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."
the whole division of bacteria into species may be (Score:4, Interesting)
Does this mean... (Score:1, Interesting)
...I can claim my ass as a dependent?
A real user... (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.
Re:Not news (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).
And it's ever changing (Score:5, Interesting)
Re:A real user... (Score:4, 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.
Re:the whole division of bacteria into species may (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.
Re:Not news (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.
Re:Not news (Score:5, 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.
Re:A real user... (Score:4, 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.
Re:the whole division of bacteria into species may (Score:4, Interesting)
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.
What does it even mean? (Score:3, Interesting)
Re:the whole division of bacteria into species may (Score:5, Interesting)
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 [wikipedia.org]). 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.
I noticed a distinct change in mine (Score:3, 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.