Social anxiety disorder-associated gut microbiota increases social fear | Hacker News Reader

Social anxiety disorder-associated gut microbiota increases social fear

pnas.org

231 pointsthunderbong147 comments

I know from personal experience that eating sugar does induce more anxiety in me. This might sound weird but I can "physically feel" in my head a certain anxiety when e.g. I think about something awkward. This "physical feel" stopped being there when I stopped eating sweets for a few weeks. One reason why I try to keep my sugar intake down (the other being in danger of getting diabetes...).

Thus, I wholly believe this study.

It's wild how much your gut can mess with your brain chemistry

Can you explain your jump from gut microbiota to sugar? Aside from sugar being one food that passes through our digestion, I'm not certain why you have singled it out.

Just from basic principles, what you eat affects your gut microbiome because different bacteria reproduce more or less from you eating different foods.

I believe most people are not notability adversely affected by sugar and a small subset of the population, like myself, are acutely affected. The former does not invalidate the latter. Sarah Wilson of “I quit sugar” fame started off with a zero sugar crusade then later ameliorated her advice in an apparent effort to generalize her advice for a wider audience. I think advice should be tailored by conditioning on what category a person fits into. I would go further and suggest that a zero sugar diet should also have zero fruit. As a ADHD sugar addict I would generally substitute sugar with fruit and that prevented me from finding out that even my ostensibly healthy diet had too much sugar in it.

do you substitute your fruits with vegetables? Maybe I should try it as well but then again my daily apple is one of my highlights.

The most direct substitution was cheese, lactose does not appear to have the same effect on me as fructose or sucrose.

I mostly eat kale for vegetables, this also helps with subclinical insulin resistance and inflammation. I think roasting vegetables may end up being too sweet.

I did an extended 5 day water fast to kick start the microbiome changes I undertook it as an experiment and the effectiveness in lifting brain fog suggested that it likely had a microbiome component.

i thought most cheese has way less lactose, if any, than milk?

Really depends on the cheese. Most has less than milk but for some like cottage cheese it's still pretty high. Other hard cheeses like parmesan it's basically zero.

You could use a rule of thumb that hard/aged cheeses are low lactose. But there's outliers like brie/camembert that are very low lactose even when relatively fresh.

Would you mind citing which kind of cheese you eat? Because much cheese has little to no lactose, and also goat lactose does not necessarily have the same effect as cow lactose. Finally, the fats and proteins in cheese affect digestion and possibly sugar absorption.

Honestly when battling sugar cravings it would be rather large chunks of parmesan cheese because I find it rather sweet. I assumed that was due to lactose but perhaps I'm wrong about that. It could also be that even a small amount of lactose tastes sweet after a while of not eating sugar.

Parmesan has close to zero lactose. However, it has an extremely high level of free glutamate, up to 1.6%, which is why it tastes delicious and makes other food taste delicious. Probably should avoid it, along with MSG, if you have blood pressure issues. Probably fine otherwise.

I do drink a lot of milk so I do know I'm not lactose intolerant so my prior assumption was that cheese wouldn't bother me either. I didn't know that hard cheese had so little lactose and I'm happy to be corrected. The parmesan cheese was thankfully just a transition phase that I was able to stop.

> Lactose is a disaccharide composed of galactose and glucose and has the molecular formula C₁₂H₂₂O₁₁.

What could be different?

Do you mean that relative amount of lactose? I believe it's that's not different in the raw material.[0]

[0] https://www.canr.msu.edu/news/goat-milk-versus-cow-milk-a-co...

It is important to note that extended water fasting will have adverse effects for some people. It is not recommended to do it for that long.

"" The water fast lasts for 24–72 hours. You should not water fast for longer than this without medical supervision because of health risks. "" https://www.healthline.com/nutrition/water-fasting

Thank you, I initially came here to post a comment disencouraging sugar based on my anecdotal experience. It's indeed weird that people I know don't report the same immediate, acute, negative effects that I experience upon sugar consumption. Until now it never occurred to me my experience might not be universal. Curiously I have ADHD too. Maybe there is a link?

In my experience an apple = a bar of chocolate, has the exact same effect, no difference except maybe a bar of chocolate is slightly faster acting. Immediate brain fog, almost like being psuedo-drunk.

I too gave up on fruits after deluding myself for a long time that an apple a day is somehow healthy for me. In hindsight it's crystal clear addiction. I was looking forward the entire day to that moment where I'd 'allow' myself the fruit. I was frequently unable to stop eating after the determined portion.

Sure, I absolutely think there is a ADHD link and I think there is a likely (which is not the same as definitely) common cause of hypermobile Ehlers Danlos Syndrome (hEDS), understand that this is not the medical establishment view but I think my models are more accurate and more predictive.

If you scroll through my previous message history I cover this topic quite a bit, you can also email me. In general terms, I think hEDS is far more common than doctors do, and is likely caused by TNXB SNPs. TNXB SPNs are overlooked because these are too common to cause the 'rare' condition - but if you drop the prior assumption of rarity then a very different picture is painted. It appears to me that the only difference between hEDS and far more common Generalized Joint Hypermobility (GJH) is severity and the stochastic diagnosis that this difference causes. The prior assumption of rarity has informed the diagnostic test so the diagnostic tests reproduce this assumption and in my view have an extremely high false negative rate. If using other proxy stats like the rate of hypermobility in Long Covid from the work of Dr Jessica Eccles it's pretty clear that that prior assumption of rarity is wildly inaccurate. I was able to figure this out because I have experience as an applied researcher and machine learning, having spent half a lifetime reading papers I've developed a bit of a nose for the sorts of mistakes that academic researchers tend to make.

You say sugar, but are you referring to glucose or fructose?

There is a meaningful amount of scientific literature connecting fructose and inflammation.

The AVERAGE human can only digest about 30g of fructose a day. Some substantially more, some substantially less.

A can of soda or three apples is about 30g of fructose.

Inflammation (high- and low grade)then being a second step linking to anxiety.

I am talking about the sugar in sweets. My daily apple does not appear to heighten my anxiety.

I have heard people say that eating fibers together with fructose(like when eating a apple) reduces the impact of fructose, as fibers create a lining on the gut wall reducing the absorption rate.

Sounds reasonable. But i have had a hard time finding evidence verifying that hypotesis.

i'm pretty sure this saying is well agreed upon by the mainstream medical community. (not a medical pro myself, but follow a lot of articles and podcasts from mainstream sources)

Its in most nutrition textbooks, it's partly why fiber is so important.

Eating fiber with any carbohydrates reduces the absorption rate. It's partly why eating an Apple is better for you than eating a lolly despite both being high in sugar.

I think you have to look for "glycemic index" and learn about its mechanisms, which in your defense is not an obvious term to search for.

I’m not sure about that mechanism, but the impact on blood sugar is quantified as “glycemic index” and “glycemic load.”

Serotonigenic microbes digest fiber into feelgood neurotransmitters.

You're welcome.

Athletes consume 50g of fructose (and 50g of glucose) per hour. It's actually fairly easy to train yourself to this level.

> Athletes consume 50g of fructose (and 50g of glucose) per hour

...while actively competing in endurance events. They don't do this while sitting on the couch in the evening. And it's very specifically only endurance trained athletes who do this, sprinters would never need to consume that much sugar.

It's a valid point though, a sugary snack or sports drink directly before hitting the gym for a hard workout session is probably fine, as long as your blood wasn't already saturated with glucose from earlier sugary foods, and as long as you don't have insulin resistance.

Sure, but that all has nothing to do with digestion, that has to do with blood sugar levels and what your body does with the energy afterwards. Digesting 30g of fructose per day is not any kind of biological limit, in contrast to what GGP claimed.

It's a biological limit without long term health effects, unless you're burning it off with intense exercise.

Heads up, I don’t think there’s a link between eating sugar and risk of developing diabetes. Obesity is a risk factor but not sugar itself.

Maybe. But eating sweets makes me eat more anyway. Which leads to me gaining weight. So it's the same anyhow.

https://www.sciencedirect.com/science/article/pii/S216183132...

There's a complicated relationship, according to this meta-analysis. Eating sugar in isolation from other sources of nutrition is a risk factor. Eating fruit, or eating sweetened foods with redeeming qualities like yoghurt and wholegrain cereal, is probably inversely correlated (with lower confidence). These seem to be true even when controlling for BMI.

Looking at the meta-analysis, it's hard to say there's no link. The authors suggest that fibre might mitigate the impact, and that adding sugar to otherwise healthy foods might encourage higher consumption of them.

I recently started consuming relatively large amounts of fiber (standard daily dose of whole psyllium husks mixed with water) and I feel noticeably less anxious than on days when I don't take it. Fiber has been shown to interact somehow (I'm not super familiar) with the body's insulin levels. I wonder if it is related to what TFA is saying.

I get a similar feeling when drinking milk. Maybe I'm becoming intolerant.

Sugar? Why not caffeine?

I swear that a 4+ week coffee and caffeinated holiday improved emotional regulation and turns down OCD behaviours and anxiety.

Not sure if this is microbiota-related or related to down-regulation of neuroreceptors activated by coffee compounds.

I’ve heard arguments such as “well… caffeine is cleared within hours so a weeks-long effect is placebo”. Say what you want.

Well I don't think they're saying that wouldn't happen with caffeine, just that this is their experience with sugar.

Yes same, my anxiety is completely gone on keto. It’s just really hard to constantly be in keto, so I limit my carbs which helps but isn’t quite the same

Most of my adult life I've suffered from DPDR. In recent years I've been able to get somewhat of a handle on it.

While I never pinned down the cause exactly, my talk therapist and I came to the realization that some meals would trigger it. Usually those meals were obviously bad for my health, so I started avoiding them.

> This might sound weird but I can "physically feel" in my head a certain anxiety

Why I commented. DPDR is in the same box as anxiety and, yeah, I could literally feel this weird pressure in my head. An actual physical sensation. Seems like we had different cause and side effects but it's so good to read there's someone else out there.

Glad you found something that worked for you. There's so much we don't know about our bodies.

---

[0] https://en.wikipedia.org/wiki/Depersonalization-derealizatio...

Thank you for posting. You made my day as well :)

I think it makes sense that our microbiome should be able to trigger such a response. If your microbiome is changing, it means that some microbe is gaining numbers it didn't previously have, and your current bodily functions, such as your immune system, aren't stopping it. That doesn't necessarily mean your immune system is compromised, but if it is then it would probably be good not to spend a lot of time around other individuals, especially large groups or strangers. Other reasons for your microbiome to be shifting, like a sudden change in diet or enviroment, could also be indicative of an issue like food shortages or territorial change where it would also be good to minimize your exposure to and reliance on others. Finally, depending on what exactly is gaining a foothold, you could potentially be a threat to your kin if you come around them. Developing a social fear response to certain changes in gut microbiome could thus be quite beneficial for most social creatures.

Beneficial for the group, not the individual, I suppose.

Which is to say, maladaptive. Despite all the people wishing evolution worked at the group level, it doesn't. Groups don't have offspring, individuals do, and thus things that are bad for the individual are extinguished regardless of their effect on the group.

If you look closely enough, even individuals aren't the true units of evolution, for the same reason; competing alleles is where the real action is.

Alleles are shared with kin which gives rise to multilevel selection effects in rare but real scenarios.

When thinking about evolutionary forces, you cannot conflate "positive" outcome with survival and reproduction. An individual might survive and produce offspring via effects that make the individual unhappy in their own life and/or with shortened life.

It's only when an effect causes death or infertility prior to normal reproductive phases that we can really say it has a direct evolutionary pressure. Anything that happens later is always going to be through secondary, social effects on how their condition supports or hinders their offspring from reproducing further generations.

Voting me down doesn't change the fact that group selection is a myth. A myth that some people are fervently attached to, but a myth nonetheless. Groups simply don't reproduce at a rate or fidelity to allow evolution at the group level over the time scales in question.

E pur si muove.

How is it not beneficial for the individual to avoid threats to their health and safety?

I mean the individual who is sick is now sent into a downward spiral of anxiety and frustration instead of evolution helping them (e.g. by making others take care of them, etc.)

The problem with Evolutionary Psychology is that it’s easy to construct this sort of “just so” story for pretty much any causal link, and they are not falsifiable.

IMO the simpler hypothesis here is that this isn’t anything adaptive, it’s just another example of how biology is like spaghetti code; changing one chemical signal will affect an essentially random set of downstream systems, some of which can be causally connected to psychology/behavior.

Which would still be natural selection though.

That isn't a problem because no one speaks of these suppositions in terms of "just so" but in terms of "could be due to." If you want to prove something as just so you have to do a lot more work describing a mechanism of action and that involves reaching into a different toolbox.

Could also be like climate change, where it correctly describes a broad phenomenon, but cannot be used to identify or classify any individual event. E.g., Wildfires are probably getting worse because of climate change, but it's difficult to say if the Pacific Palisades fire would not have happened in a cooler global climate.

So, is microbiome-mediated social anxiety selected for as an advantageous trait for societies subject to communicable diseases and the travails of nomadism? Maybe. Did YOUR microbiome-mediated social anxiety arise because it was advantageous for your community? Probably impossible to say.

Also, a hole in GP's logic: you would expect protective social anxiety to arise in people whose situation hasn't much changed except that they've encountered people whose has (as with sedentary villagers encountering nomads who may or may not be about to ransack their settlement).

Wildfires are worse in areas where the wrong type of trees were planted as well which is common in logging areas or places cheaply "reforested" that don't do much research on what should be growing there. Wildfires themselves aren't bad per say either as certain trees only grow from fires. Not to say that climate change isn't a factor though, but there are a lot of varibles too.

> you would expect protective social anxiety to arise in people whose situation hasn't much changed except that they've encountered people whose has (as with sedentary villagers encountering nomads who may or may not be about to ransack their settlement).

No, you would not expect that. If rats that self-isolate when their gut micro-biomes change avoid diseases that other rats get afflicted with, then evolution will lead to the mechanism spreading through the rats over time. The rats do not need to know why self-isolating helps, they do not need to even know that self-isolating helps, and they do not need to be in the position where it would help the most.

GP's hypothesis is that diet/environment microbiome changes induce a protective social anxiety. However, a nomadic population - the most likely to exhibit those changes - are successful when exhibiting prosocial or confrontational characteristics, the opposite of social anxiety. Social anxiety is most protective for sedentary groups, who probably should be suspicious of outsiders.

Nothing you said contradicts this, and I'm not sure how to square the circle, even though microbiome-mediated behavior as an explanation for broad, otherwise irrational behavior patterns is attractive.

> IMO the simpler hypothesis here is that this isn’t anything adaptive, it’s just another example of how biology is like spaghetti code; changing one chemical signal will affect an essentially random set of downstream systems, some of which can be causally connected to psychology/behavior.

That's not a competing hypothesis. Obviously the change to the gut affects other things, some of which happen to impact psychology and behavior.

The question is why does this particular change to gut microbiome have such a similar impact on two different species that diverged many tens of millions of years ago? "It just does" is not a very satisfying answer.

Makes me wonder how many other "maladaptive" responses today actually had adaptive roots in a different context

I've seen probiotic supplements that have strains that claim to help with anxiety and depression, but I've never really looked into them because I'm quite skeptical they do anything. But if anyone is familiar with them and has any feedback I'd be interested to hear it.

Strongly second this ask.

So long as it isn’t eating the variety of fresh fruits and vegetables that produce gut serotonin in the microbial breakdown of complex carbohydrates and fiber, right?

Eating fresh fruits and veggies is a great general health advice but unlikely to shift your gut microbiome meaningfully (unless you are eating some specific fruits or fruit skins in specific conditions).

And randomly eating healthy stuff is probably not going to shift your biome in a particular direction nor eliminate the cause of biome issues.

I eat healthy including a lot of whole fruit, nuts, dried fruits, dark green veggies and grass finished meats and there are still times I have my biome be a bit off.

“Unlikely”, “randomly”, and “probably” had me nervous about your contribution to this discussion.

I do appreciate the quantitative precision at the end of your last sentence.

Why wouldn’t it be? Do you know which ones exhibit the desired characteristic?

The ones that aren’t food shaped name brand products or fruit colored sugar water.

I’m fairly certain that is not accurate given I was vegetarian for over a decade.

Whether or not the effect in the paper turns out to be true and reproducible, the supplements you've seen almost certainly don't do anything unless you're wiping out your established gut microbiota with antibiotics first. Your existing microbiota are entrenched and in a very good position to defend themselves from any weakened intruders you might intentionally introduce. Meanwhile, supplement companies really like to make exaggerated claims.

I posted some links to papers I came across here: https://news.ycombinator.com/item?id=44284165

It's a very fair and valid question as to whether a probiotic supplement:

A) Survives being packaged and stored in a warehouse for an indeterminate amount of time B) Being shipped in the back of a truck/airplane C) If the bacteria is still alive whether it can make it through the GI tract to even have any effect whatsoever

I don't know whether this has been studied. I know Consumer Labs does yearly tests on various supplements, probiotics included, but it's a subscription service and you need to subscribe to see the results. I have subscribed to them in the past and found their testing and articles quite helpful. I

In their tests, ConsumerLab found that the number of viable cells in probiotic products ranged from 1 million to 225 billion per recommended serving.

Additionally, some products were contaminated with harmful bacteria, such as Pseudomonas aeruginosa, which poses a risk to immunocompromised individuals and infants.

The company also noted that the enteric coating of some products did not function properly, potentially affecting the delivery of the probiotics to the gut. (Brave AI Search summary of the article below) [1]

ConsumerLab Tests Reveal Best Probiotic Supplements and Those With Quality Issues https://www.consumerlab.com/news/best-probiotic-supplements/...

> Whether or not the effect in the paper turns out to be true and reproducible, the supplements you've seen almost certainly don't do anything unless you're wiping out your established gut microbiota with antibiotics first. Your existing microbiota are entrenched and in a very good position to defend themselves from any weakened intruders you might intentionally introduce.

There is an ton of probiotic research that shows probiotics can survive transit to the gut and reproduce there.

Even without probiotic supplmentaion, you microbiome absolutely can and will change over time.

I've had a LOT of gut problems in my life. I have a physically broken stomach, have had to have stomach surgery in the past, and probably will have to do it again soon.

Most probiotics I've taken did nothing. The only ones that seem to actually work for me are these: https://drohhiraprobiotics.com/

Not sure why it works, but anecdotally, they do.

Other things that have helped significantly – cutting out alcohol.

I'm not sure how many probiotics will make it through the stomach acid. One would think suppository would be vastly more effective: parachute directly onto the battlefield.

yeah I had serious gut problems for years and no probiotic ever did the slightest thing. Anecdotally I can’t differentiate them from snake oil.

But Metamucil changed my life dramatically over a span of a few weeks. Never had the type of symptoms it’s indicated for, which everyone I mention it to just assumes. But it fixed me somehow.

I was recently talking about fiber & fiber supplements on here in a thread about a new type of fiber that was shown in a study to help with weight loss.

Acetylated cellulose suppresses mass through commensals consuming carbohydrates https://news.ycombinator.com/item?id=44219171

Fermented foods are way more helpful IME. I've even found kombucha protective against mildly spoiled food.

I can also attest to having my first alcoholic drink in a while and it screwing me up for a week.

I've always been skeptical of probiotic supplements in general mostly because they are stored/shipped in unrefrigerated environments. I believe in most cases the bacteria would end up dead before you even ingested it. However, some companies have developed strains that can withstand some amount of heat. But you never know where they've been stored/for how long/etc.

I remember speaking to someone who had the suggestion to try fermenting food with probiotic supplements, as that would be the only realistic way to know if they were still alive.

There are vendors that do sell probiotic supplements that come shipped in dry ice that people with Crohn's disease & other GI ailments. I don't remember the name of the company that sold them though.

But, I agree that yogurt or saurkraut/kimchi and other fermented products would be a good way to get some gut bacteria. Those would be great to use after you came off antibiotics, but it wouldn't necessarily help with genital mental health/anxiety (as far as I'm aware).

Interestingly, yeast has neurotransmitters and neurotransmitter precursors in it such as tryptophan and serotonin. [1]

Having said all that, I decided to look up the "mood enhancing" probiotic strains I've seen being sold in OTC supplements. The two strains I see are Lactobacillus helveticus Rosell-52 and Bifidobacterium longum Rosell-175 (there may be others I'm unaware of). The studies are quite small, unfortunately. (I didn't read all of them though) [2] [3] [4] [5].

Finally, this is quite a unique term I haven't come across: Psychobiotics!

Psychobiotics are probiotics that have the characteristics of modulating central nervous system (CNS) functions or reconciled actions by the gut–brain axis (GBA) through neural, humoral and metabolic pathways to improve gastrointestinal activity as well as anxiolytic and even antidepressant abilities. [6]

[1] Melatonin and Other Tryptophan Metabolites Produced by Yeasts: Implications in Cardiovascular and Neurodegenerative Diseases https://pmc.ncbi.nlm.nih.gov/articles/PMC4718080/

[2] Assessment of psychotropic-like properties of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in rats and human subjects https://pubmed.ncbi.nlm.nih.gov/20974015/

[3] Probiotics Promising for Mild to Moderate Depression https://www.medscape.com/viewarticle/881877

[4] The effect of Lactobacillus helveticus fermented milk on sleep and health perception in elderly subjects https://pubmed.ncbi.nlm.nih.gov/17851460/

[5] One Giant Leap from Mouse to Man: The Microbiota–Gut–Brain Axis in Mood Disorders and Translational Challenges Moving towards Human Clinical Trials https://pmc.ncbi.nlm.nih.gov/articles/PMC8840472/

[6] Exploring the Potential of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 as Promising Psychobiotics Using SHIME https://pmc.ncbi.nlm.nih.gov/articles/PMC10056475/

> I've always been skeptical of probiotic supplements in general mostly because they are stored/shipped in unrefrigerated environments. I believe in most cases the bacteria would end up dead before you even ingested it. However, some companies have developed strains that can withstand some amount of heat. But you never know where they've been stored/for how long/etc.

Probiotics in pill/capsule form are generally freeze dried, so they are much less temperature sensitive than live bacteria.

One doctor recommended this brand to me too not long ago, but I'm a bit worried that this probiotic contains histamine-producing bacteria since I have some histamine sensitivity.

And overall I'm a bit hesitant about consuming too many strains at once.

So far I've been having success with S. boulardii CNCM I-745 (which is actually a probiotic yeast) and I'm trying out L. rhamnosus GG.

Bifidobacterium infantis 35624 also looks interesting.

After trying a lot of things what worked for me was cutting out negative food; usually gluten, lactose, fructose. Probiotics never did anything for me.

What makes gluten a negative food? (outside of being coeliac)

Nothing specific, simply your own stomach. Every human is different. Some people can eat spicy foods, some people can't. Best strategy is to learn for yourself what make you happy when you wake up and what makes you feel bad. Listen to your own body, make changes.

Thanks for clarifying. I agree with your answer. Do what works for you!

Since the advent of "gluten free" foods, specifically for coeliacs, the fact foods get advertised as "X free" leads a percentage of the population to believe that X is therefore bad and should be avoided for as-a-general-rule health reasons rather than health reasons limited to those who get complications as a result of X.

There's this one person who claims to have found out that theses probiotics need to be amplified into a megadose, and subsequently they cured themselves from social anxiety. I'm not sure if there are other people who have replicated, but the initial report seems trustworthy. See https://pdfcoffee.com/experimental-treatment-for-social-phob...

That's very interesting. Making your own yogurt sounds like it could be easy to do and you could potentially just use OTC probiotic capsules or powder.

I posted some studies above about two probiotic strains that have specifically been studied for mood enhancement aka "psychobiotics": Lactobacillus helveticus Rosell-52 and Bifidobacterium longum Rosell-175.

I’ve seen people who seem to know what they’re talking about cast doubt that you could create your own probiotic yogurt in a typical kitchen since other strains are likely to dominate without a sterile environment and careful methods.

The strain you want has a huge headstart, and there shouldn't be much bacteria in boiled milk to begin with. Containers can be also sterilized with boiling water. Then keep it cool after it's done (14 hours). It doesn't seem likely that some other strain would dominate, but who knows.

Aside from the other red flags in that link, the author claims to be able to get rid of SAD symptoms in "about 45 minutes" which strongly suggests a placebo effect to me (or at least not an effect from changes in their microbiome).

Yeah, that's odd for sure.

This is only anecdotal, but probiotic supplements absolutely had a large impact on my social anxiety. I can't remember for the life of me where I heard it, but I specifically looked for ones that with strains were "dirt-based" - PB-8 is the one I currently take. Looking back, I realized just how directly getting anxious was tied to having an upset stomach for me. The first week or so was a bit rough, but after that it's been smooth sailing. The supplements are so cheap that I think it's worth trying for a bit. Kombucha/other fermented foods may also have a positive impact.

Caveat: I have never been diagnosed with an anxiety disorder, so things may different in that case.

Was your anxiety caused by your upset stomach you think? Or was it unrelated?

This is gonna go viral as: just eat more yogurt to stop being awkward or whatever.

Yoghurts probably won't help, but Fecal Microbiota Transplantation might.

A team at the University of Calgary is currently recruiting participants with Major Depressive Disorder and Obsessive-Compulsive Disorder:

https://research.ucalgary.ca/participate/clinical-trial-eval...

https://research.ucalgary.ca/participate/focused-study-fmt-o...

Damn, that's my city and I have been struggling with some other stuff

I don't fall under the umbrella of Major Depressive or OCD but if they were doing trials to help anxiety or something I would probably sign up

Eat more poop?

You have to boof the poo for it to work right.

The experiment looked to be the other way around. If you introduced new microbiota from patients with SAD this caused SAD in mice.

So introducing new microbiota won’t solve the problem. The theory that needs to be tested is that we know microbiota can switch SAD on, but does removal of said microbiota turn it off? It needs to be an antibiotic cleansing. It can even be DIY. People can try this on themselves. I think the unknown factor here though is whether or not a persons diet is introducing the SAD causing microbiota.

Do we get gut bacteria from the people around us? Where does a newborn get their gut bacteria from?

The entry point to the gut is from the mouth so because of that, I think food is where most of the gut bacteria comes from.

Sure, as long as you hold your mouth and nose closed when not eating.

You have a back door as well for the gut that tends to open at least once a day. We know fecal matter is in the air in most bathrooms. It wouldn't surprise me if you got an infusion of community fecal biome right into your anus every time you used a restroom that isn't your own.

Yes but usually when the back door opens things are exiting the gut rather then going in. So I don’t think that counts.

There are cases where things do enter the back door but I think that’s just humans getting creative and it wasn’t designed for entry.

Its not like there is positive air flow keeping any microbes in the air out and away. If something lands on there it can probably colonize then spread to the inside slipping through the sphincter.

we can from kissing

It's not just food as many commenters are pointing out. It could be from what people are drinking, even water, if oral delivery is not sanitized.

So if the choice is between unsanitary water or sterile and containing chlorine, etc., which has the effect of strengthening the microbiota so that the resulting population increases perceived wellness in the host organism’s sociopolitical fitness, its simple enough, we all stop eating and drinking for ultimate safety and maximum paperclips.

Chlorine is not the only way to sterilize water. Ultraviolet sterilization is a chemical-free option suitable for many use cases: https://en.m.wikipedia.org/wiki/Ultraviolet_germicidal_irrad...

Newborns get a lot from their mother. They have very little stomach acid, so whatever they are getting goes straight through to their gut.

Heh, if so, I wonder if there is a correlation between social anxiety and babies who relied on formula instead of breastfeeding.

Introducing new microbiota will put competitive pressure on the old one, so I wouldn't write it off with out trying.

Lotta yogurts people buy are chock full of added sugars.

Eating more prebiotics in the form of unprocessed plants is much more effective at improving gut health than probiotic supplements or even probiotic foods. (Of course you can do both.)

I’m writing the following in jest, before anyone takes this seriously, as I assume this kind of correlation has been accounted for.

Maybe the causation is reversed: people who go out more are more frequently infected with all kinds of bugs, from getting too intimate with strangers to eating stuff that was prepared by someone not too assiduous in their hand washing - a sibling reply mentioning fecal microbiota transplant comes to mind

I know this article is about bugs that cause anxiety, but maybe they just lose the competition in a gut environment with the social bugs

People who stay at home are less infected, thus the correlation with these gut specimens

It's an interesting theory! Maybe find some extroverts and share meals with them & do some consensual saliva exchange with them and pick up their healthy bacteria! :)

I've suffered with social anxiety for a very long time. Thirty years ago a doctor prescribed a MAOI which immediately transformed me into a social butterfly (which in hindsight was a very difficult transition). This forever proved to me what the doctor had told me: it is all about chemical balance in the brain.

The problem, of course, was the danger. I could die within minutes if I ate fermented food without taking the antidote I always carried. Problem with that was the risk was almost the same if I took the antidote if it wasn't needed.

I therefore only stayed on the meds for maybe 6 months (during which time I went from 150lbs to 225lbs).

I've never found an alternative substitute. I've taken meds that help lessen the anxiety, but never found anything else that literally changed who I was (making me an incredibly social person).

PS: I think it was Nardil. I wasn't having any issues with depression. The doctor was specializing social anxiety and in particular in the use of Nardil to help. He also told me that the chemical balance in my brain indicated that, without Nardil, I would almost certainly become a hermit in my 70s. I'm 72 and his prognosis was spot on.

That's quite interesting. In my experience, I've suffered from severe anxiety and depression my entire adult life. I spent years working with a psychiatrist trying every SSRI on the market. None of them seemed to help in the slightest, until I asked to try Eldepryl (selegiline), an MAO-B. It helps greatly with depression, but hasn't helped with anxiety. An MAO-B has the advantage of not having any issue with tyramine (the cheese effect) that you're referring to.

I've never heard of Nardil, but I'll have to look into it.

I am always cautious about offering any kind of medical suggestions online. Please take this with a grain of salt:

I struggled with anxiety and depression, treated with anti-depressants and such

After years of that, a doctor suggested I test for ADHD and I got medicated for that after the test was positive

After being medicated for ADHD, I had much less anxiety and basically no depression. Turns out that both Anxiety and Depression are potentially comorbid with unmedicated ADHD

It might be worth asking about. It could be that you need stimulants, not antidepressants

I hear this often and am curious about it, as someone with an ADHD-PI diagnosis who has taken nearly every med, ranging from Ritalin, Adderall, Vyvanse, Dexedrine, to Strattera and possibly others I can't recall over the past 20 years. I've never felt like any of them had any lasting effect on my anxiety or depression. They all give a temporary relief of some of these symptoms while the drug is in my system, but I always return to baseline, which results in a roller coaster effect. Strattera may have been the exception because its not a stimulant like the others but ultimately it didn't address issues with motivation so I stopped it. I would love something that successfully addressed ADHD+anxiety+depression. And yes, I exercise, get 8 hours of sleep on average, eat pretty good, and don't live a stressful live.

> They all give a temporary relief of some of these symptoms while the drug is in my system, but I always return to baseline, which results in a roller coaster effect

I'm sorry, I'm not any kind of medical expert so I can't really say anything useful here

If I did have to guess, I would say that Anxiety, Depression, or all sorts of other things can stand on their own, or be a comorbid symptom caused by something else

In my case it seems like my Anxiety and Depression were at least somewhat caused by my underlying ADHD. Treating ADHD helped me with the anxiety and depression at the same time

But just because it can be this way doesn't mean it has to be. It could be there is something else underlying your other symptoms. Or they just aren't comorbid and need separate treatment

I don't know. I'm sorry to hear you still have some trouble with things though. I hope you keep going and figure them out

You didn't mention therapy in your comment. Was this something you tried? Personally I've went from hermit > normally social thanks to CBT. It's very hard work, you need to find the right therapist, and you have to continually work on it but it gets easier.

Anxiety is not identical to depression, but consider: "The Chemical Imbalance Theory of Depression: Where Is It Going?" https://www.madinamerica.com/2020/02/chemical-imbalance-theo... "The spurious chemical imbalance theory of depression is arguably the most destructive thing that psychiatry has ever done. ..."

The placebo effect can be very real...

And self-fulfilling predictions by authority figures can also be powerful...

Lack of neurotransmitters being produced in the gut due to microbiome issues is maybe the closest to a real "imbalance" -- like with the original article. Example: "How Your Gut Health Affects Your Brain: The Mind-Altering Power of Your Microbiome" https://www.sciencenewstoday.org/how-your-gut-health-affects... "Your gut microbes can produce neurotransmitters like serotonin, dopamine, gamma-aminobutyric acid (GABA), and acetylcholine—all of which are crucial for brain function. In fact, more than 90% of the body’s serotonin is produced in the gut, not the brain. This has profound implications for mood and emotional health."

Lots more health and wellness ideas collected by me here: https://github.com/pdfernhout/High-Performance-Organizations...

Good luck finding things that work for you -- assuming you are not happy just the way you are. "I like you just the way you are" - Mr. Rodgers https://www.youtube.com/watch?v=kPDTpqtmzPQ

This is well known in low carb and juice fasting communities: many people completely healed life long depression after an extreme dietary change.

I feel all such studies should be headlined with: In mice: blah blah blah.

and then if the research is farther along:

In <other animal>: blah blah

and finally if ever

In humans: blah blah blah.

I keep reading storie about what happens to mice in studies but I am far more interested when the research has been able to get to human trials and results are coming in.

Seems like a never-ending cycle for some. You eat sugar and it messes with your brain, then you eat more sugar because your brain is messed up.

I've experienced social anxiety myself and always thought it was just part of who I am. Seeing that gut microbiota might influence something as specific as social fear and that it can even trigger it in mice is honestly a bit unsettling.

I'm really curious whether this kind of research could lead to something beyond the usual therapy or medication. It would be amazing to see new treatments emerge that are based on the microbiome.

16S sequencing doesn't reveal a mechanism, it indicates a narrow genomic pattern that may or may not be relevant.

I kinda skimmed parts of it but a question I have is whether the study was appropriately blinded. ctrl-f blind didn't give any results. One of my biggest concerns with gut flora research is wishful thinking.

It's interesting, if we assume that the microbiota "wants" something (like other viruses or bacteria trying to affect the host in some way) and learned it evolutionary then when inside a human it tends to avoid other humans probably due to some disadvantages of the contacts for them. But why? It looks a little strange because humans are highly social species to the edge of survivability so the microbiota just risks losing the host completely.

They caused SAD in mice by introducing specific microbiota.

But does the system have hysteresis? Can the flip be switched the other way? Introduce antibiotics to wipe out all the microbiota and does the SAD improve?

There can be human trials for this given that antibiotics are approved low risk medicines. Clinical trials with antibiotics to clean out and reset the microbiome along with strict diets in attempt to prevent reintroduction of said microbiota.

It can even be DIY.

My social anxiety sky rocketed at 19 and didn't start to settle down until 23/24. I never knew exactly why, and that's always troubled me a bit. A microbe population getting out of hand sounds possible, as my diet and surroundings changed drastically at 19. Interesting stuff.

>> surroundings changed drastically at 19

Couldn't this be the easier explanation? People at that age tend to move away from home, go to college or start work - all big changes, all highly social and potentially stressful changes. Mental health issues leading on from this is understandable and anecdotally I've saw it in several friends.

People who grew up in a certain SES class (of their parents) also tend to take on poverty-conditions when in college (oh man all I can afford this week are these cup noodles), and not to mention frequent destruction of the microbiome with alcohol. It's probably very disrupting. Maybe has something to do with why those who have a predisposition to having a psychotic break tend to have their first around 20.

Yeah, the brain might not be the only place we should be looking when it comes to mental health.

Scientists think of the gut as our second brain or perhaps an extension of our brain.

I suspect that this is a compounding effect of two stressors. The mice with a healthy microbiota can handle the social stress, but when you combine both the social stress and disordered gut, the heightened sensitivity is observed.

Is that why it feels like anxiety comes from the gut?

Have anxiety. Got sick when working for FAANG. Had to take disability as a result.

Your guts are VERY tied to your brain, and your gut biome WILL change if you are stressed enough. When your biome goes off, LOTS of bad things can happen to you.

I was in constant pain and had IBS-C for two years until I learned how to manage by stress. But it came at a terrible cost of having to flounder a bunch of opportunities as a result.

If you have lower-left gut pain, talk to your doctor, but for me it was all stress and anxiety.

Can we just keep taking courses of scorched earth antibiotics until we come up with a microbiome combo that feels good?

Anecdotally, that generally seems to make things worse, not better.

Where does having solid stool sit in comparison to not having social anxiety?

I did this years ago and it seemed to work, but n=1. It took two cycles of antibiotics and intentional introduction of "good bacteria" before I landed on something that seemed to fix most of my food intolerances. Didn't seem to have any impact on anxiety.

I learned later that this is pretty dangerous to attempt, since you're very likely to give yourself c diff or some other infection and end up with persistent IBS before you land on a good microbiome.

Given that it'll cure the latent chlamydia and gonorrhea that people have - not to mention the cat toxiplasmos - lets do it!

oh yea fore sure but I have just given up on life. I have my job and apartment and I will rot here.

(2023)

this astonishes me

Offtopic but can we please stop and appreciate the excellent acronym "SAD"? It's gotta be right up there with hippopotomonstrosesquippedaliophobia in the gallery of best disease names.

It also stands for Standard American Diet. So there you go.

It also stands for Seasonal Affective Disorder which is winter depression.

I’ve dealt with social anxiety myself and always thought it was just part of my personality. This study really surprised me. Transplanting gut microbiota from SAD patients made mice more socially anxious too.

If future treatments can target the gut instead of relying only on willpower or medication, that might be a gentler and more effective path.

Makes sense. People naturally want to poop someplace comfortable because pooping is a very vulnerable position for a human.

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