How Bacteria in Our Bodies Protect Our Health - Scientific American
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How Bacteria in Our Bodies Protect
Our Health
Researchers who study the friendly bacteria that live inside all of us are starting to sort out who is
in charge—microbes or people?
By Jennifer Ackerman
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Biologists once thought that human beings were phys​iological islands, entirely capable of regulating their own
internal workings. Our bodies made all the enzymes
needed for breaking down food and using its nutrients to
power and repair our tissues and organs. Signals from
our own tissues dictated body states such as hunger or
satiety. The specialized cells of our immune system
taught themselves how to recognize and attack
dangerous microbes—pathogens—while at the same time
sparing our own tissues.
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Over the past 10 years or so, however, researchers have demonstrated that the human
body is not such a neatly self-sufficient island after all. It is more like a complex
ecosystem—a social network—containing trillions of bacteria and other
microorganisms that inhabit our skin, genital areas, mouth and especially intestines.
In fact, most of the cells in the human body are not human at all. Bacterial cells in the
human body outnumber human cells 10 to one. Moreover, this mixed community of
microbial cells and the genes they contain, collectively known as the microbiome, does
not threaten us but offers vital help with basic physiological processes—from digestion
to growth to self-defense.
http://www.scientificamerican.com/article/ultimate-social-network-bacteria-protects-health/
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How Bacteria in Our Bodies Protect Our Health - Scientific American
10/25/15, 1:40 PM
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BigInScience
May 15, 2012, 12:18 PM
The complex relationships between humans and bacteria are fascinating. Many are (at first)
horrified to learn that the average person possesses over 100 TRILLION bacteria (including
perhaps a billion or more E.Coli) in and on our bodies. Interestingly, our bodies frequently live in
symbiosis with these bacteria: for example, bacteria such as E.Coli in our gut synthesize Vitamin K,
a vitamin important for blood clotting. Individuals taking certain antibiotics may experience a
nearly 3/4 reduction in Vitamin K production. If you'd like to read more on fascinating topics
within science, medicine, and technology, feel free to browse my blog: http://biginscience.com/
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dr.vijay
May 15, 2012, 2:27 PM
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We could also take a different look at it. I am sure, thousands of years back we might not have had
the same microbiome. It is ever evolving. Microbes always colonize any organic living tissue for
food. And when any microbe first colonized a host, they might have been pathogens and after a
long period of fight between host and the pathogen, they co-evolved and thus might've acquired
symbiotic form of living together happily. And thus even the use of Vitamin K in hosts biological
process could've been after the microbes colonization(may be we didn't have any use for vit.K
earlier, but evolved after long time of cohabitation). In the same way, microbiome would certainly
differ between different groups of people and would depend on factors like environment, weather,
food and even culture. Not to forget the difference between microbiomes in different animals. It is
a good scientific improvement, but the question is(based on above mentioned factors) what is the
use of such data? Will it be useful to cure diseases or are we complicating ourselves with
humongous amounts of useless information? Future scientific improvements might hopefully give
us the answer.
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LarryW
May 15, 2012, 4:14 PM
More than 50 years ago, I was learning in high school that the cow had multiple stomachs and its
digestive system made use of bacteria to digest. As even typical today, it never occurred to most
then, as now, that what was the case of the cow was also likely similar to us humans, being
animals, you see.
It was obvious to me then, so these details are not a surprise. It's a surprise that it took so long.
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How Bacteria in Our Bodies Protect Our Health - Scientific American
deometer
10/25/15, 1:40 PM
May 15, 2012, 5:27 PM
Most Popular
Antoine Béchamp discovered and promoted this fact well over 125 years ago (see "terrain theory"),
yet he was ridiculed and dismissed by the scientific community at large in favor of Louis Pasteur who insisted that a "healthy" human body was completely sterile. So Pasteur's inadequate
teachings became the ruling medical paradigm, and Béchamp's considerable body of research was
put aside and forgotten. If we had listened to Béchamp, we would have accepted that "the human
body is not such a neatly self-sufficient island after all" ages ago and our current progress and
understanding would be light years ahead.
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An Overreaction to Food
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deometer  deometer
May 15, 2012, 5:29 PM
Time Travel Simulation
Resolves “Grandfather
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That would be Antoine *Bechamp (apparently the commenting system doesn't display accented
letters)
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Christine Gorman  deometer
May 15, 2012, 6:02 PM
Back to the Future, Part II
Predicted Techno-Marvels
of October 21, 2015
Interesting point about Pasteur. I did not know that he thought the body was sterile.
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Stagnaro
It is evident that human life is in symbiosis with bacteria, as well as other environmental agents.
The point is how is it possible recognise at the bedside when life is encouraged, or not, by bacteria?
In my opinion, the absence of Acute Antibody Synthesis, I described in 1997, is a reliable clinical
tool among an awful number of others: Stagnaro-Neri M., Stagnaro S., Semeiotica Biofisica del
torace, della circolazione ematica e dell’anticorpopoiesi acuta e cronica. Acta Med. Medit. 13, 25,
1997
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May 16, 2012, 7:47 AM
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Beth Lambert
May 17, 2012, 1:29 PM
Why is there so much autism, ADHD, food allergies, asthma?? Changes to the human microbiome
(in combination with other environmental factors) is what is leading to an unprecedented number
of children developing autism, ADHD, food allergies, asthma and many more chronic conditions in
the industrialized world. Yes, imbalances in our microbial ecology are resulting in dysregulated
immune systems; What's more, commensal microorganisms are also responsible for helping us to
detoxify and eliminate environmental toxins as they enter our bodies (including heavy metals,
pesticides, and other chemicals). See Rowland et al., Archives of Environmental Health 39, no 6
(1984):401-8; there are volumes of articles published in the medical literature on this subject. We
are raising an entire generation of immunocompromised children because the human microbiome
(and thus immune function) has been been altered considerably over the last few decades in
America. To learn more, see A Compromised Generation: The Epidemic of Chronic Illness in
America's Children www.acompromisedgeneration.com or Epidemic Answers
www.epidemicanswers.org
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May 17, 2012, 11:19 PM
I have read that there are about 10+13 cells in the human body.
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If we were to assume there to be ca. 10 times as many bacterial cells in our constitution, that would
make ca. 10+14 bacterial cells
If the bacterial cells are about 1/10 the size, & therefore guesstimating to be about 1/10 the weight
of a human cell, then the weight of the bacterial cells would be ca. equal to the weight of the human
http://www.scientificamerican.com/article/ultimate-social-network-bacteria-protects-health/
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How Bacteria in Our Bodies Protect Our Health - Scientific American
10/25/15, 1:40 PM
cells.
Master's in Education
So a 150 lb person would be 75 lbs "human" and 75 lbs "bacteria".
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NCATE Accredited. Learn More Today!
It would be interesting to know how this number (10 times as many bacterial cells in a human )
was derived.
Any microbiologists reading this thread??
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robbinlynn
Latest from SA Blog Network
May 18, 2012, 7:34 PM
My doctoral thesis work in the 1990's involved host-commensal interactions, and we were
generally relegated to the backwaters of the microbiological meetings. It's nice to see that this
crucial area of interface biology is finally getting the attention it deserves.
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