Science
A Little Bit of Knowledge
You know that thing you wrote saying that the inside of a body is sterile? Well, it’s not. Without bacteria and fungus in our bodies, we wouldn’t be able to digest food. And there are more of them than there are of us. Frankly, I’m really surprised to hear something so wrong, repeated so many times in a column, from someone who professes to be “Science.”(name was here)
Ph. D. candidate, Dept. of Biology
Your assertion “Unless you’re sick, the inside of your body is sterile—free from bacteria, virus, and fungus” is patently false. In reality the number of bacteria in your gut outnumber the number of human cells in the rest of your body. I think this is important for people to know. John Mayer was (besides horrible) wrong: Your body is not a wonderland. It is an ecosystem.
The skin is essentially a giant anti-harm bag for our other organs, but the inside of the body is not sterile. The upper GI tract has loads of fungus, bacteria, and enzymes living in it that help to digest our food, do nothing, or make us really unhappy. In the lower GI hepatitis, e coli, and lots of other nasties are routinely found. Maybe when you said “the inside of your body” you meant the parts sealed inside, without direct access to the outside, like the abdominal cavity, vascular system, muscles, and so forth.
From my article:
Most of the surfaces where your insides meet the world are deep within your body, in the long tubes of the gut or the branching tree of the lungs.
So, yes. I understand the gut is filled with bacteria, good bacteria that help you digest food, create vitamins and many other useful things. Did you know if those bacteria—perfectly harmless within the gut tube—get inside the body cavity all hell breaks out? Usually the adventure ends in death, or at least a long course of strong antibiotics.
An exception you could have dinged me with? Chlamydia (well, a kind of Chlamydia) actually does grow within many people’s blood vessels.
I ache, long, wish for a question about the gut, diarrhea and the long tubes within the body. Ask. Ask!
A teaser: one of the proposed contributors to the obesity epidemic is a change in composition of bacteria in the gut—from less efficient to more efficient. Wild!
Comments (17)
Can we blame your gut bacteria for contributing to global warming?
If so, how do you intend to get us to 1990 levels by 2020?
Posted by col | January 21, 2008 8:01 AMCan we blame your gut bacteria for contributing to global warming?
If so, how do you intend to get us to 1990 levels by 2020?
Posted by col | January 21, 2008 8:01 AMOkay, my family all had a bout with vomiting and diarrhea that lasted about a week after Christmas, with plenty of gas out both ends that had a distinct sulfer tint--what could it have been? Nausea continued for several days after the vomiting and diarrhea ceased.
Is that the question you wanted?
Posted by SpookyCat | January 21, 2008 8:09 AMI'm still trying to figure out how to ask something about the Viaduct without sounding like a smug know-it-all.
Posted by Greg | January 21, 2008 8:13 AMSome people have suggested that your digestive system is actually outside your body, which makes the whole "insides are sterile" thing much more plausible.
Posted by Brandon J. | January 21, 2008 8:15 AM@5: That's a good point: the digestive system is sort of like a Klein bottle.
Posted by Greg | January 21, 2008 8:23 AMtube within a tube!
Posted by ams | January 21, 2008 9:01 AMI have a question: Can you get sick from your own shit? Or if it is in your shit already, is it too late? (seems more likely) I've had this discussion on camping trips, with regard to washing one's hands. Obviously getting shit on your hands is gross, but can you get sick from it is what I want to know...
Posted by Jude Fawley | January 21, 2008 9:12 AMI was going to say the same thing that 5 said. I remember being taught in school that any part of the body that contacts the outside world- i.e. anywhere that you could send a probe to without an incision- is not the "inside" of the body. Informally we say "insides" to refer to the stomach, the gut, whatever, but it should have been obvious that Jonathan meant "inside" in the technical sense.
Posted by erika | January 21, 2008 9:52 AMFrankly, I’m really surprised to hear something so wrong from someone who professes to be a PhD candidate in biology.
hee hee... I said "probe" :-p
Posted by erika | January 21, 2008 9:55 AMMy question is, how much does the total amount of bacteria in our bodies weigh? I heard the answer recently, but promptly forgot where and how much. I know it's a surprisingly big number.
Posted by Fnarf | January 21, 2008 9:58 AMI prefer to think of us as host bodies for other life forms that have evolved to cultivate us, much as, say, apples have cultivated humans to preserve and spread their genetic material for them.
A Klein bottle would be exactly the wrong thing to compare with our bodies: it has only one side. More like, topologically, a donut.
Posted by elenchos | January 21, 2008 10:07 AMSweet, delicious juicy apples, I give in to your cultivating.
Mmmmmmmmmmmmmmmm.
Posted by Me | January 21, 2008 10:11 AMI've heard of something called leaky gut syndrome where your poo starts leaking toxins through your intenstine walls into the rest of your body. Is this true?
Posted by Gracie | January 21, 2008 10:11 AMThe interior of the body--even excluding those lumens that are contiguous with the outside--is not sterile.
Posted by Ken Callicott | January 21, 2008 10:25 AMConsider the numerous viruses that hide out within our cells. I could see excluding herpes from the discussion on the grounds that the person is sick, altough that is problematic both from the number of people infected with a herpes virus and from the percentage of time people are symptomatic. But there are others, like the polyoma viruses, that very rarely cause disease yet occur in high frequency among healthy individuals. Taguchi et al. (1982) found 96% of childen under 10 (n=384) to have antibodies to BK or JC virus. Like herpes viruses, these infections are for life. Yes, these viruses are primarily found in endothelial cells of the gut and kidneys, but they've also been found in nerve cells in healthy individuals.
There is also evidence that we're carrying around Viable But Non-Culturable (VBNC) eubacteria in our blood. See, for example, Nikkari et al. (2001) or McLaughlin et al. (2002). I don't know if anyone's looked carefully for Archaea, but clearly "sterile" isn't the appropriate description.
McLaughlin, R.W., H. Vali, P. C. K. Lau, R. G. E. Palfree, A. De Ciccio, M. Sirois, D. Ahmad, R. Villemur, M. Desrosiers, and E. C. S. Chan. 2002. Are there naturally occurring pleomorphic bacteria in the blood of healthy humans? J Clin Microbiol 40: 4771-4775.
Nikkari, S., I. J. McLaughlin, W. Bi, D. E. Dodge, and D. A. Relman. 2001. Does blood of healthy subjects contain bacterial ribosomal DNA? J Clin Microbiol 39: 1956-1959.
Taguchi, F., J. Kajioka, and T. Miyamura. 1982. Prevalence rate and age of acquisition of antibodies against JC virus and BK virus in human sera. Microbiol Immunol 26: 1057-64.
Not only is the interior of the human body not sterile, but you can scrub and scrub and scrub and never be rid of the stains.
Posted by NapoleonXIV | January 21, 2008 11:54 AMThe only thing about bodies that freaks me out is when people get some sort of fungus growing inside their brains, or someplace.
Yep, your GI tract is fulla shit & microbes & nasties. As long as they stay there I'm okay. When weird fungi decide to grow inside my brain I draw the line. Google it...
Posted by Dr_Awesome | January 21, 2008 12:36 PMComments Closed
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