Feedback is incredibly important. No one
can hope to get better at anything without some way to measure how they’re
doing. I’m a great believer in feedback; I regularly contribute to Trip Advisor
and hang around in shops to speak to managers about how great a job one of
their employees did at serving me (much to my boyfriend’s embarrassment). So,
when I read an article (http://well.blogs.nytimes.com/2013/04/12/where-germs-hide-in-your-kitchen/?hpw)
about the Bacteria in your kitchen in the NY Times blog recently, the need for
feedback kicked in.
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| Image provided by sjfranks (www.morguefile.com/creative/sjfranks) |
It’s a piece by Anahad O’Connor, about a
study conducted by NSF International. This study investigated different parts
of the kitchen to identify potentially dangerous Bacteria lurking in the heart
of every home.
Now, don’t misinterpret me. I’m not saying
that the post made me angry, or even livid to the point of scarlet, incendiary
rage. I’m not saying that I shrieked in horrified rage across the quiet mutter
of conversation at my local pub last Friday evening when I read the article.
I’m not saying that at all. In fact, there are some brilliant aspects to this
piece, which I’ll mention as we go on. However, there are also a couple of
areas that I’d have written very differently. Be clear, this isn’t meant to be
a criticism of the article, or of its creator (an immeasurably better science
writer than me – I’ve never written a book!). This isn’t smack talk, or beef. I’m trying to open up the topic of
environmentally and clinically important Bacteria from my own personal
perspective, hopefully to create a little scientific debate. This article is a
springboard to talk about issues, which I think, many writers and journalists
are getting wrong when it comes to microbes.
O’Connor should be congratulated for
bringing the issue of microbes in the kitchen to the public’s attention. For
someone who runs home to tell my family and friends about the millions of
Bacteria we encounter on a daily basis, it’s exciting when these
underrepresented but crucial little critters get a big stage appearance. I’m
saddened though, that there’s no mention of the obvious limitations to the
study. Looking for potentially dangerous Bacteria isn’t like looking for life
on other planets. Take a deep breath – there you found some potentially
dangerous microbes, and now they’re in your lungs. I’m typing this on a
keyboard – eurghhh that means I’m touching potentially dangerous Bacteria! You
see what I’m getting at. If you set out to find food-borne Bacteria in a place
where food is prepared, stored and eaten, you’ll definitely find what you’re
looking for.
On a more important note, is it healthy to
spread the perception that ‘nasty germs’ live in the kitchen? Should we be cracking open the bleach every
morning before we prepare breakfast?
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| Image provided by pegesus (www.morguefile.com/creative/pegesus) |
The Hygiene Hypothesis is the idea that as
standards of living have risen since the industrial revolution, so standards of
cleanliness in the home have improved, which has, in turn, lead to a dramatic
increase in immune disorders such as hay fever and asthma. This hypothesis has
been around for as long as I have and in that time, researchers have made huge
leaps towards understanding the effects of a more ‘clean’ domestic environment
on human health. The bottom line is: a diverse and healthy population of
microbes in the body, from birth to death, is how our immune system keeps
itself in check. Scientists are now starting to realize that we humans are
‘superorganisms’ because we are made up of more than just human cells.
Bacterial cells outnumber human cells in our bodies, and not just by a slim
margin, by ten to one. So for every skin cell, brain cell or blood cell, in
your body, there are ten times more Bacteria. These microbes are much smaller
than our own cells, but they’re as much a part of you as your own cells. These
microbes make up what’s called the human ‘microbiome’.
One thing that many people don’t realize,
is that by having a complete layer of Bacteria on every surface of your body,
you’ve got a ready made, primary defense mechanism against other microbes.
Colonisation of the gut by Bacteria is almost impossible if the existing
population is healthy, even if the would-be colonizers are usually found in the
gut; treat your microbiome well, and it will fiercely defend you and kill off
foreign attackers - even if those attackers are harmless and would love to live
in your gut. The chance of being colonized by an individual bacterial cell that
happens to have grown on your blender is slim. To be fair, we’re constantly
being bombarded with Bacteria, and sooner or later at least one will make it
past the bacterial doorkeepers and the immune system, so I’m not encouraging
anyone to live in a house of squalor. A common sense approach to cleanliness is
key. Besides, who didn’t realize that
the vegetable draw and the water dispenser would be full of Bacteria and mould??
Another aspect of this article that I found
disappointing, was the heavy talk about E.
coli and Salmonella; every
journalist’s ‘go-to’ nasties when it comes to food poisoning. Did you know,
however, that the most common cause of bacterial gastroenteritis (food
poisoning) is a bacterium called Campylobacter
jejuni? Few people have heard of the Campylobacter
family, but they cause more infections of the digestive system, worldwide, than
E. coli and all the Salmonella species combined!! Campylobacter causes acute infection of
the digestive tract (with all the horrifying symptoms you’d expect), and can
result in a paralysis disorder called Guillain Barré Syndrome. Infection with C.
jejuni is nasty, and every year up to 2 million Americans are left pinned
to the bathroom floor, unsure of which end they should point towards the bowl,
by it. This number isn’t dropping either. I’m not trying to scare you about
food poisoning, instead I’m trying to highlight the fact that lazy journalists
go back to E. coli and Salmonella time and time again,
perpetuating the idea that these Bacteria are the ones we should be worried about.
The only reason journalists got to hear of them in the first place is because
there have been a handful of highly publicized outbreaks of dangerous versions
of these species – while C. jejuni
infects people at a fairly constant rate, so that doesn’t count as news for
some reason. C. jejuni isn’t mentioned in the NSF report either, and that’s
because it’s a microaerophile, meaning
it can only grow in a low oxygen environment and dies quickly when exposed to
normal, atmospheric levels of oxygen. It is found naturally in the guts of
chickens, so is commonly found in chicken meat. This isn’t a problem, as long
as you cook your poultry produce properly because the cooking process kills the
Bacteria.
Infectious Bacteria are like people – the
vast majority will never bother you or have any direct impact on your life at
all; the ones you do encounter will mostly be nice; but very occasionally
you’ll come across a rotter. Poor old E.
coli, and it’s cousins the Salmonella
species are generally decent, upstanding Bacteria, harmlessly going about their
business without any damage to us humans, but they get hounded! The truth is,
your body is made up of more E. coli
cells than human cells, and every gram of solid waste (poo) you produce
contains 1000000000000 E. coli
cells!!! Every single person’s intestines are crammed full of E. coli, which is great because those
tiny cells help to digest our food, and are also producing up to 70% of the
vitamin K we absorb. If we tried to avoid E.
coli, we wouldn’t get very far. Of course sometimes a stray E. coli cell wanders off to the urinary
tract, or develops toxins which cause disease, but those are the evil
psychopaths of the microbial world, not the Average Joes.
On a side note, biologists use a binomial
nomenclature for naming all organisms scientifically and this system comes with
a couple of rules. The first part of a scientific name is always the genus; it
starts with a capital letter and can be abbreviated to just the first letter.
The second part is the species name, which is always in lowercase letters.
Since they’re both in Latin, they have to be italicized. So, for Anahad
O’Connor’s benefit, E. coli was
almost right, but you didn’t put it in italics, and Salmonella needed a capital S and italics, because it’s the genus
and not the species name. I’m sure a physicist would cringe if I were to write
Einstein’s famous equation as E=MC2, right?
For more information about the different
roles Bacteria play in our body, a good place to start is the excellent review
paper by Stig Bengmark called ‘Gut microbiota, immune development and function’
(Pharmacological Research Volume 69, Issue 1, March 2013, Pages 87–113).
