Many autistic children have extremely limited diets. For example, a geneticist friend of mine saw a case where an autistic child had been referred for genetic testing because of horrific, chronic, spontaneous wounds on gums and skin. Turned out to be scurvy, because he had exclusively eaten Wheat Thins for the last 3-4 years, which aren’t fortified with vitamin C.
I would fully expect that a monotonous diet leads to a heavy skew in the gut microbiome as specific bacterial species that thrive on that diet are selected for, others against. It makes some sense that a fecal transplant could repair the damage. If the diet has shifted or expanded, the transplant could lead to long term benefits by restoring newly-viable bacterial species, perhaps by facilitating digestion of the new types of food.
I’d be curious to see a factoring out of the diet composition, gut microbiome, genetics, and severity of autism symptoms.
The microbiome might have some modulating effect, but the fidelity of gut-brain axis communication isn’t so strong that our gut microbiome is driving us around with highly specific inputs.
The theories for how gut-brain axis modulation works include altering the balance of nutrients that get absorbed and modulating the vagus nerve, primarily. For someone with autism it might be possible that altering some of these balances could make the condition better or worse, but that’s all theory without much foundation.
What is known, however, is that diet has a massive impact on the microbiome. Even the mechanism for that is obvious: Bacteria thrive on different foods, so if you eat more of one class of nutrients and less of another then the microbiome proportions will adjust based on which ones thrive on that diet.
I’m not going to pretend to be an expert here, but I remember a study that found gut bacteria composition predicted whether or not an individual was chocolate-craving or not in individuals eating identical diets: https://pubmed.ncbi.nlm.nih.gov/17929959
putting aside what others have commented about the truastability of studies and similar
- what all studies show is some vague "craving" for something generic, e.g. the link between iron deficiency and craving for ice
- but what you see in autists is often a far stronger effect and not just for eating something, but also against eating most other food. A craving for chocolate does not remove appetite and willingness to eat other food. It just makes you really want to eat chocolate.
- more important the way autistic people get fixated on a monotonous diet is far more specific then any effects we have observed from gut bacteria or other similar sources AFIK. Like lets say your gut bacteria might make you crave fish. You autism on the other hand might make you crave dino formed fish sticks with a specific texture. And there is just no way gut bacteria care about your fish sticks being dino formed or the specific texture of them... But a autistic person often does care, quite a bit even.
Yes, restrictive behaviors and powerful adherence to familiar routines are a general feature of autism. It’s not specific to food. The comments trying to draw complex links between food cravings and these behaviors are missing the fact that this type of behavior is not limited to foods. Food is only one area where it might manifest.
Mine is just an anecdotal experience but I have Asperger's and the reason I eat the same food is not about disliking other food. I actually like most food. I eat the same stuff because:
1) Eating the same food frequently means I don't have to spend any of my cognitive cycles on deciding what to eat.
2) I know that this food will sit alright with my digestive system. Everyone I know personally on the spectrum has stress-related digestive issues.
For snacks and small meals I will eat citrus or microwave a small sweet potato and this helps with Vitamin C.
Autistic adults are not children and using dino-shaped fish sticks probably does not represent most adults on the spectrum.
You have to be careful with microbiome research because it’s a buzzword that gets crammed into a lot of research papers to imply something bigger. This is a single paper from Nestle Research Center (yes that Nestle) from 2007 that doesn’t even cite a number of people sampled in the abstract.
They didn’t run any experiments trying to change the diet or microbiome. They just correlated dietary preferences with some markers that might be correlated with the microbiome.
The paper does not say anything about how changing the microbiome might change preferences. The simplest and most well tested explanation is that dietary preference are driving the microbiome.
There’s a lot of woo-woo microbiome discussion out there that misses the really obvious basics of how the microbiome comes to exist and thrive: What you eat is what the microbiome eats, so changing what you eat will change the composition of bacteria that thrive. People who prefer chocolate are correlated with people who prefer sweet diets. High sugar intake is proven to alter the microbiome.
It makes sense for chocolate given that cocoa flavanols are prebiotic fiber for GABA-secreting bacteria which of course affects the parasympathetic nervous system.
The paper didn’t say that the microbiome was driving food preferences.
It measured some bio markers and some dietary preferences and claims some correlation.
The correlation is that what you eat fuels the microbiome. So your diet influences the microbiome by fueling or starving different bacteria.
Complex theories about causality going the other way through complex chains of flavonoids to bacteria to neurotransmitters to the parasympathetic nervous system sound impressive with all of the big words, but it’s such a complex theory that would need other testing to even begin to understand if there was something there.
Testing the other direction is easy and obvious. You can grow many bacteria in a Petri dish and see that some grow better or worse with different nutrients.
But is it driven by a desire for the diet, or a desire against things that provoke an undesirable reaction?
I am forced into an extremely limited diet to avoid provoking my body any more than I have to. And, notably, one of the first reactions used to be something not tasting as good as it used to (or in one case tasting worse than it had.) It doesn't always happen but when it does it's a near 100% accurate test--the only time it ever fooled me the actual culprit turned out to be something my wife put on her face.
I saw what happened to my mother (very similar path, but started much later in life), I already knew how to isolate what was giving me trouble before it ever happened. Most people don't, though, especially when dealing with things where it isn't high on the ingredients list (or, sometimes, not at all--they are strong about requiring manufacturers to list what they put in, but there is no such requirement about noting what they fail to take out from a natural source. Not to mention being allowed to specify that most evil of ingredients "artificial flavors". The second most evil being "natural flavors.")
Yes! My son who has autism would eat anything we put in front of him until age 3, when his weight, appetite and health suddenly and alarmingly crashed. Ever since that episode, he's had a much more restrictive diet and food preferences. Night and day.
They never successfully identified what happened. Just diagnosed it generally as failure to thrive.
There’s some research on sudden onset autism being treated with antifungals; so at least sometimes a sudden change may be the result of something very specific in the gut.
You seed the gut with nutrients. having lots of fiber and a varied diet increases the number of species that an adult has which is between a couple hundred to a thousand or so.
Our guts are generally dominated by a bunch of beneficial bacteria.
which for many is not the case for a variety of social economic or behavioral reasons. Add in with explosions of bacterial populations due to alcohol or sugar and you can see how we can change our gut biome drastically from week to week.
I’ve noticed I really need to keep alcohol and sugar consumption in check. Sometimes it seems like one drink is enough to kick off a gut ecosystem collapse, and other times my gut is more resistant to the effects. Definitely trying to increase fiber consumption significantly.
How do you know that is a “gut ecosystem collapse” as opposed to hypermotility? Or an overgrowth of the gut ecosystem? Or a problem with the intestinal lining?
Observing that if you eat/drink something specific then you get the shits is valid. Concluding that it is due to a specific mechanism is not valid unless you have something objective like a test supporting that.
It’s like if your train is late and you just conclude that it must be because the steam condenser’s gasket is leaking based on nothing. Maybe true, or maybe the conductor broke his leg, or there is a signaling failure.
If you drop an ACME 100Kg anvil on your foot, you get a broken foot, and you can conclude "this fucked me, I won't do it again". But if you say "I suffered foot ecosystem collapse" and people ask you what that means and how you identified it, whinging about how people should stop asking stupid questions because all bad things are bad therefore they must be the same thing, is not helping anyone.
With IBS-D every meal can result in a loose and unsatisfying stool output! Don't ask me how I know. GLP-1s actually make a hell of a difference for me.
Simple starches and sugars (the former being rapidly converted into the latter) are probably the most harmful ingredient once we exclude actual poisons. And they’re just as normalized with most food being primarily composed of them, even though normal people barely need them.
autists have often a much much stronger need for habits and avoidance of change. This includes a change of, or a less repeting/habitual diet. The effect if applified due to autism being commonly comorbid with ADHD and hyper fixation on specific foods being a very common thing (not (mainly) caused by gut bacteria as the effect is too strong and too specific to be "just" a preference caused by gut bacteria)
but this can lead to a imbalance of gut bacteria and that can have an reinforcing effect on wanting a even more monotonous diet, but in the end this is AFIK "just" a secondary reinforcing reason not the root cause
this relies a bit on a healthy brain to make s good correlation. an unhealthy brain might make a bad diet just out of habit/compulsion rather than driven by their biology.
We usually call these our "safe foods" and yes, it is a very real problem for many of us in the autistic community, specifically around nutritional deficiencies. In a similar vein, as a child I went several years just eating plain Cheerios. For a close friend it was chicken nuggets.
"letting me" is hardly how I'd put it. More like I would refuse to eat any and all food unless committed to a hospital stay. Eating Cheerios and taking supplements was a compromise for my exhausted parents and they were more at a loss of what else to do. I don't think you understand what living with someone with moderate to severe autism is like. It's not being a "willful child" it's an entirely different experience than what most parents are exposed to.
Given how many kids are told to just "shut up and eat it" - and/or didn't have extreme pickiness but got DX'ed perhaps as an adult - I'd say there's a ton of research required to even suggest this as a plausible cause (even for a limited number of cases). It might make things worse, but I highly doubt it's causative.
There is a very popular wrestler who works for WWE who goes by the stage name Triple H. Triple H was part of a group called D Generation X, or DX for short. A clothesline is one of the most basic wrestling moves. This is not sport wrestling, but entertainment wrestling.
> [...] the treatment, which involved a bowel cleanse and daily transplants of fecal microbiota over a period of seven to eight weeks
Maybe I'm misinterpreting what the process of that daily transplant looked like, but I expect they ate a not insignificant amount of hospital food if there were 7-8 weeks of daily treatments.
I didn't realize it was such a protracted process, but even if it's a long series of daily treatment, they aren't going to admit you for that if it can be done outpatient. You will be admitted if it's a risky enough procedure that it requires extended/overnight observation. If you can safely go home and come back the next day that is what they will ask you to do.
Ya, the word "transplants" here seems to mean something very different than you're interpreting it as.
This isn't a hospital procedure like an organ transplant. It's material placed into the recipients colon through an enema, nasogastric tube or possibly even just taking some pills.
So it might range from done at home to done during a 30 minute visit to a clinic.
I know it's nothing on the scale of an organ transplant, but (other than pills) those things would still lead to the patients being at the hospital. And with frequent enough visits to a hospital, you would probably eat at least some meals there. That's all I meant (and said).
In my experience (instant cure for recurrent c. diff) a fecal transplant is easier and simpler than a colonoscopy, which themselves are easy enough to be outpatient.
In a study like this, there’s also a difference in motivation. An AI will mechanically “take the study seriously.” I’m not convinced the doctors will.
But when making decisions about a real patient’s care, a doctor will be operating under different motivations.
They can also refer patients to a specialist, defer a diagnosis until they have more information, use external resources, consult with other doctors.
Doctors aren’t chatbots. They are clinical care directors.
Presuming there are no issues with information leakage, it’s genuinely impressive AI can perform this level of success at a specific doctoring skill. That doesn’t make it a replacement for a doctor. It does make it a useful tool for a doctor or a patient, which is exactly what we’re seeing in practice.
PCR (the chemical reaction) isn’t near optimal, but thermocyclers (the device) are hard to improve on.
For PCR, one of the innovations I’m excited about is the development of PCR that preserves chemical properties of the input DNA, like CG methylation. This is a critical epigenetic mark on cytosines (C DNA bases). When cytosine’s followed by guanine (G base), forming the sequence CG, its complement is also CG. There’s an enzyme called a maintenance methyltransferase that copies CG methylation from the template ssDNA strand to the new reverse strand during DNA replication.
Normally this mark gets diluted into invisibility during PCR, because there’s no maintenance methyltransferase to preserve it as the input DNA is copied. A thermostable maintenance methyltransferase can preserve CG methylation throughout PCR. This is brand new technology that’s just making its way into the scientific marketplace now. It’s the kind of PCR innovation my lab’s excited about.
I just want to point out that there’s a huge difference between thoroughly investigating the family after abuse of this magnitude has been proven, and making parents legally culpable for any harm that comes to their children in general.
We can react to the fact that mothers can do more to protect their children from abuse in many ways. We can give them better access to information and support in getting away from abusers. We can create better links between police and communities they serve. We can create more pathways for children to be exposed to healthy adult behavior and connections with healthy adults, even when the family is dysfunctional.
But when we find evidence that existing supports have failed, deeply investigating why is critical.
The investigators will be able to calculate how many rounds of abuse the victim suffered. The more it happened, the less likely it is the mother was unaware. And if course, the victim can tell us directly whether the mother knew. If so, she deserves a decade of her life in prison as well.
Good design allows systems to work without anyone knowing how the whole thing works.
AI and humans are labor that can be put to work designing and vetting such systems. The problem with AI isn’t that it builds things we don’t understand. It’s that we do not have much experience with its failure modes, limitations and risks. There are many unknown unknowns.
It’s directly analogous to the problem of hiring, management, outsourcing and contacting. Sure, we know that labor can produce massive, highly reliable systems nobody fully understands. But how do we coordinate labor, AI and human, to successfully produce the systems we actually need? What failure modes and advantages does AI introduce into the mix for specific projects?
That’s where the uncertainty comes from, not the lack of comprehensive knowledge of the systems themselves.
Academia is a huge place, and no, its basic function is absolutely not to suck up to power. Every academic I know sees their function as the opposite, even if few take advantage of the limited protections afforded by tenure to speak truth to powers
But Tyler Cowen’s calling in particular is ABSOLUTELY to suck up to power.
I would fully expect that a monotonous diet leads to a heavy skew in the gut microbiome as specific bacterial species that thrive on that diet are selected for, others against. It makes some sense that a fecal transplant could repair the damage. If the diet has shifted or expanded, the transplant could lead to long term benefits by restoring newly-viable bacterial species, perhaps by facilitating digestion of the new types of food.
I’d be curious to see a factoring out of the diet composition, gut microbiome, genetics, and severity of autism symptoms.
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