[HN Gopher] Modern city dwellers have lost about half their gut ...
___________________________________________________________________
Modern city dwellers have lost about half their gut microbes
Author : Hooke
Score : 145 points
Date : 2022-06-30 20:37 UTC (2 hours ago)
(HTM) web link (www.science.org)
(TXT) w3m dump (www.science.org)
| lbeltrame wrote:
| 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
| aluminussoma wrote:
| How does one analyze the gut biome? I imagine it involves
| running poop through a machine - what kind of machine? I would
| love to learn more about the technical process.
| nebfield wrote:
| The paper uses 16S rDNA sequencing, which is a bit old
| fashioned now but it was a good method when the paper was
| published. The steps basically involve:
|
| 1. Extract all DNA from poop, normally using a kit that
| basically makes DNA stick to tiny plastic beads. You wash the
| beads in a bunch of different chemical solutions to isolate
| DNA from the original sample and purify it. There are a lot
| of different methods to do this.
|
| 2. Amplify a small section of DNA that's universally unique
| to bacteria and archaea which is used as a barcode. This
| barcode has some areas that change a lot across different
| species and some areas that don't change much.
|
| 3. Sequence the amplified DNA. The DNA sequencer determines
| the sequence of nucleotides in each DNA amplicon (an amplicon
| is a piece amplified piece of DNA). An example DNA sequence
| is ACCTGGCT
|
| 3. The DNA sequencer produces millions of DNA sequences in
| parallel and stores them and some metadata (e.g. quality and
| confidence measurements) in text files
|
| 4. When this paper was published, a friendly bioinformatician
| would have taken the text file and clustered the different
| sequences. Sequences 97% similar were binned together as a
| rough approximation of a species. Different taxonomic levels
| have different cutoffs, but it's all quite vague and there
| are better methods now that involve denoising sequences from
| quality measurements (e.g. dada2 method)
|
| 5. A count for each different bin is generated, and
| "representative sequences" for each bin are matched against
| taxonomic databases to see what species are present
|
| 6. Normal ecological analysis is done on the count data to
| calculate alpha and beta diversity or do other types of
| analysis. Once you have counts, it doesn't matter that the
| data are from bacteria instead of sheep or penguins
|
| Newer methods involve sequencing every single bit of DNA in a
| sample, not just a specific region. This is called
| metagenomics and it's very hard to do and requires very big
| computers and big DNA sequencers.
| ebolyen wrote:
| Great summary! Although I would argue that 16S is still a
| perfectly good (and cost-effective) method, especially with
| DADA2. There are also neat sequencing techniques that like
| CCS which give you really high resolution of a target
| region (amplicon) without sequencing a lot of
| redundant/uninformative DNA.
| feet wrote:
| Most likely extracting and culturing then PCR
|
| Edit: grabbed from the methods section. I was wrong, they
| didn't culture :)
|
| >Fecal samples were collected by physicians and preserved in
| RNAlater (Qiagen) at -80 degC until extraction of genomic DNA
| (28) (details in SI Materials and Methods).
| jonny_eh wrote:
| What's a "former PI"?
| [deleted]
| sieabahlpark wrote:
| chronometry888 wrote:
| The private investigator with whom you have severed ties.
| vanattab wrote:
| principal investigator
| trollied wrote:
| "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]
| alienchow wrote:
| 3.1415Nein
| etiam wrote:
| "Principal investigator". Roughly a research group leader.
|
| https://en.wikipedia.org/wiki/Principal_Investigator
| kkaranth wrote:
| The former "Principal Investigator" of the (research)
| project. Often the professor who is responsible for obtaining
| the grant and driving progress
| setgree wrote:
| Wow is the mobile UX of PNAS bad -- the cookie pop-up has no X
| button and if you click 'continue' -- which I thought meant
| continue to the article -- it directs you to the terms of
| service. If you press back, you see the same pop-up again.
|
| Looks like interesting research though!
| [deleted]
| Sunspark wrote:
| 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.
| thelittleone wrote:
| 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.
| olliej wrote:
| 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.
| goatcode wrote:
| >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 wrote:
| 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 wrote:
| Because a bunch of us don't live in the city or urban
| environments and we're curious.
| jascii wrote:
| So the interest stems from a curiosity about your own gut-
| microbes? That seems fair enough, I may have been
| overthinking this...
| CodeBeater wrote:
| Personal interest does not necessarily equal marginal
| utility.
| jstanley wrote:
| Even from a scientific perspective, it would be more
| interesting to see the effect of each variable independently
| (cities vs rural, US vs somewhere else) rather than bundling
| them together.
| goatcode wrote:
| 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.
| woodruffw wrote:
| > 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?
|
| At least in the US, my lay-intuition is that you wouldn't see
| much of a difference between _average_ Americans between urban,
| suburban, and rural settings. That 's perhaps worth testing,
| but I think the much more interesting test would be between
| wealth and class groups.
|
| (Again, wild speculation: it's easy to imagine that most gut
| biota don't care about the difference between dollar-store
| knockoff sodas and brand-name sodas, but _definitely do care_
| about $14 free-range, organic eggs.)
| mathgeek wrote:
| > but definitely do care about $14 free-range, organic eggs
|
| Can you elaborate on why you think this is the case?
| Intuitively to me, most folks' diets are going to be mostly
| cooked eggs which would reduce any effect on bacteria in the
| gut.
| woodruffw wrote:
| Sorry, I meant that as a proxy for "families that have the
| purchasing power to buy premium goods." My intuition is
| that there's a _weak_ inverse relationship between food
| processing and food price, with less processing
| corresponding to healthier gut biota. But you're right that
| the $14 eggs themselves probably don't matter.
| olliej wrote:
| 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 :-/]
| afarviral wrote:
| 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 wrote:
| Explore the use of Miswak for your teeth.
| samstave wrote:
| epgui wrote:
| I'm unable to verify that quote.
|
| Also, it's irrelevant, and not really true at all.
| samstave wrote:
| epgui wrote:
| 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.
| rr888 wrote:
| 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.
| prirun wrote:
| I've had good luck with these, taken one in the morning and one
| at night.
|
| 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.
| asdff wrote:
| You don't need to order more starter once you have your
| yogurt. You can use a spoonful of your last batch to start
| the next batch. I go 30 minutes at 180-190*f with the milk,
| then i let it cool to 110*f, then I add my scoop of yogurt,
| then I will hold that at 110*f in a separate container in a
| 110* waterbath (just a big pot of 110* water holding my
| yogurt tupperware containers that I periodically splash more
| hot water into) for like 8-12 hours or so (I sometimes forget
| about it on the stove...). Then I put it in the fridge for
| two days and after its good to go. If you want it to be more
| like greek yogurt you can strain it with coffee filter paper
| and use the whey liquid for various things.
| asdff wrote:
| chobani claims six strains of yogurts, I used that as starter
| for my homemade yogurt batches since then. Otherwise I try and
| get my exposure in from the environment. I'm vaccinated so I
| don't bother with the mask unless there are hard rules. I will
| avoid overusing hand sanitizer. I take crowded public transit
| and otherwise walk around sidewalks and stores with a bunch of
| people vs private car and delivery of all my needs. I do
| computer work but I do almost all of it outdoors on a patio
| table, where I am exposed to pollen and spores and microbe
| aplenty (but probably better air quality than indoors given the
| plastic off gassing in the modern home). Basically I am trying
| to inoculate myself with a wide variety of things available in
| my local environment, just like people used to be before all
| this modern society stuff locked us sitting in rooms. It seems
| to work as far as I can tell anecdotally; I can't remember the
| last time I was sick.
| trollied wrote:
| 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
| Splendor wrote:
| 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-probioti...
| cheese_goddess wrote:
| If you want variety of bacteria, then the highest is probably
| in milk kefir, and the second highest in aged, hard cheese.
|
| Kefir, we don't even know how many or what bacteria it hosts,
| but we know it's a lot. Different studies have reported wildly
| different communities, but all of them with upwards of a dozen
| species. For example:
|
| > Sequencing-Based Analysis of the Bacterial and Fungal
| Composition of Kefir Grains and Milks from Multiple Sources
|
| https://journals.plos.org/plosone/article?id=10.1371/journal...
|
| Aged hard cheese, unless made with raw milk, is usually
| inocculated with a couple of strains of lactic acid bacteria,
| but during aging a varied flora develops, of "adventitious
| bacteria" and yeasts from the environment.
|
| To be honest though, I made kefir for a couple of years and
| I've been making cheese for about four now and I make the
| occasional yogurt now and then, but I'm still not convinced
| about the health claims of "probiotics". And I'm not the only
| one to be skeptical:
|
| > A growing probiotics market has led to the need for stricter
| requirements for scientific substantiation of putative benefits
| conferred by microorganisms claimed to be probiotic.[7]
| Although numerous claimed benefits are marketed towards using
| consumer probiotic products, such as reducing gastrointestinal
| discomfort, improving immune health,[8] relieving constipation,
| or avoiding the common cold, such claims are not supported by
| scientific evidence,[7][9][10] and are prohibited as deceptive
| advertising in the United States by the Federal Trade
| Commission.[11] As of 2019, numerous applications for approval
| of health claims by European manufacturers of probiotic dietary
| supplements have been rejected by the European Food Safety
| Authority for insufficient evidence of beneficial mechanism or
| efficacy.[8][12]
|
| https://en.wikipedia.org/wiki/Probiotic
|
| Btw, you know what elese has plenty of lactic acid bacteria,
| therefore probiotics? Sourdough. Alhtough if you make kefir,
| you can use it instead of sourdough as a bread starter.
| jschveibinz wrote:
| Microbiome research at John's Hopkins:
|
| https://www.hopkinsmicrobiome.com/faq
| dukeofdoom wrote:
| haklport wrote:
| "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 wrote:
| 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.
| zdragnar wrote:
| 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 wrote:
| 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.
| bawolff wrote:
| More research is needed.
|
| However there is an obseity epidemic and a depression
| epidemic, and its plausible they are related. Which doesn't
| mean they are, but seems like something worth looking into.
| dannyperson wrote:
| The study compares humans (who happen to live in cities) to
| primates (who definitely don't live in cities). It doesn't
| compare between human populations.
| boomchinolo78 wrote:
| 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 wrote:
| can you please expand on this?
| nebfield wrote:
| 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...
| Splendor wrote:
| > ...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 wrote:
| 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.
| dagw wrote:
| 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 wrote:
| 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.
| woodruffw wrote:
| 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-...
| wheelerof4te wrote:
| The US is not the entire world.
|
| It's your fault for having undeveloped rural areas with low
| education levels.
| hahaxdxd123 wrote:
| > near non-sequitur thesis not discussed in article stated
| definitively
|
| > flimsy evidence which isn't true
| [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3365871/]
|
| Certified HackerNews moment!
| 0bfus wrote:
| > 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.
|
| Can't find it for meat in general, but it seems that rural
| areas eat significantly more beef than suburban or urban
| dwellers.
|
| https://www.ers.usda.gov/webdocs/outlooks/37388/29633_ldpm13...
| .
| sudden_dystopia wrote:
| Based on the way my body responds and reviewing lab results
| after trying different diets, I am of the opinion that it has
| more to do with processed foods versus minimally/unprocessed
| foods. I don't think whether it is plant or meat/dairy based
| really matters that much nutritionally. Enriched flour, is
| plant based but by no means do I believe that to be healthy.
| Same goes for sausage and bacon, too processed. N of 1 but
| since I stopped consuming processed food and stopped worrying
| about cholesterol while restricting calories, eating plenty of
| fruit & veggies, and exercising, I have actually lowered my ldl
| cholesterol by 40 points. Triglycerides were fine. Dr was
| thrilled, didn't have the heart to tell her I didn't follow her
| advice.
| baby wrote:
| How does probiotic helps here?
| kaycebasques wrote:
| 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 wrote:
| 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.
| subsubzero wrote:
| 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-...
| digitcatphd wrote:
| I think the consensus is nobody really knows and nutritional
| science is largely trendy pseudoscience...
| asdff wrote:
| 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 wrote:
| > 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 wrote:
| 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.
| steve_adams_86 wrote:
| 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.
| f38zf5vdt wrote:
| Seems unlikely. A lot of the traditional West African diet is
| fermented and they have the lowest rates of colon cancer on
| Earth. Smoked foods and foods containing nitrates/nitrates
| are correlated with stomach and colon cancer, but not salty
| or fermented foods. Studies that show a correlation of salt
| intake with cancer are very possibly confusing intake of
| smoked meat or processed meat (also high in salt) with colon
| cancer. For example, when adjusting for processed meat, one
| study finds that salt is not correlated at all with colon
| cancer. [1]
|
| [1] https://www.clinicalnutritionjournal.com/article/S0261-56
| 14(...
| giardini wrote:
| Eating yogurt or sauerkraut will not render you (once again)
| lactose tolerant.
|
| Lactase (the enzyme that breaks down lactose) production is
| regulated by a human gene; how would a probiotic like yogurt
| alter a gene?
|
| https://biologydictionary.net/lactase/
| etiam wrote:
| Well, as you probably know, genes are regulated more or less
| according to environmental cues all the time, including being
| very much subject to presence and behavior of
| commensals/parasites/symbionts.
|
| I don't know any specific data whatsoever about inducing
| lactase, but it seems perfectly plausible that microorganisms
| such as lactic acid bacteria could interact with the system.
| msbarnett wrote:
| This has been studied, but the results tend to argue that
| it's purely genetic, eg)
|
| https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6669050/
|
| > Studies that have measured changes in endogenous lactase
| activity after an intervention period consistently show a
| lack of enzyme induction, suggesting that lactose intake
| does not affect an individual's lactase activity. Although
| these studies are scarce and have relatively few subjects,
| data from cross-sectional studies support the theory of
| purely genetic regulation
| barkingcat wrote:
| You could always ingest other bacteria that can digest and
| break down lactose and rely on probiotics to digest the
| lactose for you instead of having a gene.
|
| That's what ruminents do anyways, you need a steady colony of
| these helpful bacteria or you lose the tolerance. While that
| seems troublesome, for many animals that's how metabolism
| works for their entire life.
| p10_user wrote:
| Epigenetic reversal of some inhibitory histone marks at the
| promoter region of the enzyme? Driven by some yet-to-be-
| discovered signaling cascade induced by reintroduction of
| lactose and proliferation of lactose loving microbes?
|
| Just spitballing, this is pure speculation, but is plausible.
| Terry_Roll wrote:
| Chlorine, chlorinated water, chlorinated (bleached) flour,
| chlorinated chickens....
|
| Which is why its consigned to the conspiracy books.
| ryanianian wrote:
| What?
| msbarnett wrote:
| > People are becoming even lactose intolerant.
|
| This isn't new, and certainly isn't some crisis of the last 100
| years. Historically only a minority of the planet has ever been
| lactase persistent into adulthood. It's a well-understood
| genetic trait, not some product of gut microbes.
| dannyw wrote:
| You can think of this being evolutionary beneficial, if some
| milk is bad, the whole village don't all get sick.
|
| Also a possible reason for why people have different taste
| preferences.
| msbarnett wrote:
| It's probably simpler than that: it's simply not energy-
| efficient to keep producing an enzyme throughout its life
| for a sugar that's rare-to-non-existent in an organism's
| diet for most of that life. Because mammals don't have any
| means of obtaining milk once they separate from their
| mother, lactose intolerance for their lifetime after
| weaning is almost universal among mammals.
|
| Humans are odd in that they harvest milk for consumption at
| all beyond our own mother's, which is probably why we're
| the only species with a notable population with the genetic
| mutation that allows some of us to digest it - there's no
| competitive advantage to that mutation in most other
| mammals, because where would they even obtain milk?
| db1234 wrote:
| Could this explain trends like increasing food allergies in
| countries where more and more people are becoming urban dwellers?
| prometheus76 wrote:
| There's a guy (Jasper Lawrence, who had a horrible allergy
| problem) had heard of a study where they were testing to see if
| allergies was related to parasites. He was rejected from the
| study, so, long story short, he ended up flying to northern
| Africa and walking around barefoot to get hookworm. He now
| monitors and manages his hookworm infection with low doses of
| anti-parasite medication, and he sells soil infected with
| hookworms so that you, too, can get infected by hookworm and
| reduce/eliminate your allergies. Oh, and his allergies are
| gone.
|
| I read about it here: https://www.ksl.com/article/20838871/man-
| infects-self-with-h...
|
| But there are lots of stories and some studies on the subject
| as well. The original hypothesis was proposed in 1989 by David
| P Strachan. According to the theory, many modern diseases have
| gotten out of hand and are rapidly growing in industrialized
| western countries because of chlorinated drinking water,
| vaccines, antibiotics and the sterile environment of early
| childhood. Moreover, it is theorized that since we have become
| so good at preventing infections, we have upset the internal
| balance and ecology in our bodies. One missing element of
| hyper-clean and sterile environments is that our inflammatory
| responses do not function as they should. Parasites and
| bacteria play a symbiotic role in preserving our health.
| noodles_nomore wrote:
| He originally posted his story on kuro5hin[1]. It's an
| interesting read. He was interested in the worm because, for
| its survival, it has evolved a mechanism to disable the
| host's immune system in a particular way that eliminates
| allergies. At the time he wrote that nobody knows how the
| worm does it. Now that we can do similar things with
| monoclonal antibodies, I wonder if the mechanism is similar.
|
| [1] http://web.archive.org/web/20151205143301/http://www.kuro
| 5hi...
| woodruffw wrote:
| Please, for the love of all that is good and holy, do not
| give yourself hookworms.
| seraphsf wrote:
| I know a person who contracted a transient parasite
| infection, possibly hookworm, while doing research in Africa
| and walking around barefoot. In the decade+ since, they've
| suffered terribly from debilitating and incurable auto-immune
| diseases brought on by the initial parasite infection.
|
| So, YMMV.
| prometheus76 wrote:
| I agree that caution is in order. The question above just
| reminded me of the story so I thought I'd pass it along
| because it was from 2012.
| CodeBeater wrote:
| I can only imagine how desperate he must have been. Truly
| debilitating levels of allergy.
| epgui wrote:
| 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 wrote:
| What is that supposed to mean?
| monocasa wrote:
| 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.
| timfsu wrote:
| 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.
| wheelerof4te wrote:
| lnxg33k1 wrote:
| Well of course it's obvious that we're not carnivorous our
| ancestors didn't eat meat and always used to go to the
| pharmacy to get their iron and B vitamin supplements
| wheelerof4te wrote:
| Plenty of both iron and vitamin B in plant-based food.
|
| You really believe we hunted big game so much? With what?
| Sticks and stones? How did we catch them with our weak
| legs? How the hell did we skin them or eat their raw flesh?
| Cooking wasn't a thing for a long time.
|
| And why don't we eat the animal meat raw? Don't you love it
| when you see the dead, rotting carcas all open and blody?
|
| I sure don't. And neither would you, unless you were
| starving in the middle of winter.
| lnxg33k1 wrote:
| I don't know I meet a lot of people that say that there
| is a lot of iron and B in plants but all the vegan I met
| working were always taking supplements, maybe if you tell
| me what are the plants with B12 and iron I can pass over
| the info next time I see one of them
| wheelerof4te wrote:
| There is abundance of iron in spinach, nettle and other
| similar plants.
|
| For the b12 needs, eat some algae or even dirt. Yes,
| dirt. Plenty of dirt on a plant's root, which ancient
| humans ate like no tomorrow.
| lnxg33k1 wrote:
| Eating dirt seems much more natural than eating animals,
| I guess they discovered the fire to cook the dirt then, i
| guess tonight I found the reason why vegans are full of
| shit :D
|
| Ps just searched for 'dirt b12' on ddg and the first
| website is an ad for b12 supplements
| fosk wrote:
| Humans used to exhaust their prey. Once the prey is
| exhausted - in the absence of better tools - pick a rock
| and hit the head of the animal until it dies.
|
| There are videos of animals (like deers) so exhausted
| they just sit there while a lion eats them alive: they
| are not moving, they are not standing up, they are just
| sitting there watching another animal eating their guts
| alive. Just like that.
|
| You can eat meat raw as long as it's fresh (just killed),
| likewise we eat raw fish as long as it's fresh. Carpaccio
| is raw meat, for example, and very popular too.
|
| We were eating less meat - for sure - since cutting and
| digesting raw meat takes longer. But I guess we were also
| eating less of everything to begin with.
| bmj wrote:
| Requisite xkcd: https://xkcd.com/1471/
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