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Every Man Is an Island (of Bacteria)

Shipud writes "There are ten times more bacterial cells in our body than our own cells. Most of them are located in our guts, and they affect our well-being in many ways. A group at Washington University has recently reported that although our gut microbes perform similar functions, it appears that different people have completely different compositions of gut bacteria: every man is an island, a unique microbial ecosystem composed of completely different species. One conclusion is that the whole division of bacteria into species may well be over-used in biomedicine."

41 of 193 comments (clear)

  1. the whole division of bacteria into species may be by Iamthecheese · · Score: 3, Interesting

    overrated? That doesn't even make sense. Even if the features of most colonies bacteria are completely unique, that would only indicate a requirement even deeper seperation by individual feature. (i.e. metabolization of a particular substance into sugar by using a particular amino acid reaction)

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  2. Hey. by Anonymous Coward · · Score: 4, Funny

    I already learned this from an episode of House last year.

  3. Re:can anyone explain this with actual science? by the_humeister · · Score: 5, Informative

    Each of your cells takes up 100-1000x more space than bacteria.

  4. Re:can anyone explain this with actual science? by Anonymous Coward · · Score: 4, Informative

    Prokayrotic (most bacteria) cells are much much smaller than Eukaryotic (your body) cells. Therefore event though you have less cells, those cells you do have weigh much more.

  5. Our located? by reSonans · · Score: 2, Insightful

    I can't believe the summary got "affect" vs. "effect" right, and "than" vs. "then" correct, but whiffed on "our" vs. "are." That's a new one for me.

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  6. A real user... by Anonymous Coward · · Score: 5, Interesting

    Well, Im a user here, but im going anony because of my topic.

    Every man is an island: Bacteria.

    I could tell. How? Every person has a certain scent profile about them, even if they cannot smell it most of the time. I know mine when I work outside on a hot day. Some people at work also sometimes have a pronounced smell.. Perhaps its pheromones or something, I dont know. My GF also has one (and no, I dont mean vaginal smell). Like I said, this is one of the reasons why Im being a coward.

    Now, why do I know? I had a diarrhea about 2.5 months ago, from being food-poisoned at our local Subway (friend at same, same sickness, assumed food). Standard food poison is vomiting and diarrhea, neither are which are fun in the least. Along with that are heavy sweats. However, I smelled something weird: when I went to #2, I smelled an acrid smell of the faint "pheromone" I normally smell.. It was like whatever bad food I had was killing off all my good bacteria, and I was smelling it.

    So yes, I can understand Island of bacteria comment. I could also see linking the specific bacteria to weight gain/loss, BO factor, and other things. It would be neat to see a culture test of healthiness based upon non-self cultures, and perhaps inoculate yourself with other bacteria to aid in true digestion.

    Back in the 80's in OMNI, there was a toothpaste on the market for about 1 month before being pulled, that had a plaque bacteria that could not digest teeth (made no cavities). Of course, gross factor was high and was summarily pulled from market...Perhaps they were right, just 20 years too early.

    1. Re:A real user... by Jabbrwokk · · Score: 3, Interesting

      a plaque bacteria that could not digest teeth (made no cavities). Of course, gross factor was high and was summarily pulled from market...Perhaps they were right, just 20 years too early.

      Now, they would just have to spin it right ("Pro-biotic! No artificial whiteners! Organic ingredients!") and they could make millions.

    2. Re:A real user... by Anonymous Coward · · Score: 4, Informative

      Bacteria do not digest your teeth. They eat the sugar that you consume. It's their #2 (as you called shit) that dissolves the enamel on your teeth.

    3. Re:A real user... by Spatial · · Score: 3, Interesting

      Back in the 80's in OMNI, there was a toothpaste on the market for about 1 month before being pulled, that had a plaque bacteria that could not digest teeth (made no cavities). Of course, gross factor was high and was summarily pulled from market.

      I heard that something like this is being going through human trials right now; a strain of bacteria that replaces the current kind entirely, populating your mouth but not causing caries or other dental complications. For our children the phenomenon may happily be a thing of the past.

  7. Re:can anyone explain this with actual science? by Qzukk · · Score: 5, Informative

    Bacteria are a tiny fraction of the size of your cells.

    http://www.cellsalive.com/howbig.htm has a nifty little flash movie demonstrating the size difference.

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  8. With Deepest Apologies to John Donne by reverseengineer · · Score: 5, Funny

    No bacterium is an island, entire of itself; every bacterium is a piece of the intestine, a part of the main. If a Lactobacillus be washed away by the sea, the colon is the less, as well as if an Escherichia were, as well as if a colony of thy friend's or of thine own were: any bacterium's death diminishes me, because I am involved in the gut biota, and therefore never send to know for whom the bell tolls; it tolls for thee.

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  9. Re:Not news by nbauman · · Score: 2, Insightful

    Many /. readers never took biology, or if they did they were drunk or stoned when they came to class.

  10. Re:Not news by AvitarX · · Score: 5, Interesting

    I heard about it in the radio (assuming it was the same research, I heard it about 2 weeks ago), and what I found interesting was the caloric intake for different foods was dramatically different for different people (based on stomach biology).

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  11. So, I'm a self-propelled ecosystem... by idontgno · · Score: 2, Funny

    I'll have to remember that next time I get pulled over for driving "alone" in the high-occupancy vehicle lane.

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  12. And it's ever changing by StuartFreeman · · Score: 5, Interesting

    I heard a piece about this on NPR about a month ago.  What I found very interesting was that the bacteria help you to digest foods, so one person's personal bacteria may allow her to receive more energy from say a piece of pizza than another person with different bacteria.  Also very interesting was that by traveling and eating food from different regions you can pick up different bacteria and possibly gain even more energy from the foods you eat.

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    1. Re:And it's ever changing by SlashBugs · · Score: 2, Informative

      Yes, and changing the population of gut bacteria in mice can control whether the mice stay thin or get fat.

      Briefly, mice with no gut bacteria were innoculated with bacteria from either obese or lean mice. The animals given bacteria from obese mice got fat, the animals given bacteria from lean mice stayed thin. There's a good writeup here.

      The details for humans aren't known, but it seems likely that it's basically the same for us. I used to know a guy who worked on classifying gut bacteria. He was always desperate for samples so almost all of his friends had, at some stage,kept a food diary then provided him with a turd in a box to work on. It's important work, but we were all secretly afraid that our samples were actually going into the construction of some sort of shrine...

      Also: farts are gas released by your gut bacteria, not directly from you. So if you have a particularly deadly brand it's not your fault, it's your bacteria.

    2. Re:And it's ever changing by Genda · · Score: 2, Funny

      Though I would also recommend boiling the water in Tijuana, the additional bacteria you pick up there will not give you more energy...

  13. Re:the whole division of bacteria into species may by FlyingBishop · · Score: 4, Interesting

    In terms of the animal kingdom, the concept of 'species' may easily be understood in terms of the concept of breeding. When two organisms cannot produce fertile offspring, they are separate species. This is a well defined barrier. A population does not become a new species overnight.

    In terms of bacteria, they can become what might be termed a new species overnight. In the case of this article, they're noting that though the bacteria may be dissimilar at a genetic level, at a morphological level they are essentially the same, hence the question of the value of the species idea. We all have different species of bacteria living inside of us, but they all do the same basic things.

  14. Re:Not news by Shipud · · Score: 5, Interesting

    Common knowledge you can find in most microbiology or immunology textbooks.

    Quite the opposite. What you would find in most textbooks is the assumption that there is a core human gut microbiome common to whole human populations. The Nature article refutes this. There are millions of $ being put into sequencing the human core gut microbes, but apparently there are no core gut microbes, and this human microbiome sequencing strategy needs rethinking.

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  15. Re:Crohn's Disease by Anonymous Coward · · Score: 2, Funny

    Yes: Frrrrrrp.

  16. Re:Not news by philspear · · Score: 4, Interesting

    Indeed, and this is an understatement. I've been told that the reason dogs can track you by smell is not so much that your OWN cells produce a unique smell, it's more that they're actually smelling your unique bacterial garden growing on your body. Which is also why they need fairly fresh clothing or scent, it changes over time. Another interesting tidbit I was told in microbiology class: every time you made out with someone, you probably picked up new SPECIES of bacteria in your mouth. Of course, he was talking to a classroom of college students, maybe that's not true for dating in a senior center.

    Note that I'm not saying that I myself have so much as wiki'd this information. But if this is new knowledge, I've been massively lied to.

  17. Re:yes, size does matter by professionalfurryele · · Score: 2, Funny

    And so the legend of torso boy continues... He may only be .4 of a boy, but he's 110% heroic, in this weeks episode... Sorry that made me chuckle.

    You are probably right, although in the context of test scores I'm not convinced. My stats are right even if my knowledge of what people are thinking when they say stuff sucks.

  18. Re:Crohn's Disease by ColdWetDog · · Score: 4, Informative

    I've heard it speculated that this could be one of the causes of Crohn's Disease and Colitis. Can anyone here comment on this?

    Sure, it's possible: We know that Crohn's / Ulcerative Colitis have genetic predisposition - it's certainly possible that a susceptible person's immune system sees a particular bacterium or portion thereof or byproduct thereof and starts down the pathway of an autoimmune phenomenon.

    In light of the nature of the pathologic findings in Crohn's disease (see later) and ulcerative colitis, it has long been clear that IBD represents a state of sustained immune response. The question arises as to whether this is an appropriate response to an unrecognized pathogen or an inappropriate response to an innocuous stimulus. Over the decades, many infectious agents have been proposed as the cause of Crohn's disease including Chlamydia, Listeria monocytogenes, cell wall-deficient Pseudomonas species, reovirus, and many others. Paramyxovirus (measles virus) has been implicated etiologically in Crohn's disease as a cause of granulomatous vasculitis and microinfarcts of the intestine[30]; a proposed association between early measles vaccination and Crohn's disease has been largely disproved.[31] Another suggestion has been that the commensal flora, although normal in speciation, possess more subtle virulence factors, such as enteroadherence, that cause or contribute to IBD.[32]

    Among the most enduring hypotheses is that Mycobacterium paratuberculosis is the causative agent of Crohn's disease. This notion dates to Dalziel's observation in 1913 that idiopathic granulomatous enterocolitis in humans is similar to Johne's disease, a granulomatous bowel disease of ruminants caused by M. paratuberculosis.[33] M. paratuberculosis is extremely fastidious in its culture requirements, and some proponents of this hypothesis have speculated that the presence of M. paratuberculosis as a spheroplast may confound efforts to confirm the theory. Efforts to confirm this theory have included attempts to culture the organism; demonstrate it by immunohis-tochemistry, in situ hybridization, and polymerase chain reaction methodology; and empiric treatment with antimycobacterial antibiotics. Most investigation in this area has been inconclusive, providing insufficient evidence to either prove or reject the hypothesis.

    from Feldman: Sleisenger & Fordtran's Gastrointestinal and Liver Disease, 8th ed.

    So sure, maybe. Stay tuned.

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  19. Re:Not news by LaskoVortex · · Score: 4, Funny

    There are millions of $ being put into sequencing the human core gut microbes, but apparently there are no core gut microbes, and this human microbiome sequencing strategy needs rethinking.

    What this paper means is that you can spend billions of dollars sequencing the gut bacteria of thousands of different people and never get the same Nature paper twice. It also means that the number of boring "we sequenced everything we could find" papers in Nature and Science is going to skyrocket from what is already too many.

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  20. Re:Not news by LaskoVortex · · Score: 4, Insightful

    Another interesting tidbit I was told in microbiology class: every time you made out with someone, you probably picked up new SPECIES of bacteria in your mouth. Of course, he was talking to a classroom of college students, maybe that's not true for dating in a senior center.

    You have obviously never dipped your pen in senior center ink, my friend.

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  21. Re:Not news by snowraver1 · · Score: 2, Funny

    Let's hope so...

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  22. Re:back to the past by Shipud · · Score: 2, Insightful

    Every man is an island

    and obviously, the summary was written in the 40s, before feminist criticism of language became familiar to the mainstream.

    Obviously, you did not recognize the John Donne reference.

    --
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  23. Re:the whole division of bacteria into species may by duh+P3rf3ss3r · · Score: 4, Interesting

    In terms of the animal kingdom, the concept of 'species' may easily be understood in terms of the concept of breeding. When two organisms cannot produce fertile offspring, they are separate species. This is a well defined barrier. A population does not become a new species overnight.

    This is an incredible oversimplification, especially when you realise that asexual reproduction is very common in the animal kingdom. The idea you quote is often cited but is, in itself, an insufficient criterion. For example, there are organisms which can interbreed and can produce fertile offspring that are clearly considered separate species by any objective measure. In many species, lots of individuals are incapable of interbreeding with lots of individuals of the same species. Interbreeding is a complex thing that synthesises anatomical, behavioural, geographical and genetic components. A failure in any of these can cause a failure to interbreed which does not necessarily equate to a different species. There are also complexes of closely related species that interbreed frequently and produce fertile offspring but they are still distinct species.

    In any case, TFA is about bacteria and not animals. The principle of using inability to interbreed as a definition of species in animals is even more removed from reality in bacteria which often share genetic material across species, even species that are not closely related.

    Finally, the postulate that two creatures that are functionally similar within a diverse community, despite genetic dissimilarity, might not be considered different species is simply ludicrous. For example, in fish community assemblages, there are normally planktivores and piscivores. From a broad community perspective, the top-level piscivores all perform precisely the same function. No one, however, would argue that that makes them the same species. By way of illustration, the lake trout in a salmonid/coregonid community fulfills the same functional role as the northern pike in an esocid/coregonid community. That doesn't make lake trout and northern pike the same species.

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  24. Re:Not news by Nimloth · · Score: 5, Insightful

    I would say the fact that you keep vomitting might be what's making you skinny, not the bacteria in your gut.

  25. Re:Not news by Missing_dc · · Score: 4, Funny

    Since most of the useful bacteria likely live lower in the digestive system, eating your shit might be more productive for those unfortunate people.

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  26. What does it even mean? by mosb1000 · · Score: 2, Interesting

    What does it even mean to break bacteria up into species? They don't reproduce sexually. They take up new genetic material from their environment. It's a bit of a misnomer.

    1. Re:What does it even mean? by smellsofbikes · · Score: 2, Informative

      Basically, species classifications are ambiguous and fuzzy even in higher animals, but they've served us really well as modelling tools, much like Newtonian physics, so we apply them everywhere. As long as we keep it in mind that they're not necessarily accurate, it's a fine idea.
      With that said, there are characteristics that are unique to some species of bacteria, and shared by all members of that species. It's not a terrible approximation. All Clostridium species are anaerobic, for instance. So if you have a huge population of bacteria, and you divvy them all up according to a whole raft of tests -- aerobic/anaerobic, gram+/gram-, pili/no pili, sporulating/nonsporulating and so forth -- at the end you have a whole bunch of groups, and within each group you find an extremely high similarity in DNA sequence, much more similar than a member from a different group. It's not a terrible idea to call that a species, even if it might not mean exactly the same thing that we mean when we apply the term to animals.

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  27. Re:Not news by Anonymous Coward · · Score: 2, Funny

    >>I heard about it in the radio

    What kind of radio do you have? Sadly, I can't fit into mine.

  28. Re:can anyone explain this with actual science? by Anonymous Coward · · Score: 2, Informative

    Um, most of your body weight is water. And water is not cells :)

    Actually, the vast majority of the water in your body is found inside your cells, so in fact water IS cells (or rather cells ARE water)

  29. Re:the whole division of bacteria into species may by Estanislao+Mart�nez · · Score: 5, Interesting

    In terms of the animal kingdom, the concept of 'species' may easily be understood in terms of the concept of breeding. When two organisms cannot produce fertile offspring, they are separate species. This is a well defined barrier.

    Um, no, it is not. One simple initial example to get the ball running: there are hybrids where the males are sterile, but the females are fecund; for example, hybrids of domestic cats with the African serval (the resulting hybrid is called a Savannah cat). Since a housecat and a serval can produce fertile offspring, your test fails to establish them as separate species. (Note that I was careful not to say that the fertile offspring proves that they are the same species, "If A then B" doesn't entail "If B, then A.")

    Now, you may be thinking of ways of strengthening your definition against examples like this one, but that was only the starting point. The broader problem is that as you try to come up with more and more precise definitions of "species," all you will do is set yourself up for ever more elaborate examples of intermediate cases that either pose a problem for your definition, or just suggest that your definition makes arbitrary, unprincipled decisions about where the line should lie. (E.g., what if there are two types of organisms that produce infertile offspring 25% of the time? 12.5%? 7.25%? How low must the percentage get to prove a species barrier? Must that number be the same for every pair of organisms, or does it make sense to measure it differently for different pairs because of some fact about genetics? What about pairs of organisms that would produce fertile offspring often enough, but are reproductively isolated by geographical boundaries? Etc.)

    The deeper point is that evolution doesn't care about "species"; it cares about populations whose members interbreed, and in the real world, such populations may easily have very vague boundaries, because "X can breed with Y" isn't a yes/no matter.

  30. Re:Not news by Daniel+Dvorkin · · Score: 3, Informative

    "Common knowledge you can find in most microbiology or immunology textbooks" doesn't generally get a publication in Nature.

    I've worked with one of the authors (Rob Knight) of the most recent paper, so I have some idea of what their research entails. Basically they were expecting to find some diversity in bacterial populations between individuals, but the amount they found was the big surprise -- there is more genetic diversity between the gut bacteria population of any two randomly selected people than there is between two soil bacteria populations in a deep sea trench and on a mountaintop! How strongly the bacterial populations predict leanness vs. obesity was also far beyond any previously published result.

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  31. I noticed a distinct change in mine by snowwrestler · · Score: 2, Interesting

    A couple years ago I got very, very sick--nastiness coming out of both ends to the point of hospitalization for dehydration. It took a week for my abdominal muscles to get over the soreness from the heaving. Before that sickness, I had a very tolerant digestive system--spicy, rich, or strange foods did not bother me at all. Since the sickness, certain foods upset my digestive system, causing gas, bloating, etc. And it's weirdly specific--I used to love Progresso canned soup, but since the sickness any Progresso soup with chicken in it gives me terrible gas.

    This article is really interesting because I was just speculating the other day with my wife about this--that maybe my sickness cleaned out my GI system so thoroughly that I've lost certain gut bacteria that I had collected over the course of my life, and thus I'm not able to digest certain foods as easily as I once could.

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  32. Re:the whole division of bacteria into species may by killtherat · · Score: 4, Informative

    Something doesn't make sense:

    There are ten times more bacterial cells in our body than our own cells. Most of them are located in our guts

    That means that over 50% of 90% of our body mass in in our guts? Well, the researchers are Americans...

    It's because microbial cells are much smaller then eukaryote cells. Imagine a bunch of basket balls surrounded by BBs.

    By mass its probably about two pounds.

  33. Re:Bacteria and weight by spazdor · · Score: 2, Informative

    Human tissue cells routinely outweigh bacterial cells by more than 100 to 1.

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  34. Re:Not news by camperdave · · Score: 4, Funny

    You have obviously never dipped your pen in senior center ink, my friend.

    Only seniors and calligraphers use pens that you need to dip into ink. The rest of us use ball points or cartridge driven quills. Quick to use, they are ready at a moment's notice. They are far less messy and less prone to leakage. They have greater "staying power", as there is no need to go back to the well for a refill.

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  35. Re:the whole division of bacteria into species may by Anonymous Coward · · Score: 2, Funny

    And by volume it's about 3 grams.