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Medicine Science

Every Man Is an Island (of Bacteria) 193

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."
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Every Man Is an Island (of Bacteria)

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  • by Iamthecheese ( 1264298 ) on Tuesday January 27, 2009 @07:46PM (#26631171)
    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)
    • Re: (Score:2, Informative)

      Agreed but only under the condition that I can't read the article because it's been slashdotted.

      Anyway, different pathogenic bacteria have certain antibacterial medicines that they're susceptible to and others that their not. Ergo, division of bacteria into separate species is not overused but necessary.

      • Agreed but only under the condition that I can't read the article because it's been slashdotted.

        You say that like it matters.... ?

    • by FlyingBishop ( 1293238 ) on Tuesday January 27, 2009 @08:19PM (#26631629)

      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.

      • by duh P3rf3ss3r ( 967183 ) on Tuesday January 27, 2009 @09:35PM (#26632559)

        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.

      • by Estanislao Martínez ( 203477 ) on Tuesday January 27, 2009 @11:45PM (#26633857) Homepage

        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.

    • Bacteria, humans are simply methods by which genes replicate.


    • by jotok ( 728554 )

      I think it makes perfect sense for two reasons.

      One, my impression has always been that noting species is about aggregation, not division--that these specific organisms were all in one class even though they had superficially different species.

      Two, say you are able to further separate them based on features but you get some absurdly high number of "species." What does this do for you, exactly? The idea of "species" is a useful tool, but I think when there are a trillion trillion species each with one membe

  • 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?
    • Re: (Score:2, Funny)

      by Anonymous Coward
      Yes: Frrrrrrp.
    • Re:Crohn's Disease (Score:5, Informative)

      by ColdWetDog ( 752185 ) * on Tuesday January 27, 2009 @08:47PM (#26631969) Homepage

      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.

      • It's been a while since I've studied this, but last time I read up on it, I thought people had found a pretty strong association between prenatal measles exposure and development of Crohn's disease, and there was at least some evidence that Crohn's was a chronic focal measles infection of the intestinal system, that the immune system didn't see because it had matured after the infection was established.
        Although when I go do some reading, it looks like the infliximab-like stuff they've used to treat Crohn's

    • IBD is almost certainly influenced by gut bacteria. Once intenstinal bacteria are fully understood, it would be reasonable to expect either a cure or a highly effective treatment for IBD.

    • by J05H ( 5625 )

      absolutely. we just don't have the answers yet.

  • Hey. (Score:4, Funny)

    by Anonymous Coward on Tuesday January 27, 2009 @07:53PM (#26631267)

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

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

      The AC is probably lying
      /I learned that from an episode of House too

      • I also watch too much House, it has gotten to the point that when somebody sneezes, instead of, "Bless you!", I say, "It could be Lupus" :oD

    • by flitty ( 981864 )
      This information could have been useful to me BEFORE i used my transporter pod! Now, I live in my girlfriends lower intestine, a Hideous half-man/half-bacteria, and she's afraid that she might be giving birth to an amoeba sometime soon.
  • Our located? (Score:2, Insightful)

    by reSonans ( 732669 )

    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.

    • I'd suggest their's more two it then just playing lose with homonyms and we should call a spayed a spayed and sea it four what it is (illiteracy). But than, some won wood insist that its all rite. They new what was meant when they red it.

  • A real user... (Score:5, Interesting)

    by Anonymous Coward on Tuesday January 27, 2009 @07:56PM (#26631323)

    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.

    • Re:A real user... (Score:4, Interesting)

      by Jabbrwokk ( 1015725 ) <(moc.liamg) (ta) (nitnekraw.j.tnarg)> on Tuesday January 27, 2009 @08:19PM (#26631621) Homepage Journal

      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.

    • Re:A real user... (Score:4, Informative)

      by Anonymous Coward on Tuesday January 27, 2009 @08:22PM (#26631657)

      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.

    • Re:A real user... (Score:4, Interesting)

      by Spatial ( 1235392 ) on Tuesday January 27, 2009 @08:54PM (#26632041)

      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.

      • I recall reading about that here a few years ago, but I couldn't find any more information on it when I searched a few months back.

        This topic reminds me of Bruce Sterling's Bitter Resistance [], an entertaining and informative article about bacteria. That sounds like marketing-speak, so here's a topical excerpt:

        Bacteria live on and inside human beings. They always have;
        bacteria were already living on us long, long before our species became
        human. They creep onto us in the first instants in which we are held to
        our mother's breast. They live on us, and especially inside us, for as long
        as we live. And when we die, then other bacteria do their living best to
        recycle us.

        An adult human being carries about a solid pound of commensal
        bacteria in his or her body; about a hundred trillion of them. Humans have
        a whole garden of specialized human-dwelling bacteria -- tank-car E. coli,
        balloon-shaped staphylococcus, streptococcus, corynebacteria,
        micrococcus, and so on. Normally, these lurkers do us little harm. On the
        contrary, our normal human-dwelling bacteria run a kind of protection
        racket, monopolizing the available nutrients and muscling out other rival
        bacteria that might want to flourish at our expense in a ruder way.

        But bacteria, even the bacteria that flourish inside us all our lives,
        are not our friends. Bacteria are creatures of an order vastly different
        from our own, a world far, far older than the world of multicellular
        mammals. Bacteria are vast in numbers, and small, and fetid, and
        profoundly unsympathetic.

  • by reverseengineer ( 580922 ) on Tuesday January 27, 2009 @07:58PM (#26631357)
    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.
  • by idontgno ( 624372 ) on Tuesday January 27, 2009 @08:10PM (#26631509) Journal
    I'll have to remember that next time I get pulled over for driving "alone" in the high-occupancy vehicle lane.
  • by StuartFreeman ( 624419 ) on Tuesday January 27, 2009 @08:19PM (#26631617) Homepage
    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.
    • Re: (Score:3, Informative)

      by SlashBugs ( 1339813 )
      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 alwa
    • Re: (Score:3, Funny)

      by Genda ( 560240 )

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

    • 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 Progr

  • ....with a nice alternative to fingerprints....

  • We conceive of the individual animal as a small world, existing for its own sake, by its own means. Every creature is its own reason to be. All its parts have a direct effect on one another, a relationship to one another, thereby constantly renewing the circle of life; thus we are justified in considering every animal physiologically perfect. Viewed from within, no part of the animal is a useless or arbitrary product of the formative impulse (as so often thought). Externally, some parts may seem useless bec

    • That's just sophistry. Every animal is "physiologically perfect?" Only if your definition of perfect is meaningless...

  • by mosb1000 ( 710161 ) <> on Tuesday January 27, 2009 @09:56PM (#26632773)
    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.
    • Re: (Score:3, 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

    • What does it even mean to break bacteria up into species? They don't reproduce sexually

      Hmm... Kingdom, Phylum, Class, Order, Family, Genus, Species ... then Cell Type, Virus Type, Record industry representatives and eBay'd WoW account holders.

  • In a way this validates some claims by my ex wife in regards to my personal hygiene.
  • from the actual abstract written by the scientists:
    each person's gut microbial community varies in the [species present]..... However, there was a wide array of shared microbial genes among sampled individuals, comprising an extensive, identifiable 'core microbiome' at the gene, rather than at the organismal ..level.
    Obesity is associated with ...[changes]. These results demonstrate that a diversity of organismal assemblages can nonetheless yield a core microbiome at a functional level, and that deviations f

  • About 3 years ago, I had a terrible meal. Cheeseburger with broiled spinach topping.

    That's not the gross part.

    I had the diarrhea as I have never had before. It took more than a week for me to keep anything from going through me in an hour or less. But let's not make this alt.gross...

    Before that, I had no serious digestive problems. Never constipation for more than a day, nothing to complain about. My wife hated that, she has her issues.

    Since then, however, my digestion is different. In almost every wa

      • by ledow ( 319597 )

        I'll ask you too, just to get a straw poll going here:

        Have you ever suffered from appendicitis or had your appendix removed? If so, was this before or after this incident?

    • by ledow ( 319597 )

      Just as a query: Have you ever suffered from appendicitis?

      Current theory has it that the appendix is used to "reboot" the gut flora after illness.

      • Had mine out when I was 5.

        • by ledow ( 319597 )

          I wonder, then, if this was a factor. If you had an appendix, the current theory goes, then it would contain and isolate some of those gut flora that existed before you got ill. Thus, when you were ill enough to have to re-populate the gut, the appendix would have re-populated it with the same (or similar, or a subset of your original) flora.

          It's being touted only as a possibility but in completely unscientific, anecdotal evidence, the few people I have heard of with similar complaints had their appendix

    • Try one of the better probiotic [] supplements. Align [] is the one doctors usually recommend, if they've heard about probiotics at all, but Jigsaw's is more complete. The probiotics sold at most chain stores are worthless.

      Go easy on wheat and dairy. Gluten and casein (wheat and dairy proteins) are very hard to digest. Digestive enzyme supplements can help.

      Go easy on refined sugar. That feeds all sorts of bad things. Fake sugar (Aspartame) is bad too. Forget about soft drinks.

      Steel cut oats help.

  • ... I just have more aggressive bacteria in my gut.

Don't tell me how hard you work. Tell me how much you get done. -- James J. Ling