in one particular direction is your conjecture.

Well, if I remember, then there was an article about that some bacteria that was present in brains was also present in gut.

The very quick stupid idea was that bacteria from guts was invading brains, but there might be other explanations to that - bacterias are also living outside gut and if some of them somehow are finding a way into the brains, that does not mean that they came directly from guts. Might be - might be not and brains might have other canals that allows bacteria to enter and once they are in brains, they might be able to get control over things and condition brains in favouring specific gut bacteria, by requesting - craving specific food. So, I don't see that this research has nullified those ideas about bacterias affecting brains and helping their species of bacterias without knowing about them. But what this article is proposing is not illogical - not getting into demands of zombified controlled brains hold hostage of bacterias, or actually - developing healthy dietary habbits, by favouring diversity of gut bacterias in first place.

It is also probable that both autism and altered micro biome are co-arising conditions with an underlying genetic link. Many genes implicated in ASD are also genes that can effect the mucrobiome.

If you want me to explain this more let me kmow.

I doubt that. It's likely both; as with most things in nature.

> They also “failed to replicate previously reported ASD-gut microbiome associations,” identifying only one species (out of 607 examined) that significantly differed in abundance between kids with and without ASD.

Not everything is a two way street. Cancer doesn’t cause smoking.

Cancer doesn’t cause smoking.

At the risk of sounding nuts: We don't know that.

There are various infections (often parasites) that mind control their victims and get them to engage in bizarre behavior that serves the goal of the parasite to reproduce.

I think ants infected with a particular fungus or parasite crawl to the top of grass stalks, making it more likely they will get eaten by cows which serves the reproductive needs of the infection.

Rats infected with a particular parasite are more aggressive and less likely to avoid cats. Getting eaten by a cat kills the rat but serves the reproductive needs of the parasite.

If cancer is caused by some infective agent that alters the right things in the body, maybe that makes it more likely that you will smoke, thus promoting the kind of environment that serves the infective agent so it can pass some threshold and become "cancer" when it's not recognized as such below that threshold.

Lotta mental gymnastics there, but ok, so some infectious agent causes cancer and smoking. That’s still not cancer causing smoking, that’s toxoplasmosis (or whatever) causing both.

You’re, of course, right in one sense - I can’t prove a negative. Cancer might cause smoking but we haven’t found the link yet. But the lack of evidence is suspiciously large at this point.

It's not a lot of mental gymnastics. We know some cancers are, in fact, caused by viruses. For example, human papillomavirus causes cervical cancer, so (iirc) women with fewer than 20 sexual partners are less likely to get cervical cancer because they are less likely to have contracted human papillomavirus.

But the lack of evidence is suspiciously large at this point.

Such evidence will not be found if we never look because we already assumed the conclusion and dismiss those thinking out loud as nutters engaging in a lot of mental gymnastics.

Edit: https://www.cdc.gov/cancer/hpv/basic_info/cancers.htm

Again all you’re doing is providing a mechanism for how some infection could cause cancer AND smoking - not smoking causing cancer. That’s an easy one to find evidence for… just look for the co-occurrence of smoking, cancer, and this infection. Sorting out which causes which is hard but not impossible after that.

To find smoking causing cancer you’d have to find smoking increasing amongst people who get cancer. I don’t have studies to point to but i’m pretty sure that’s been looked at. By the tobacco companies if nobody else

No, you are getting off the rails here - to prove that cancer causes smoking you have to provide real life example of a non smoker, where after getting cancer, a patient starts to smoke. That patient might be some kind of exception, but this does not work for cancer patients at all. So, cancer akkktually does not cause smoking and there is no way to prove that, unless you are thinking of developing mutation of cancer that carries some mutagen, that as a side effect also causes patients to start smoking, but let's be real...

And it is not smoking that causes cancer, but exposure to chemicals, that causes cancer. And only if that exposure is critical. For the same reason you are able to take x-rays, but not often. So if you are smoking peace pipe ceremonially once per occassion - this is not going to cause you a cancer.

to prove that cancer causes smoking you have to provide real life example of a non smoker, where after getting cancer, a patient starts to smoke.

No, I wouldn't. I would have to prove, for example, that someone started smoking after getting human papillomavirus and that there was a mechanism plausibly linking the infection with the craving for cigarettes.

I don't readily know how to make the linguistic distinctions I want to make here. Sure, if you want to say "They first have to have a diagnosis of cancer..." okay, I'm dead in the water.

That's not what I'm suggesting. I'm suggesting that we don't fully understand what causes cancer so it's possible that whatever living thing is a factor in causing cancer may also alter behavior such that it makes a diagnosis of cancer more likely.

This is probably not worth discussing further. "You cannot solve a problem using the same mental models that created it" but those "proven" mental models are a handy means to dismiss someone in conversation as getting off the rails.

> No, I wouldn't. I would have to prove, for example, that someone started smoking after getting human papillomavirus and that there was a mechanism plausibly linking the infection with the craving for cigarettes

Thar wouldn't prove cancer causes smoking (or prove anything), but it would suggest the potential of a common cause between cancer and smoking.

Yes, I just said that.

I think I'm done here.

Hey, English is not my native language and "getting off the rails" here was meant, that you are leading yourself astray and falling off the cliff. I mean you are losing track of this debate that smoke is causing a cancer.

But to be fair, I can't see sense of following other logic of yours, because I recently lost a relative to a cancer and there was absolutelly nothing to blame for, except that she got into toxic environment, which killed her.

Also, if we come to that - did you know, that in UK there were cases, that spouse was poisoned by chemicals, that causes cancer - are you aware that there are thousands of medical drugs, that has side effect that might cause cancer? How are you going to explain those with your logic? So, apparently person is developing a disease, and in process of treating that disease, person develops a cancer... good luck in explaining that with behavioral impact, like you are trying to do on fixating on HPV, which is only one of thousands viruses that can potentially damage cells and eventually damage cell programming and cause a cancer.

HPV is causing deformations of human cells. That is basically definition of what cancer does, only cancer is caused by wrong cell service programming itself - not by viruses. HPV itself can't cause cancer upon entering human body - there has to be development of mutated cell, that starts to spread cancer. If you think, that HPV causes behaviour, well... hard luck, you can end up by blaming your parents.

Give your kids a vaccine against herpes and HPV and stap worrying about something you can't affect and reading those articles is not going to help, knowing that (constant)stress also causes cancer. Not intended to be rude, but women are more affected by hormones and no sex also can cause cancer. You don't have to be smoker and can eat healthy to get cancer nowadays, but to prevent degradation of cell programming is responsibility of genes.

Could be going down the rabbit hole with this comment, but cancer is an extremely generic term - lots of different organ and cell types. And smoking is also less well defined than one might think - additives to cigarettes and paper are not, I believe, considered in most studies. And not all smokers develop cancer. I had two relatives who were heavy smokers and lived until their late 80s and didn't die from cancer. To summarize, there is lots that we don't know about cancer.

So I would agree that this could be out of the box thinking that could have some truth to it. But I also doubt that research will be done in that direction unless there is some proof that justifies the expenditure. So we're likely to not know for sure, and most will assume it's not true.

While demonstrating that autism influence the microbiome seems not especially tricky, demonstrating that the microbiome does not also influence autism seems next to impossible.

I think obviously it's a two-way street. There are many factors here. They seem to be oversimplifying the issue, which is perhaps understandable but will lead to erroneous conclusions rooted in bad mental models.

Maybe. Humans developed their brains mainly because primate ancestors ~3 million years ago started to hunt other animals(including other primates) for meat and eat cooked protein rich meat, which allowed to develop and maintain bigger brains. That affected more diverse gut bacteria of primates - they lost ability to process raw meat more efficiently, because there was no more need for that.

My take is that in overall ASD is next evolutionary change in brain development, where things that were coming from natural animal world are given away - that includes easy and intiutive social interaction that monkeys have, filtering of visual and sensory information that is bombarding our brains, where normally humans ignore 80-90% of information that brain receives and that includes gut behaviour as well. Apparently this brain development change can come together only with prolonged life.

I would wager that autistic people are less likely to have children, which means that humans are evolving away from autism (assuming a large enough hereditary factor).

The evolutionary benefits of a dominant allele can vastly outweigh the negative consequences of a recessive one, keeping it alive even though it reduces fitness of some individuals. With a spectrum disorder like autism that's likely caused by many factors, we can't even hazard a wild guess.

My autistic cousin that can’t function on his own would differ, if he had the mental capacity to do so. The spectrum is wide and people on the light side (or that know people that are) have a skewed view of things.

I remember when I heard people saying a better gut flora could treat autism alarm bells started ringing about microbiome stuff being way overhyped for me.

This causal direction makes sense though.

I dunno, we're making a lot of discoveries about how our gut influences our health, e.g., https://www.science.org/content/article/your-gut-directly-co...

The micro biome is lauded everywhere and considered as the last great frontier of medicine which will solve all human ailments. There is barely any disease that is not regarded as being potentially caused by the micro biome. It’s all complete horse shit.

After going through the worst burnout of my life from 2018 to 2020, I have proof in my own life that diet and digestive issues are hugely correlated with cognition and mood.

Personally, I don't expect these kinds of studies to find a smoking gun. The chemical interactions between foods and the immune system are far too complex to be understood at this time. The immune system is the second most complex biological system after the brain. But we can still get clues. I highly recommend the everlywell comprehensive test (no affiliation) of 200+ foods, which I took that confirmed my suspicions about certain foods:

https://www.everlywell.com/products/food-sensitivity-compreh...

There's also a regular test of 100 foods for about half that price. And yes, these tests have their flaws, but can still inform us.

I've also been taking ashwagandha for a few months for ADHD symptoms (still undiagnosed, but I'll get to it, I swear!) after hearing good things about it online. I'm an INFP with 78% on intuition, so I'm somewhat cursed with knowing the solutions to problems before people finish explaining them to me. Which is great for programming, but debilitating when living in a sick society healing from recent events in these times. My "deficits" (should really be differences) are around dissociation because it's too easy for me to slip down interesting rabbit holes. Living and working in the malignant mundanity of The Matrix while knowing a better world is just beyond our reach due to dogma, takes everything I got, every single day.

Attempting to keep this brief, I believe that ashwagandha may desensitize the immune system to nightshades, which are pretty much all of the fun foods. I also suspect that it raises the proportion of good bacteria in our gut that live on roots. Humans evolved as scavengers eating icky things, but our surroundings and food are too sanitized today, so autoimmune issues and inflammation will eventually come to dominate our medical system.

Which was the plot of a 1990s sci fi series called Earth 2, where a billionaire's kid gets "the syndrome" from living in too sterile of an environment:

https://en.wikipedia.org/wiki/Earth_2_(TV_series)

So people have known about this stuff for a long time.

For anyone curious, the way I got out of burnout (severe anxiety, I learned) was by completely shutting down for a few months and taking care of the chores I had put off for years/decades. I had to relearn how to break overwhelming tasks down into simpler steps on my todo list and just do what I could each day, even if it was only one thing or getting out of bed. But more importantly, service. I let my ego finally die and gave myself over to helping others. That was the missing piece we don't hear about in a capitalistic/patriarchal "me" culture.

Kids are very bright, often just as capable as you and me (you remember) but forced to endure eons of slow growth before they are free. I think we'll find that most developmental "disorders" are clues as to what's wrong with our society, and that as we all heal and ascend, they'll begin to subside.

There's a lot of research that contradicts these notions, and also practical advice on how to remedy through food choices, if one is inclined to look into it. As with anything, it's a controversial subject, probably due to the severity of autism and the real difficulties of changing one's diet radically.

http://www.doctor-natasha.com/gaps-book.php

https://www.medicalnewstoday.com/articles/325046

https://www.goodreads.com/en/book/show/978904.Gut_and_Psycho...

those 3 links are effectively from a single source, Dr Natasha Campbell-McBride, who hasn't practiced as an MD for what looks like 20 years. She makes a living out of that miracle diet. She's anti-vax and hasn't published any research about GAPS.

I think her whole scheme is dangerous and would recommend everyone who's considering this diet to look at the negative press around the diet and its proponent. You'll have to look pretty deep into google results to find those, but they're there. I'm not linking them because I'm not qualified to judge their quality besides superficially.

My son has autism. I'd say he's slightly below 'moderate' on the spectrum. We first started him on the GAPS protocol ~5 years ago. We've since evolved our approach and moved onto other dietary protocols (of which there are many—part of the difficulty with studying or treating autism is that it's a diagnosis of a set of behaviors, not of an underlying condition: the underlying conditions are many and varied), but that was the first time we tried something that resulted in observable, material improvements in his quality of life, across a number of different vectors.

When the healthcare establishment shrugs its collective shoulders and tells you that your son is condemned to a life of physical suffering, and being trapped in his own head, you don't wait for the 'experts' to publish studies. You go to work.

The linked article addresses research like this directly.

The subjects of the article did the first high-quality research on this topic in humans.

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