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Modern city dwellers have lost about half their gut microbes

398 points by Hooke 4y ago

bmj 4y ago
Requisite xkcd: https://xkcd.com/1471/ https://xkcd.com/1471/
Sunspark 4y ago
Once a gene has started expressing, it's pretty hard to flip the switch back to the off position. Losing the microbes is a big problem. It's just going to get worse. People seem to have this fetish for anti-bacterial everything.. soaps, coatings, etc. They take anti-biotics even for viral issues then they wonder why they start developing a new health problem they didn't have before, like a mood disorder or an autoimmune issue.
- olliej 4y ago
  What did the lost microbes do? If they helped digest things that aren't part of our diet then the there would be no selective pressure maintaining them, so they could be easily dropped, independent of the issues of vast over-application of antibiotics, etc. Over application of antibiotics and anti-bacterial stuff is clearly causing problems, but that's not the only thing that is happening that impacts something as complex as the gut. Just as with genes, the microbiome is under constant selective pressure from evolution, and we will - over time - gain new microbes as we lose ones that aren't beneficial.
- thelittleone 4y ago
  Here in Indonesia, antibiotics can be bought over the counter without a prescription. Many people self medicate for a cough or runny nose (they don't distinguish whether viral or bacterial, most likely the average worker doesn't know the difference). Few have the luxury to take a sick day so the pressure is on.
  - Sunspark 4y ago
    This should be an election issue, that Indonesia should not be selling antibiotics without a prescription. Stupid people take them just a little then stop, and as a result are continually training tuberclosis and other bacteria to become antibiotic resistant. Then when they can't treat things anymore, surprised Indonesian faces all around. What if the West doesn't have anything new for them? Time to die. Before antibiotics, was not a fun time and we're heading back there soon.
olliej 4y ago
My first thoughts are (without access to the actual article) * We have lost the microbiome that primates present * have we gained other microbes? * what did those microbes we lost do? If they break down heavy fibre (branches) we may simply not need them, so evolution would stop selecting for them * This says cities, but it (a) only appears to look at the US, and (b) the article doesn't mention comparing to non-city dwellers in the US. Saying "cities" without also providing a non-city reference seems bogus, but also could simply be left out of the article. * Following from the "US only" comment above - how stable is this microbiome between geographical regions in the US?, how about different countries in close geographic location (think Europe)?, or geographically separated countries with similar culture? different culture? All of these things might be answered in the paper, but per-usual Science has given us a fairly useless summary article with a clickbait headline :-( [Edited to bring back formatting. For a text only, anti-emoji, etc site HN is obnoxiously opposed to basic white space formatting :-/]
rr888 4y ago
Does anyone know of probiotics with a variety of bacteria? Currently they (and yoghurts) seem to be just a single type, which doesn't make a lot of sense to me. If there are unusual bacteria out there where do they come from and how can we get them? I've done a bunch of anti-biotics in the last few years so what to get back to what I was.
- giantg2 4y ago
  "Does anyone know of probiotics with a variety of bacteria?" Home fermenting and raw products (honey, fruit, veggies, etc) are probably a good place for variety. You may have a primary strain you're fermenting with, but there are likely other minority strains present too.
- trollied 4y ago
  I started taking these a month ago. They’ve worked wonders for my IBS: Healthspan Super20 Pro 60 https://www.amazon.co.uk/dp/B085632HRB https://www.amazon.co.uk/dp/B085632HRB
  - wnolens 4y ago
    What have you noticed? (I have IBS-C)
- Splendor 4y ago
  A quick search turned up this one that claims to have 12 strains of bacteria. It is also USP verified. I'm not an expert and have never tried it, but hopefully that info helps. https://www.costco.com/trunature-advanced-digestive-probiotic%2c-100-capsules.product.100387855.html https://www.costco.com/trunature-advanced-digestive-probioti...
- prirun 4y ago
  I've had good luck with these, taken one in the morning and one at night. https://www.amazon.com/Probiotics-Formulated-Probiotic-Supplement-Acidophilus/dp/B079H53D2B https://www.amazon.com/Probiotics-Formulated-Probiotic-Suppl... Now, instead of taking the probiotics, I make yogurt from whole milk (it's easy!) and open 3 probiotic capsules as the starter, letting it ferment for 24 hours to ensure all of the milk sugar is gone. This gives 2 quarts of yogurt and I eat a tablespoon every morning with breakfast. Way cheaper than the pills, plus I have a problem swallowing the capsules. Has worked great for me.
boomchinolo78 4y ago
It's the iron fortified flour and then the people are like OMG I have celiac and what not. There's a reason breast milk and milk in general contains lactoferrin; guess what, they also remove it from most milk that is in supermarkets.
- getcrunk 4y ago
  can you please expand on this?
- nebfield 4y ago
  The burden of proof for a coeliac disease diagnosis is quite high: a biopsy from an endoscopy that shows classic signs of damaged villi (from autoimmune mechanisms), or a blood test with extremely high tTG levels and a family history of the disease. https://www.bsg.org.uk/covid-19-advice/covid-19-specific-non-biopsy-protocol-guidance-for-those-with-suspected-coeliac-disease/ https://www.bsg.org.uk/covid-19-advice/covid-19-specific-non...
Splendor 4y ago
> ...a researcher reported last week at a microbiology meeting in Washington, D.C. Am I missing it or is this all we are given as a source for the claim in the headline? Not even a name?
wheelerof4te 4y ago
It's the diet. City dwellers tend to eat a lot more unhealthy foods. They also eat a lot less vegetables, fruit and nuts than their rural country(wo)men. You want more microbes in your gut? Eat more plant-based food.
- woodruffw 4y ago
  The study doesn't show this: it compares humans (who happen to live in cities) to primates (who definitely don't live in cities). It doesn't compare between human populations. Ironically, cities (particularly affluent ones, but in general) probably have better access to fresh and healthy produce than do medium or low-income rural areas. Some of that is supply and demand (the economics of moving bulk produce favor large population clusters), and some of it is pricing (affluent consumers prefer cities and suburbs on average). You can see these trends in the USDA's Food Atlas[1], which shows lots of rural areas with poor access to produce. [1]: https://www.ers.usda.gov/data-products/food-access-research-atlas/go-to-the-atlas/ https://www.ers.usda.gov/data-products/food-access-research-...
  - wheelerof4te 4y ago
- dagw 4y ago
  Having lived both in the city and fairly rural, I can say that access to a healthy and varied diet is much much easier in the city. Both when it came to restaurants and buying and cooking food.
  - quickthrower2 4y ago
    Small town / suburban areas can be the best with large supermarkets or dedicated markets, as long as you have a car. That said bushland in Australia has natives that you can’t buy in the supermarket. So there is that. But the average person probably doesn’t forage.
  - wtetzner 4y ago
asdff 4y ago
Pretty much every culture around the world 100 years ago had some staple fermented food. Nowadays, a lot of people in western culture at least outright refuse yogurt or other fermented foods like saurkraut or pickled cabbage that used to be staples in these people's ancestor's diets a few generations ago. People are becoming even lactose intolerant. You have to fertilize your microbes so to speak and eat these sorts of foods. Plus once you are doing stuff like making your own yogurt, a jug of whole milk works out a lot cheaper than the chobani stuff.
- amarshall 4y ago
  > You have to fertilize your microbes so to speak and eat these sorts of foods [citation needed]. It seems unlikely that fermented foods are not consumed in urban areas at all. I’ve also no idea if other primates consume any fermented foods, but I’d guess probably not. > People are becoming even lactose intolerant Do any other primates drink milk after infancy? If not, that’s not really a valid concern in the context of the article.
  - msbarnett 4y ago
    No. In fact, almost all mammals stop producing lactase once they stop nursing from a mother. Humans are quite rare in that there's a significant population with the mutant "lactose tolerant adult" gene.
  - bobthepanda 4y ago
    The study is of US cities. I would be curious to see if you took, say, South Korean cities, what the results would be. (Seoul is one of the largest megacities in the world, and kimchi is an extremely common fermented food.)
- steve_adams_86 4y ago
  One tricky part with fermented foods is that the salty ones appear to increase rates of colon and stomach cancer as I recall. I read something years ago about how as the Japanese population adapted a more western diet, heaps of ailments came upon them as you’d expect, but their salt intake declined so dramatically that they stopped experiencing stroke and GI tract cancers nearly as much. I think you’d need to pin down just how much salt was causing those issues though and then ask if the benefits of the salty fermented foods outweigh the current problem of having depleted gut microbiomes and atrocious diets. So, I’m certainly not suggesting everyone avoid salty fermented foods. I eat (and make) a fair amount myself and as I alluded above, I suspect it’s better for me than eating food that is, on balance, worse for me. There’s no perfect diet, but there are clearly worse diets. I try to avoid the latter.
jschveibinz 4y ago
Microbiome research at John’s Hopkins: https://www.hopkinsmicrobiome.com/faq https://www.hopkinsmicrobiome.com/faq
kaycebasques 4y ago
I had to use oral antibiotics about a year ago for reasons that could have been avoided. I was pretty upset about it precisely because it probably wreaked havoc on all the beneficial gut microbes that I had built up over the years.
- HeyLaughingBoy 4y ago
  I had a couple courses of IV antibiotics to fight a severe tooth infection. All the oral surgeons who came in to check on me recommended picking up a few bottles of probiotic drinks on my way home.
  - hinkley 4y ago
    And some cheddar cheese. https://en.wikipedia.org/wiki/Lacticaseibacillus_casei https://en.wikipedia.org/wiki/Lacticaseibacillus_casei is theorized to be a sort of a halo probiotic - it doesn't do the work, but it makes you GI tract more hospitable to the bacteria that do. There are cheddar cheeses though that barely rank the name. Quality over quantity here. Buy the small block of fancy cheddar, not whatever name the food megacorporations are using locally.
- Spinosaurus 4y ago
  Have you had any lasting effects? I've been prescribed a "fairly serious" antibiotic for a skin condition that has been plaguing me for several years (I've gotten like 5 different diagnosis and tons of different Rx). I'm otherwise incredibly healthy, so this antibiotic scares the shit out of me and I have yet to start taking it.
  - kaycebasques 4y ago
    No lasting effects but it was only a year ago so who knows - my completely amateur take is you've got to balance the payoff with the risk - in your case the payoff of getting rid of a skin condition that's been plaguing me for years seems like a fair trade for the risk of the antibiotics if I were in your shoes... it's not like you didn't try to let your body resolve it on its own (since you've had it for years)
afarviral 4y ago
I'd be really curious where some of these wild microbes can be found so we can repopulate them. Every time I brush my teeth, use dish washing liquid or really any man made substance with a lots of ingredients I also wonder if I'm accidentally killing off my skin/mouth/gut microbiomes. Not worried enough to only use water (not that tap water can be fully trusted either....)
- Bilal_io 4y ago
  Explore the use of Miswak for your teeth.
digitcatphd 4y ago
I think the consensus is nobody really knows and nutritional science is largely trendy pseudoscience…
- starwind 4y ago
  I've always been shocked at how crappy the research into nutrition is and how there's very little consensus beyond "vegetables are good" and how shoddy a lot of the professional training is for dieticians. Nearly everybody eats nearly every day, how have we not figured this out?
  - onkoe 4y ago
    Everyone wants to be the one eating - no one wants to be the foodless researcher.
    - dennis_jeeves1 4y ago
      Also mortgages to pay, and mouths of feed of this little brats they pop out are all valid reasons....
  - astrange 4y ago
    It's both difficult and largely unethical to do intervention studies on people, and we don't know how to measure individual differences between people very well. For instance, studying gut biomes of people is mainly done by looking at their poop but that doesn't help you know what kind of bacteria are where in their intestines, and it's not like you can take them apart.
  - somenameforme 4y ago
    I think there's a pretty simple explanation for this. How many calories should you consume per day? It's a trick question because it has no answer. It's going to vary dramatically depending upon environmental, physical/physiological, and genetic characteristics. And that is probably the most simple question to answer, because when you get into the specifics of nutritional content, the same is true except it's orders of magnitudes more complex with far less understood. And many things come down to pretty precise measurement because it's all systems in equilibrium. 100 calories to your diet would ostensibly have a negligible impact because it's not much relative to your entire intake, but if you were just at the equilibrium where your consume - burn = 0, then that 100 calories is suddenly going to start seeing you gain weight dramatically faster than before.
baby 4y ago
How does probiotic helps here?
subsubzero 4y ago
Lacking these gut microbes has been posited to lead to depression and effect mood by a few researchers: https://www.science.org/content/article/evidence-mounts-gut-bacteria-can-influence-mood-prevent-depression https://www.science.org/content/article/evidence-mounts-gut-...
- TranquilMarmot 4y ago
  The future of antidepressants is fecal transplants for healthy gut bacteria (not even kidding)
  - badkitty99 4y ago
- baronswindle 4y ago
  > The researchers can't say whether the absence is a cause or an effect of the illness My immediate thought was that people suffering from depression might eat more “junk food” due to the depression and that their poor diets might lay waste to their gut biomes. Of course, there may be other studies that contradict my hypothesis.
LightG 4y ago
Interesting. Perhaps someone could do a geographical survey of people with IBD (Colitis / Chrons / etc).
tompccs 4y ago
I'd put microbiome research high up on my list of things which will turn out to be junk science in a few years. A lot of the actual numbers in this are pretty tenuous. Primates have 80 species of bacteria and city dwellers have 50? Wow, stop the presses. A few years ago the fashionable thing was colonic irrigation (see https://journals.lww.com/ajg/fulltext/2009/11000/clinical_effects_of_colonic_cleansing_for_general.32.aspx https://journals.lww.com/ajg/fulltext/2009/11000/clinical_ef...). Now it just seems the pendulum has swung the other way and we need more crap in our colons, not less. We're looking for reasons why we feel sick all the time but the reality is beyond basic things like being too fat and too sedentary, we are healthier than ever, and many many people had wretched miserable lives of chronic pain before modernity. The expectation of health is a modern conceit and this research is just a reflection of the constant anxiety that there is something wrong with us all - a cultural hypochondria.
- actually_a_dog 4y ago
  Given that the ratio of bacterial to human cells in a typical human is about 1:1, I'd wager you're wrong on that. This sounds rather like a "shallow dismissal" that buts up against the gudelines here, as well. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4991899/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4991899/ https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
- dhzhzjsbevs 4y ago
  I'll take that bet. I think we're going to find the opposite in a few years.
- corrral 4y ago
  > We're looking for reasons why we feel sick all the time but the reality is beyond basic things like being too fat and too sedentary, we are healthier than ever, and many many people had wretched miserable lives of chronic pain before modernity. The expectation of health is a modern conceit and this research is just a reflection of the constant anxiety that there is something wrong with us all - a cultural hypochondria. Truly, "eat less trash; eat more veggies; eat less total; and move around at least an hour a day" is such good advice for most of us in "the West" that following it somewhat well would provide 100x more benefit than the next-closest thing. Plastic additives? Gut microbes? Fructose versus sucrose? Balance of omega fatty acids? Specific exercise routines? Forget all that unless you're already eating really well and staying active daily, which very few of us are. When I read articles about these kinds of things and start to get the urge to act on them, I try to remind myself that I should go do a few squats or walk around the block a couple times instead.
david_l_lin 4y ago
I wonder if the same is happening to mouth microbes, which could explain the epidemic of oral disease in developed countries.
swayvil 4y ago
Therefore the city dweller must be somewhat insane. Because the gut biome is a key component in our central nervous system. It's basically the seat of emotion. Anybody notice any funny behavior out of the cities lately?
mulmen 4y ago
This article is mostly cliche popsci trash that isn’t worth reading. Good for a game of logical fallacy bingo. The only interesting development seems to be the methodology but that only gets a passing mention. The rest is basically fearmongering. > In humans, for example, gut bacteria influence how the immune system responds to pathogens and allergens, or interact with the brain, affecting mood. Ok. But what does that have to do with diversity? Humans have not been an emotionally rational species at any point in the past. Arguably the relationship between gut biome diversity and civilization is inverse. Maybe we want fewer microbes. Lifespan has also increased with decreased gut biome diversity. This is why correlation alone is uninteresting. You can find it anywhere. > Splitting the difference, people in less developed parts of the world have between 60 and 65 of those bacterial groups, an observation that ties the decrease in microbial diversity to urbanization. Oh come on. How does a line like this get published? This is fine if you define “ties” as “moves with” but not “is connected to”. IOW correlation doesn’t imply causation. > Kyle Meyer, a microbiologist at UC Berkeley, argues such losses are not necessarily a problem. “Maybe we don’t need them,” he points out. But Moeller is worried. “We are really doing some scary stuff to our microbiomes,” he warns. Why is it “scary”? Nothing in this article established any cause for concern. The guy that developed the methodology is now in search of a problem his solution fits.
- pojzon 4y ago
  Whats scary is that we have more and more civilization diseases and we have no idea whats causing them beside guesses. Worsening of the environment we live in impacts us in ways we cannot even imagine. Scary is that we cannot go back, coz its financially impossible for most.
  - majormajor 4y ago
    Cities were historically unhealthy, etc, etc, as well. Yet people kept moving to them. So "most people can't afford to [leave civiliation]" is far from new. Perhaps the life everyone has been fleeing to get to cities was never what you think it is for most.
    - 4y ago
mjsweet 4y ago
Can someone comment on the effect of chlorinated town water on gut microbes? Would treated water have an affect as opposed to consuming rain or bore water?
- altfredd 4y ago
  > effect of chlorinated town water on gut microbes Unless you are drinking a tap water (pretty extreme thing to do!), the effect is probably non-existing: https://cooking.stackexchange.com/q/67027 https://cooking.stackexchange.com/q/67027
  - mdp2021 4y ago
    > Unless you are drinking a tap water (pretty extreme thing to do!) Around your parts you do not drink tap water?
    - rmetzler 4y ago
      My understanding is that the amount of chlorine added to the tap water differs between regions. I read it can be a lot in the US. Here in Germany there is a limit by law of 0.3mg per liter and most districts use between 0.03mg and 0.05mg per liter. We drink tap water daily. There is no noticeable chlorine smell but I heard from friends their cat seems to not like it and drinks rainwater only.
  - mjsweet 4y ago
    I live in Australia, I would say most people would drink tap water at home. We have a sink top filter that filters water, so we use that. I don’t think drinking tap water in this part of the world is abnormal, on the contrary. Out of curiosity, where are you from?
insaider 4y ago
A theory: this decrease in gut microbiome diversity directly correlates with an increase in fatigue. Ever since the first time I had antibiotics I've suffered from chronic fatigue, I'm pretty sure there's a strong connection here to the bacteria in my gut as it often feels like the main symptom is a reduced ability to digest food.
ppeetteerr 4y ago
Only the bad ones, I hope
ryanisnan 4y ago
That's why I live in the country and gorge myself on literal feces.
ck2 4y ago
year ago in WSJ https://archive.today/rCjpO https://archive.today/rCjpO
bayesian_horse 4y ago
I've heard fecal transplants are the latest shit in healthcare...
somenameforme 4y ago
I'm curious how simple sanitary factors come into play. Something I've always found intriguing is that in Ancient Greece toilets would use shared butt brushes (sponge on a stick) in lieu of toilet paper. In an especially fancy place there might be a bucket of vinegar nearby to clean it off, but in general it was just a quick swirl through some water and onto the next bum. The thing I find interesting there is that the Ancient Greeks had extremely limited medical knowledge alongside practices like this. And they also lived through less than pleasant times, yet they were often also quite long lived as a quick perusal of your Philosophacrates of choice can readily demonstrate. There's certainly a literal survivorship bias there, but the ubiquitousness of longevity is, if nothing else, interesting. Certainly many of these individuals would have still left their mark had they died at 40 or 50 instead.
- moreira 4y ago
  It seems like it’s about statistics, more than anything. Some people can be sedentary and smoke their whole lives and eat lard non stop and still live to be 80. Doesn’t mean any of that helped them in any way. It’s like that for them, too; regardless of their sanitary practices, some people will live to be old. On its own I don’t think it says much about their effectiveness. Long-lived people have always existed. The difference is in the % of people that make it that far.
  - somenameforme 4y ago
    That's exactly what I was hitting on. Ancient Greeks living to quite old age were not statistical outliers, but the norm! The only way to explain this with contemporary understanding is to suggest it's just an extremely large survivorship bias, but that seems to difficult to swallow because many of those we know of from Ancient Greece we would likely still know of even had they died decades earlier as well. This [1] study looked at the mean age of Greeks "of renown" from the 5th and 4th century and found the average life expectancy was 71.3 years! There's certainly a class bias, but when we're speaking of times of antiquity all the money it world couldn't buy you what didn't exist. So all that bias would represent is, at best, more or less secure access to food, drink, and other basic necessities. [1] - https://pubmed.ncbi.nlm.nih.gov/18359748/ https://pubmed.ncbi.nlm.nih.gov/18359748/
deleted 4y ago
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infologics 4y ago
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rawoke083600 4y ago
I'm waiting for the "designer fecal supplements". i.e fecal transplants.
kewrkewm53 4y ago
I wonder how much of the fast increasing prevalence of gut-related diseases like IBS can be explained by the changes in gut microbes, and how much is just about lack of exercise and changes in diet. Whenever I go work at relative's farm my stomach seems to work way better, even though I do plenty of exercise in my home city as well. Perhaps the type of manual labor is better for stomach than gym/running, but I wouldn't rule out the impact of microbes either.
benknight87 4y ago
I really enjoyed reading Fiber Fueled which basically lays out how all the latest science links our overall health very closely to the health and diversity of our microbiome. It will be interesting to see if new research continues to find evidence to support this. It's also a pretty convincing scientific argument in support for plant-based diets which, conveniently, is good for the planet and animal welfare as well.
qwerty456127 4y ago
> “perhaps we can restore them with probiotics.” Really? AFAIK probiotics, as well as antibiotics, can only affect the gut microbiome temporarily - it will restore to the baseline (defined in early childhood) if left alone and given some time. Isn't it so?
- dragonwriter 4y ago
  > AFAIK probiotics, as well as antibiotics, can only affect the gut microbiome temporarily - it will restore to the baseline (defined in early childhood) if left alone and given some time. Isn't it so? Seems to be more complicated, and differ for different types of bacteria in the gut microbiome. https://www.embl.org/news/science/gut-microbiome-changes-over-time/ https://www.embl.org/news/science/gut-microbiome-changes-ove...
tomcam 4y ago
I found them in the seat of an Uber during spring break
db1234 4y ago
Could this explain trends like increasing food allergies in countries where more and more people are becoming urban dwellers?
- epgui 4y ago
  It's not impossible, and it might even be plausible... But it's a really, really difficult question. People outside of science: don't make the mistake of thinking that scientists haven't thought about this before! haha
  - bejelentkezni 4y ago
    What is that supposed to mean?
    - monocasa 4y ago
      That it's certainly a valid thought with the information we have, and is being thought about, but requires further investigation to make an affirmative statement.
      - deleted 4y ago
        [deleted]
      - epgui 4y ago
        ^ This is the best explanation of what I meant.
    - timfsu 4y ago
      Guessing that this means there are a lot of confounding variables other than gut biome (environment, diet, genetics, etc) that are very difficult to isolate to prove causation, as opposed to correlation.
      - K0SM0S 4y ago
        Gut biome being one of the most promising area of research, whose earth-shattering potential is about on par with the sheer complexity of the problem. If you thought ML was difficult, try modeling a human being's digestive tube from mouth to anus down to the cell: welcome to a category of problems where climate and gravity are the "simple" ones. On the other side of that space though, potentially the promise to increase by orders of magnitude our mastery of human condition both biologically and experientially.
lbeltrame 4y ago
About ten years ago my former PI (second author in the below paper) did quite a job on this in Burkina Faso, analyzing the composition of the gut in children living outside cities, in cities, and a comparison with European children. Obligatory disclaimer: I was working in his laboratory at the time, but I wasn't involved in that research. https://www.pnas.org/doi/10.1073/pnas.1005963107 https://www.pnas.org/doi/10.1073/pnas.1005963107
- jonny_eh 4y ago
  What's a "former PI"?
  - sieabahlpark 4y ago
  - chronometry888 4y ago
    The private investigator with whom you have severed ties.
  - vanattab 4y ago
    principal investigator
  - trollied 4y ago
    “The person(s) in charge of a clinical trial or a scientific research grant. The PI prepares and carries out the clinical trial protocol (plan for the study) or research paid for by the grant. The PI also analyzes the data and reports the results of the trial or grant research. Also called principal investigator.”
  - deleted 4y ago
    [deleted]
  - alienchow 4y ago
  - etiam 4y ago
goatcode 4y ago
>people in U.S. cities...people in less developed parts of the world What about people in the US who are not in cities? That's the more interesting comparison to me. Why would that be left out?
- jascii 4y ago
  I'm curious why that comparison is more interesting to you? I can see great value in having both data points when trying to formulate a hypothesis about what causes the decline in gut-microbes in us city folks, but I find it hard to think of a use-case for solely a urban/rural comparison without other context. (Update: I was thinking about this from a scientific perspective, ignoring the idea that people might be interested in what it means for them personally (facepalm) )
  - runjake 4y ago
    Because a bunch of us don't live in the city or urban environments and we're curious.
    - jascii 4y ago
      So the interest stems from a curiosity about your own gut-microbes? That seems fair enough, I may have been overthinking this...
  - goatcode 4y ago
    I shouldn't say more overall, but the difference among people who have a similar diet and circumstances, but differ by housing culture, would be interesting to observe. I'd like to see apples to apples, if indeed the theorized reason of where gut differences come from is strictly (or mostly) urban vs. rural. Is it that country people are around more dirt, or that city people have different stressors, or maybe both are included? It'd be easier to tell if other differences are eliminated, imo. I've long preferred country life, having spent roughly half of my life in cities and the other half in the country, so maybe some personal interest is there too, to be honest. I do feel a lot healthier living in the countryside, perhaps my gut has something to do with that.
samstave 4y ago
- epgui 4y ago
  I'm unable to verify that quote. Also, it's irrelevant, and not really true at all.
  - samstave 4y ago
    - epgui 4y ago
      You're right, I don't see the humour in this. And it's not pedantic to question a misquoting when the meaning is completely different. Nor is it pedantic to question the relevance of someone's comment. I don't think this quote means what you think it means.
      - samstave 4y ago
        >>that being mindful about the language we choose to accept socially is in general radical Yeah, you're a hypocrite. I am not upset, but based on your comment history, I actually expect higher of you. "question a misquoting" <-- You didnt even get the FN quote in the first place, then attempt to make yourself all "enlightened" Give me a FN break... Your feigned self-righteous demeanor simply devalues your Truth, and I am assured that you will defend your mental superiority, regardless.. My Grandmother, would oft state: "often in err, never in doubt"
        epgui 4y ago
        Please see the rules for commenting on Hacker News: https://news.ycombinator.com/newsguidelines.html#comments https://news.ycombinator.com/newsguidelines.html#comments
dukeofdoom 4y ago
haklport 4y ago
"Moeller and others also suggest identifying the missing microbes may be the first step toward bringing them back. “If we determine that these groups were providing important functions to keep humans healthy,” Maccaro says, “perhaps we can restore them with probiotics.” Oh really? Nice submarine for Actimel, Yakult etc.
- antiterra 4y ago
  Unfortunately, the most effective treatment I know of to change gut biome is bacteriotherapy via a method many people find off-putting and violating. I think, for the time being, people are much more likely to accept a probiotic.
  - thematrixturtle 4y ago
    I take it you mean fecal transplants, aka inserting somebody else's feces up your rectum?
    - insamniac 4y ago
      transpoosion
- zdragnar 4y ago
  Well, it's either a pill, or moving out of the city, or a fecal transplant (assuming that the urban / rural divide is relevant, and not just a proxy for diet). I don't live in the city, but if I were told that I would be healthier with more of these microbes that my environment doesn't support, I'd opt for the pill.
  - jgrantx 4y ago
    Doing nothing is also an option! I'm not aware of an indigestion epidemic among city dwellers. Being told to do something is not sufficient, especially when multi-billion dollar industries are behind it.

398 points by Hooke 4y ago

bmj 4y ago

Requisite xkcd: https://xkcd.com/1471/ https://xkcd.com/1471/

Once a gene has started expressing, it's pretty hard to flip the switch back to the off position. Losing the microbes is a big problem. It's just going to get worse. People seem to have this fetish for anti-bacterial everything.. soaps, coatings, etc. They take anti-biotics even for viral issues then they wonder why they start developing a new health problem they didn't have before, like a mood disorder or an autoimmune issue.

olliej 4y ago
What did the lost microbes do? If they helped digest things that aren't part of our diet then the there would be no selective pressure maintaining them, so they could be easily dropped, independent of the issues of vast over-application of antibiotics, etc. Over application of antibiotics and anti-bacterial stuff is clearly causing problems, but that's not the only thing that is happening that impacts something as complex as the gut. Just as with genes, the microbiome is under constant selective pressure from evolution, and we will - over time - gain new microbes as we lose ones that aren't beneficial.
thelittleone 4y ago
Here in Indonesia, antibiotics can be bought over the counter without a prescription. Many people self medicate for a cough or runny nose (they don't distinguish whether viral or bacterial, most likely the average worker doesn't know the difference). Few have the luxury to take a sick day so the pressure is on.
- Sunspark 4y ago
  This should be an election issue, that Indonesia should not be selling antibiotics without a prescription. Stupid people take them just a little then stop, and as a result are continually training tuberclosis and other bacteria to become antibiotic resistant. Then when they can't treat things anymore, surprised Indonesian faces all around. What if the West doesn't have anything new for them? Time to die. Before antibiotics, was not a fun time and we're heading back there soon.

olliej 4y ago

My first thoughts are (without access to the actual article) * We have lost the microbiome that primates present * have we gained other microbes? * what did those microbes we lost do? If they break down heavy fibre (branches) we may simply not need them, so evolution would stop selecting for them * This says cities, but it (a) only appears to look at the US, and (b) the article doesn't mention comparing to non-city dwellers in the US. Saying "cities" without also providing a non-city reference seems bogus, but also could simply be left out of the article. * Following from the "US only" comment above - how stable is this microbiome between geographical regions in the US?, how about different countries in close geographic location (think Europe)?, or geographically separated countries with similar culture? different culture? All of these things might be answered in the paper, but per-usual Science has given us a fairly useless summary article with a clickbait headline :-( [Edited to bring back formatting. For a text only, anti-emoji, etc site HN is obnoxiously opposed to basic white space formatting :-/]

rr888 4y ago

Does anyone know of probiotics with a variety of bacteria? Currently they (and yoghurts) seem to be just a single type, which doesn't make a lot of sense to me. If there are unusual bacteria out there where do they come from and how can we get them? I've done a bunch of anti-biotics in the last few years so what to get back to what I was.

giantg2 4y ago
"Does anyone know of probiotics with a variety of bacteria?" Home fermenting and raw products (honey, fruit, veggies, etc) are probably a good place for variety. You may have a primary strain you're fermenting with, but there are likely other minority strains present too.
trollied 4y ago
I started taking these a month ago. They’ve worked wonders for my IBS: Healthspan Super20 Pro 60 https://www.amazon.co.uk/dp/B085632HRB https://www.amazon.co.uk/dp/B085632HRB
- wnolens 4y ago
  What have you noticed? (I have IBS-C)
Splendor 4y ago
A quick search turned up this one that claims to have 12 strains of bacteria. It is also USP verified. I'm not an expert and have never tried it, but hopefully that info helps. https://www.costco.com/trunature-advanced-digestive-probiotic%2c-100-capsules.product.100387855.html https://www.costco.com/trunature-advanced-digestive-probioti...
prirun 4y ago
I've had good luck with these, taken one in the morning and one at night. https://www.amazon.com/Probiotics-Formulated-Probiotic-Supplement-Acidophilus/dp/B079H53D2B https://www.amazon.com/Probiotics-Formulated-Probiotic-Suppl... Now, instead of taking the probiotics, I make yogurt from whole milk (it's easy!) and open 3 probiotic capsules as the starter, letting it ferment for 24 hours to ensure all of the milk sugar is gone. This gives 2 quarts of yogurt and I eat a tablespoon every morning with breakfast. Way cheaper than the pills, plus I have a problem swallowing the capsules. Has worked great for me.

boomchinolo78 4y ago

It's the iron fortified flour and then the people are like OMG I have celiac and what not. There's a reason breast milk and milk in general contains lactoferrin; guess what, they also remove it from most milk that is in supermarkets.

getcrunk 4y ago
can you please expand on this?
nebfield 4y ago
The burden of proof for a coeliac disease diagnosis is quite high: a biopsy from an endoscopy that shows classic signs of damaged villi (from autoimmune mechanisms), or a blood test with extremely high tTG levels and a family history of the disease. https://www.bsg.org.uk/covid-19-advice/covid-19-specific-non-biopsy-protocol-guidance-for-those-with-suspected-coeliac-disease/ https://www.bsg.org.uk/covid-19-advice/covid-19-specific-non...

Splendor 4y ago

> ...a researcher reported last week at a microbiology meeting in Washington, D.C. Am I missing it or is this all we are given as a source for the claim in the headline? Not even a name?

wheelerof4te 4y ago

It's the diet. City dwellers tend to eat a lot more unhealthy foods. They also eat a lot less vegetables, fruit and nuts than their rural country(wo)men. You want more microbes in your gut? Eat more plant-based food.

woodruffw 4y ago
The study doesn't show this: it compares humans (who happen to live in cities) to primates (who definitely don't live in cities). It doesn't compare between human populations. Ironically, cities (particularly affluent ones, but in general) probably have better access to fresh and healthy produce than do medium or low-income rural areas. Some of that is supply and demand (the economics of moving bulk produce favor large population clusters), and some of it is pricing (affluent consumers prefer cities and suburbs on average). You can see these trends in the USDA's Food Atlas[1], which shows lots of rural areas with poor access to produce. [1]: https://www.ers.usda.gov/data-products/food-access-research-atlas/go-to-the-atlas/ https://www.ers.usda.gov/data-products/food-access-research-...
- wheelerof4te 4y ago
dagw 4y ago
Having lived both in the city and fairly rural, I can say that access to a healthy and varied diet is much much easier in the city. Both when it came to restaurants and buying and cooking food.
- quickthrower2 4y ago
  Small town / suburban areas can be the best with large supermarkets or dedicated markets, as long as you have a car. That said bushland in Australia has natives that you can’t buy in the supermarket. So there is that. But the average person probably doesn’t forage.
- wtetzner 4y ago

asdff 4y ago

Pretty much every culture around the world 100 years ago had some staple fermented food. Nowadays, a lot of people in western culture at least outright refuse yogurt or other fermented foods like saurkraut or pickled cabbage that used to be staples in these people's ancestor's diets a few generations ago. People are becoming even lactose intolerant. You have to fertilize your microbes so to speak and eat these sorts of foods. Plus once you are doing stuff like making your own yogurt, a jug of whole milk works out a lot cheaper than the chobani stuff.

amarshall 4y ago
> You have to fertilize your microbes so to speak and eat these sorts of foods [citation needed]. It seems unlikely that fermented foods are not consumed in urban areas at all. I’ve also no idea if other primates consume any fermented foods, but I’d guess probably not. > People are becoming even lactose intolerant Do any other primates drink milk after infancy? If not, that’s not really a valid concern in the context of the article.
- msbarnett 4y ago
  No. In fact, almost all mammals stop producing lactase once they stop nursing from a mother. Humans are quite rare in that there's a significant population with the mutant "lactose tolerant adult" gene.
- bobthepanda 4y ago
  The study is of US cities. I would be curious to see if you took, say, South Korean cities, what the results would be. (Seoul is one of the largest megacities in the world, and kimchi is an extremely common fermented food.)
steve_adams_86 4y ago
One tricky part with fermented foods is that the salty ones appear to increase rates of colon and stomach cancer as I recall. I read something years ago about how as the Japanese population adapted a more western diet, heaps of ailments came upon them as you’d expect, but their salt intake declined so dramatically that they stopped experiencing stroke and GI tract cancers nearly as much. I think you’d need to pin down just how much salt was causing those issues though and then ask if the benefits of the salty fermented foods outweigh the current problem of having depleted gut microbiomes and atrocious diets. So, I’m certainly not suggesting everyone avoid salty fermented foods. I eat (and make) a fair amount myself and as I alluded above, I suspect it’s better for me than eating food that is, on balance, worse for me. There’s no perfect diet, but there are clearly worse diets. I try to avoid the latter.

jschveibinz 4y ago

Microbiome research at John’s Hopkins: https://www.hopkinsmicrobiome.com/faq https://www.hopkinsmicrobiome.com/faq

kaycebasques 4y ago

I had to use oral antibiotics about a year ago for reasons that could have been avoided. I was pretty upset about it precisely because it probably wreaked havoc on all the beneficial gut microbes that I had built up over the years.

HeyLaughingBoy 4y ago
I had a couple courses of IV antibiotics to fight a severe tooth infection. All the oral surgeons who came in to check on me recommended picking up a few bottles of probiotic drinks on my way home.
- hinkley 4y ago
  And some cheddar cheese. https://en.wikipedia.org/wiki/Lacticaseibacillus_casei https://en.wikipedia.org/wiki/Lacticaseibacillus_casei is theorized to be a sort of a halo probiotic - it doesn't do the work, but it makes you GI tract more hospitable to the bacteria that do. There are cheddar cheeses though that barely rank the name. Quality over quantity here. Buy the small block of fancy cheddar, not whatever name the food megacorporations are using locally.
Spinosaurus 4y ago
Have you had any lasting effects? I've been prescribed a "fairly serious" antibiotic for a skin condition that has been plaguing me for several years (I've gotten like 5 different diagnosis and tons of different Rx). I'm otherwise incredibly healthy, so this antibiotic scares the shit out of me and I have yet to start taking it.
- kaycebasques 4y ago
  No lasting effects but it was only a year ago so who knows - my completely amateur take is you've got to balance the payoff with the risk - in your case the payoff of getting rid of a skin condition that's been plaguing me for years seems like a fair trade for the risk of the antibiotics if I were in your shoes... it's not like you didn't try to let your body resolve it on its own (since you've had it for years)

afarviral 4y ago

I'd be really curious where some of these wild microbes can be found so we can repopulate them. Every time I brush my teeth, use dish washing liquid or really any man made substance with a lots of ingredients I also wonder if I'm accidentally killing off my skin/mouth/gut microbiomes. Not worried enough to only use water (not that tap water can be fully trusted either....)

Bilal_io 4y ago
Explore the use of Miswak for your teeth.

digitcatphd 4y ago

I think the consensus is nobody really knows and nutritional science is largely trendy pseudoscience…

starwind 4y ago
I've always been shocked at how crappy the research into nutrition is and how there's very little consensus beyond "vegetables are good" and how shoddy a lot of the professional training is for dieticians. Nearly everybody eats nearly every day, how have we not figured this out?
- onkoe 4y ago
  Everyone wants to be the one eating - no one wants to be the foodless researcher.
  - dennis_jeeves1 4y ago
    Also mortgages to pay, and mouths of feed of this little brats they pop out are all valid reasons....
- astrange 4y ago
  It's both difficult and largely unethical to do intervention studies on people, and we don't know how to measure individual differences between people very well. For instance, studying gut biomes of people is mainly done by looking at their poop but that doesn't help you know what kind of bacteria are where in their intestines, and it's not like you can take them apart.
- somenameforme 4y ago
  I think there's a pretty simple explanation for this. How many calories should you consume per day? It's a trick question because it has no answer. It's going to vary dramatically depending upon environmental, physical/physiological, and genetic characteristics. And that is probably the most simple question to answer, because when you get into the specifics of nutritional content, the same is true except it's orders of magnitudes more complex with far less understood. And many things come down to pretty precise measurement because it's all systems in equilibrium. 100 calories to your diet would ostensibly have a negligible impact because it's not much relative to your entire intake, but if you were just at the equilibrium where your consume - burn = 0, then that 100 calories is suddenly going to start seeing you gain weight dramatically faster than before.

baby 4y ago

How does probiotic helps here?

subsubzero 4y ago

Lacking these gut microbes has been posited to lead to depression and effect mood by a few researchers: https://www.science.org/content/article/evidence-mounts-gut-bacteria-can-influence-mood-prevent-depression https://www.science.org/content/article/evidence-mounts-gut-...

TranquilMarmot 4y ago
The future of antidepressants is fecal transplants for healthy gut bacteria (not even kidding)
- badkitty99 4y ago
baronswindle 4y ago
> The researchers can't say whether the absence is a cause or an effect of the illness My immediate thought was that people suffering from depression might eat more “junk food” due to the depression and that their poor diets might lay waste to their gut biomes. Of course, there may be other studies that contradict my hypothesis.

LightG 4y ago

Interesting. Perhaps someone could do a geographical survey of people with IBD (Colitis / Chrons / etc).

tompccs 4y ago

I'd put microbiome research high up on my list of things which will turn out to be junk science in a few years. A lot of the actual numbers in this are pretty tenuous. Primates have 80 species of bacteria and city dwellers have 50? Wow, stop the presses. A few years ago the fashionable thing was colonic irrigation (see https://journals.lww.com/ajg/fulltext/2009/11000/clinical_effects_of_colonic_cleansing_for_general.32.aspx https://journals.lww.com/ajg/fulltext/2009/11000/clinical_ef...). Now it just seems the pendulum has swung the other way and we need more crap in our colons, not less. We're looking for reasons why we feel sick all the time but the reality is beyond basic things like being too fat and too sedentary, we are healthier than ever, and many many people had wretched miserable lives of chronic pain before modernity. The expectation of health is a modern conceit and this research is just a reflection of the constant anxiety that there is something wrong with us all - a cultural hypochondria.

actually_a_dog 4y ago
Given that the ratio of bacterial to human cells in a typical human is about 1:1, I'd wager you're wrong on that. This sounds rather like a "shallow dismissal" that buts up against the gudelines here, as well. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4991899/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4991899/ https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
dhzhzjsbevs 4y ago
I'll take that bet. I think we're going to find the opposite in a few years.
corrral 4y ago
> We're looking for reasons why we feel sick all the time but the reality is beyond basic things like being too fat and too sedentary, we are healthier than ever, and many many people had wretched miserable lives of chronic pain before modernity. The expectation of health is a modern conceit and this research is just a reflection of the constant anxiety that there is something wrong with us all - a cultural hypochondria. Truly, "eat less trash; eat more veggies; eat less total; and move around at least an hour a day" is such good advice for most of us in "the West" that following it somewhat well would provide 100x more benefit than the next-closest thing. Plastic additives? Gut microbes? Fructose versus sucrose? Balance of omega fatty acids? Specific exercise routines? Forget all that unless you're already eating really well and staying active daily, which very few of us are. When I read articles about these kinds of things and start to get the urge to act on them, I try to remind myself that I should go do a few squats or walk around the block a couple times instead.

david_l_lin 4y ago

I wonder if the same is happening to mouth microbes, which could explain the epidemic of oral disease in developed countries.

swayvil 4y ago

Therefore the city dweller must be somewhat insane. Because the gut biome is a key component in our central nervous system. It's basically the seat of emotion. Anybody notice any funny behavior out of the cities lately?

mulmen 4y ago

This article is mostly cliche popsci trash that isn’t worth reading. Good for a game of logical fallacy bingo. The only interesting development seems to be the methodology but that only gets a passing mention. The rest is basically fearmongering. > In humans, for example, gut bacteria influence how the immune system responds to pathogens and allergens, or interact with the brain, affecting mood. Ok. But what does that have to do with diversity? Humans have not been an emotionally rational species at any point in the past. Arguably the relationship between gut biome diversity and civilization is inverse. Maybe we want fewer microbes. Lifespan has also increased with decreased gut biome diversity. This is why correlation alone is uninteresting. You can find it anywhere. > Splitting the difference, people in less developed parts of the world have between 60 and 65 of those bacterial groups, an observation that ties the decrease in microbial diversity to urbanization. Oh come on. How does a line like this get published? This is fine if you define “ties” as “moves with” but not “is connected to”. IOW correlation doesn’t imply causation. > Kyle Meyer, a microbiologist at UC Berkeley, argues such losses are not necessarily a problem. “Maybe we don’t need them,” he points out. But Moeller is worried. “We are really doing some scary stuff to our microbiomes,” he warns. Why is it “scary”? Nothing in this article established any cause for concern. The guy that developed the methodology is now in search of a problem his solution fits.

pojzon 4y ago
Whats scary is that we have more and more civilization diseases and we have no idea whats causing them beside guesses. Worsening of the environment we live in impacts us in ways we cannot even imagine. Scary is that we cannot go back, coz its financially impossible for most.
- majormajor 4y ago
  Cities were historically unhealthy, etc, etc, as well. Yet people kept moving to them. So "most people can't afford to [leave civiliation]" is far from new. Perhaps the life everyone has been fleeing to get to cities was never what you think it is for most.
  - 4y ago

mjsweet 4y ago

Can someone comment on the effect of chlorinated town water on gut microbes? Would treated water have an affect as opposed to consuming rain or bore water?

altfredd 4y ago
> effect of chlorinated town water on gut microbes Unless you are drinking a tap water (pretty extreme thing to do!), the effect is probably non-existing: https://cooking.stackexchange.com/q/67027 https://cooking.stackexchange.com/q/67027
- mdp2021 4y ago
  > Unless you are drinking a tap water (pretty extreme thing to do!) Around your parts you do not drink tap water?
  - rmetzler 4y ago
    My understanding is that the amount of chlorine added to the tap water differs between regions. I read it can be a lot in the US. Here in Germany there is a limit by law of 0.3mg per liter and most districts use between 0.03mg and 0.05mg per liter. We drink tap water daily. There is no noticeable chlorine smell but I heard from friends their cat seems to not like it and drinks rainwater only.
- mjsweet 4y ago
  I live in Australia, I would say most people would drink tap water at home. We have a sink top filter that filters water, so we use that. I don’t think drinking tap water in this part of the world is abnormal, on the contrary. Out of curiosity, where are you from?

insaider 4y ago

A theory: this decrease in gut microbiome diversity directly correlates with an increase in fatigue. Ever since the first time I had antibiotics I've suffered from chronic fatigue, I'm pretty sure there's a strong connection here to the bacteria in my gut as it often feels like the main symptom is a reduced ability to digest food.

ppeetteerr 4y ago

Only the bad ones, I hope

ryanisnan 4y ago

That's why I live in the country and gorge myself on literal feces.

ck2 4y ago

year ago in WSJ https://archive.today/rCjpO https://archive.today/rCjpO

bayesian_horse 4y ago

I've heard fecal transplants are the latest shit in healthcare...

somenameforme 4y ago

I'm curious how simple sanitary factors come into play. Something I've always found intriguing is that in Ancient Greece toilets would use shared butt brushes (sponge on a stick) in lieu of toilet paper. In an especially fancy place there might be a bucket of vinegar nearby to clean it off, but in general it was just a quick swirl through some water and onto the next bum. The thing I find interesting there is that the Ancient Greeks had extremely limited medical knowledge alongside practices like this. And they also lived through less than pleasant times, yet they were often also quite long lived as a quick perusal of your Philosophacrates of choice can readily demonstrate. There's certainly a literal survivorship bias there, but the ubiquitousness of longevity is, if nothing else, interesting. Certainly many of these individuals would have still left their mark had they died at 40 or 50 instead.

moreira 4y ago
It seems like it’s about statistics, more than anything. Some people can be sedentary and smoke their whole lives and eat lard non stop and still live to be 80. Doesn’t mean any of that helped them in any way. It’s like that for them, too; regardless of their sanitary practices, some people will live to be old. On its own I don’t think it says much about their effectiveness. Long-lived people have always existed. The difference is in the % of people that make it that far.
- somenameforme 4y ago
  That's exactly what I was hitting on. Ancient Greeks living to quite old age were not statistical outliers, but the norm! The only way to explain this with contemporary understanding is to suggest it's just an extremely large survivorship bias, but that seems to difficult to swallow because many of those we know of from Ancient Greece we would likely still know of even had they died decades earlier as well. This [1] study looked at the mean age of Greeks "of renown" from the 5th and 4th century and found the average life expectancy was 71.3 years! There's certainly a class bias, but when we're speaking of times of antiquity all the money it world couldn't buy you what didn't exist. So all that bias would represent is, at best, more or less secure access to food, drink, and other basic necessities. [1] - https://pubmed.ncbi.nlm.nih.gov/18359748/ https://pubmed.ncbi.nlm.nih.gov/18359748/

deleted 4y ago

[deleted]

infologics 4y ago

[dead]

rawoke083600 4y ago

I'm waiting for the "designer fecal supplements". i.e fecal transplants.

kewrkewm53 4y ago

I wonder how much of the fast increasing prevalence of gut-related diseases like IBS can be explained by the changes in gut microbes, and how much is just about lack of exercise and changes in diet. Whenever I go work at relative's farm my stomach seems to work way better, even though I do plenty of exercise in my home city as well. Perhaps the type of manual labor is better for stomach than gym/running, but I wouldn't rule out the impact of microbes either.

benknight87 4y ago

I really enjoyed reading Fiber Fueled which basically lays out how all the latest science links our overall health very closely to the health and diversity of our microbiome. It will be interesting to see if new research continues to find evidence to support this. It's also a pretty convincing scientific argument in support for plant-based diets which, conveniently, is good for the planet and animal welfare as well.

qwerty456127 4y ago

> “perhaps we can restore them with probiotics.” Really? AFAIK probiotics, as well as antibiotics, can only affect the gut microbiome temporarily - it will restore to the baseline (defined in early childhood) if left alone and given some time. Isn't it so?

dragonwriter 4y ago
> AFAIK probiotics, as well as antibiotics, can only affect the gut microbiome temporarily - it will restore to the baseline (defined in early childhood) if left alone and given some time. Isn't it so? Seems to be more complicated, and differ for different types of bacteria in the gut microbiome. https://www.embl.org/news/science/gut-microbiome-changes-over-time/ https://www.embl.org/news/science/gut-microbiome-changes-ove...

tomcam 4y ago

I found them in the seat of an Uber during spring break

db1234 4y ago

Could this explain trends like increasing food allergies in countries where more and more people are becoming urban dwellers?

epgui 4y ago
It's not impossible, and it might even be plausible... But it's a really, really difficult question. People outside of science: don't make the mistake of thinking that scientists haven't thought about this before! haha
- bejelentkezni 4y ago
  What is that supposed to mean?
  - monocasa 4y ago
    That it's certainly a valid thought with the information we have, and is being thought about, but requires further investigation to make an affirmative statement.
    - deleted 4y ago
      [deleted]
    - epgui 4y ago
      ^ This is the best explanation of what I meant.
  - timfsu 4y ago
    Guessing that this means there are a lot of confounding variables other than gut biome (environment, diet, genetics, etc) that are very difficult to isolate to prove causation, as opposed to correlation.
    - K0SM0S 4y ago
      Gut biome being one of the most promising area of research, whose earth-shattering potential is about on par with the sheer complexity of the problem. If you thought ML was difficult, try modeling a human being's digestive tube from mouth to anus down to the cell: welcome to a category of problems where climate and gravity are the "simple" ones. On the other side of that space though, potentially the promise to increase by orders of magnitude our mastery of human condition both biologically and experientially.

lbeltrame 4y ago

About ten years ago my former PI (second author in the below paper) did quite a job on this in Burkina Faso, analyzing the composition of the gut in children living outside cities, in cities, and a comparison with European children. Obligatory disclaimer: I was working in his laboratory at the time, but I wasn't involved in that research. https://www.pnas.org/doi/10.1073/pnas.1005963107 https://www.pnas.org/doi/10.1073/pnas.1005963107

jonny_eh 4y ago
What's a "former PI"?
- sieabahlpark 4y ago
- chronometry888 4y ago
  The private investigator with whom you have severed ties.
- vanattab 4y ago
  principal investigator
- trollied 4y ago
  “The person(s) in charge of a clinical trial or a scientific research grant. The PI prepares and carries out the clinical trial protocol (plan for the study) or research paid for by the grant. The PI also analyzes the data and reports the results of the trial or grant research. Also called principal investigator.”
- deleted 4y ago
  [deleted]
- alienchow 4y ago
- etiam 4y ago

goatcode 4y ago

>people in U.S. cities...people in less developed parts of the world What about people in the US who are not in cities? That's the more interesting comparison to me. Why would that be left out?

jascii 4y ago
I'm curious why that comparison is more interesting to you? I can see great value in having both data points when trying to formulate a hypothesis about what causes the decline in gut-microbes in us city folks, but I find it hard to think of a use-case for solely a urban/rural comparison without other context. (Update: I was thinking about this from a scientific perspective, ignoring the idea that people might be interested in what it means for them personally (facepalm) )
- runjake 4y ago
  Because a bunch of us don't live in the city or urban environments and we're curious.
  - jascii 4y ago
    So the interest stems from a curiosity about your own gut-microbes? That seems fair enough, I may have been overthinking this...
- goatcode 4y ago
  I shouldn't say more overall, but the difference among people who have a similar diet and circumstances, but differ by housing culture, would be interesting to observe. I'd like to see apples to apples, if indeed the theorized reason of where gut differences come from is strictly (or mostly) urban vs. rural. Is it that country people are around more dirt, or that city people have different stressors, or maybe both are included? It'd be easier to tell if other differences are eliminated, imo. I've long preferred country life, having spent roughly half of my life in cities and the other half in the country, so maybe some personal interest is there too, to be honest. I do feel a lot healthier living in the countryside, perhaps my gut has something to do with that.

samstave 4y ago

epgui 4y ago
I'm unable to verify that quote. Also, it's irrelevant, and not really true at all.
- samstave 4y ago
  - epgui 4y ago
    You're right, I don't see the humour in this. And it's not pedantic to question a misquoting when the meaning is completely different. Nor is it pedantic to question the relevance of someone's comment. I don't think this quote means what you think it means.
    - samstave 4y ago
      >>that being mindful about the language we choose to accept socially is in general radical Yeah, you're a hypocrite. I am not upset, but based on your comment history, I actually expect higher of you. "question a misquoting" <-- You didnt even get the FN quote in the first place, then attempt to make yourself all "enlightened" Give me a FN break... Your feigned self-righteous demeanor simply devalues your Truth, and I am assured that you will defend your mental superiority, regardless.. My Grandmother, would oft state: "often in err, never in doubt"
      - epgui 4y ago
        Please see the rules for commenting on Hacker News: https://news.ycombinator.com/newsguidelines.html#comments https://news.ycombinator.com/newsguidelines.html#comments

dukeofdoom 4y ago

haklport 4y ago

"Moeller and others also suggest identifying the missing microbes may be the first step toward bringing them back. “If we determine that these groups were providing important functions to keep humans healthy,” Maccaro says, “perhaps we can restore them with probiotics.” Oh really? Nice submarine for Actimel, Yakult etc.

antiterra 4y ago
Unfortunately, the most effective treatment I know of to change gut biome is bacteriotherapy via a method many people find off-putting and violating. I think, for the time being, people are much more likely to accept a probiotic.
- thematrixturtle 4y ago
  I take it you mean fecal transplants, aka inserting somebody else's feces up your rectum?
  - insamniac 4y ago
    transpoosion
zdragnar 4y ago
Well, it's either a pill, or moving out of the city, or a fecal transplant (assuming that the urban / rural divide is relevant, and not just a proxy for diet). I don't live in the city, but if I were told that I would be healthier with more of these microbes that my environment doesn't support, I'd opt for the pill.
- jgrantx 4y ago
  Doing nothing is also an option! I'm not aware of an indigestion epidemic among city dwellers. Being told to do something is not sufficient, especially when multi-billion dollar industries are behind it.