OPINION
Fighting E. coli the old-fashioned way
by
Jeff D Leach
Paleobiotics Lab
 In
the wake of E. coli 0157:H7 outbreaks associated with spinach and other
produce in 2006, the new 110th Congress will be dusting off and
reintroducing the Food Safety Act (S. 729), initially proposed in 2005 by
Senator Dick Durbin (D-IL), to assure the American public that the
government is working hard to substantially reduce future food-borne
outbreaks.
Unfortunately, this well-intended
legislation will fall short of anything meaningful, as its patrons most
certainly fail to understand the basic evolutionary rules of the germ
warfare raging in the American gut and the bigger challenges facing the
populace in this biological arms race.
As executives of
the produce industry hit hardest by the illness and deaths attributed to
E. coli 0157:H7 in 2006 brace for a possible onslaught of new
regulations and additional inspectors trudging about their fields and
packaging plants, they need only look out to the fields beyond their
office windows to see a better solution to what ails them and the American
public.
Among the lush
greens, yellows and reds of the American produce landscape, lies a simple,
but critical component, to our evolutionary success as a species and the
best defense we have ever had – or will likely ever have – against
reducing our risk from
E. coli 0157:H7 and the assortment of pathogens that seek
to do us harm on the biological battle field that is us.
The simple defense to be found amid these
fields is good old dietary fiber.
As you read this,
there are trillions of tiny microbes (including billions of harmless
strains of E. coli) living throughout your continuous gastrointestinal
tract – from mouth to anus. These tiny evolutionary hitchhikers have been
with you every minute of every day from the moment you entered this world
and will be so until you die. And then they will eat you. But that’s the
good news.
The bad news is
our so-called modern diet of highly processed fiber poor grains, in
addition to added sugars and fats, is literally starving our “friendly”
bacteria and putting us at increased risk. The friendly bacteria in our
bodies are the first line of defense against invading pathogens, such as
E. coli 0157:H7. Like any good soldier they require nutrients to fight the good
fight and dietary fiber is an important part of that nutrient base.
Simply stated: Fiber is not food for us,
it’s food for bacteria that live in our gut.
Our not-so-distant ancestors regularly
consumed between and often more than 50 and 100 grams of dietary fiber
from diverse sources every day. This is the nutritional reality
upon which our modern genome was selected and the symbiotic relationship
which the trillions of bacteria in our gut evolved to depend upon.
However, the
average American today consumes about 12 to 15 grams a day – roughly half
of what the government recommends and only a fraction of what our gut bugs
need in order to resist infection and disease caused by a steady stream of
pathogenic bacteria and viruses that enter our gut every day.
No amount of government oversight will ever
completely remove the threat of pathogens in our food supply. There are
too many variables from plough to plate – not to mention that the bad bugs
have us out numbered.
While a cleaner
and safer food supply has allowed our species to maintain mammalian
dominance, we must not lose sight of the delicate nutritional requirements
of our friendly gut bugs and the indispensable role they play in our
tenuous existence on this microbe-dominated planet.
The health
implications of our staggering drop in consumption of dietary fiber has
opened the door to E. coli 0157:H7
and its band of pathogenic
brothers who make millions of people sick every year, sending hundreds of
thousands to the emergency room with diarrhea, bloody diarrhea, intestinal
cramping, and fever, and sending an increasing number of us, to the
morgue.
The
important symbiotic relationship we share with our friendly microbes and
their role in our natural resistance to infection should be taking center
stage in the upcoming Congressional hearings on how to best protect “the
people” from the inevitable food-borne pathogens associated with produce,
and specifically, how to deal with this monster
E. coli 0157:H7.
The recent outbreaks have understandably
made the American public skittish not only about spinach and other produce
tainted with E. coli 0157:H7, but about produce in general. This may pave
the way for an additional decrease of fiber in the American diet,
resulting in poorer gut health and reduced ability to resist infectious
agents.
The media attention given to E. coli 0157:H7
in 2006 has once again raised the awareness of deadly pathogens in our
environment. This may be an opportunity, though tragic in its realization,
for industry and the government to highlight the importance of increasing
fiber intake via fruits and vegetables. Current government health messages
to do so have had little success. Maybe it’s time to change the message.
For E. coli 0157:H7 specifically,
stimulating the growth of a group of healthy bacteria in the human gut
known as bifidobacterium by consuming special prebiotic dietary fibers
known as oligosaccharides – found in plants such as onions, leeks, garlic,
chicory, and artichokes – can fortify our natural resistance.
Bifidobacteria
exert powerful effects against pathogens through competition for
colonization sites and nutrients in the gut, acid excretion and
antimicrobial peptides. If properly fed and stimulated, these bacteria
will do their evolutionary job and make life a living hell for invading
pathogens.
Interestingly,
bifidobacterium dominate the gut of breast fed babies, but are known to
decrease significantly as people get older. This may explain that even
though a number of age groups were sickened during the 2006 outbreaks, two
out of three of the deaths were elderly women. The third was a 2 year old
boy. A similar pattern was seen in a deadly outbreak in Scotland in 1986
that affected hundreds and killed 20. All deaths were among the elderly.
At a time when
researchers are finally acknowledging that nearly 20% of all
cancers are caused by infection – up from zero just a few decades ago –
and with hints that infection may play a causal role in such big time
killers as breast cancer and atherosclerosis, it may be time to start
asking who or what opened the pathogens door.
Ignorance of
evolutionary biology and the nutritional landscape upon which humans and
our microbes evolved should not preclude lawmakers and industry from
exploring the role of dietary fiber in reducing our casualties in this
evolutionary arms race. Continuing to ignore this simple and
easy-to-implement strategy will only result in further human suffering.
I, for one, will
be having a salad tonight.
*Comments about this article would be most welcome (E-mail).
Further Reading
Mixed culture
fermentation studies on the effects of synbiotics on the human intestinal
pathogens Campylobacter jejuni and Escherichia coli.
Anaerobe. 2003
Oct;9(5):231-42.
Pathogen survival in
the external environment and the evolution of virulence.
Biol Rev Camb Philos Soc. 2004 Nov;79(4):849-69. Review.
Evolutionary
perspective on dietary intake of fibre and colorectal cancer.
Eur J
Clin Nutr. 2007 Jan;61(1):140-2.
Shiga toxin of
enterohemorrhagic Escherichia coli type O157:H7 promotes intestinal
colonization.
Proc Natl Acad Sci U S A. 2006 Jun 20;103(25):9667-72.
Carbohydrate
preference, acid tolerance and bile tolerance in five strains of
Bifidobacterium.
J Appl Microbiol.
2006 Apr;100(4):846-53.
Cochran, Gregory M.
"Infectious Causation of Disease: An Evolutionary Perspective"
Perspectives in Biology and Medicine - Volume 43, Number 3, Spring 2000,
pp. 406-448
Evolutionary health
promotion. Prev
Med. 2002 Feb;34(2):109-18. Review.
Human Evolution, Nutritional
Ecology and Prebiotics in Ancient
Diet. Bioscience & Microflora Vol. 25, No. 1. pp 1-8
"Children on the
frontline against E. coli": typical hemolytic-uremic syndrome.
Clin Lab Sci. 2005 Spring;18(2):90-9.
Prevalence and risk
factors of genital Chlamydia trachomatis infection.
Medicina (Kaunas).
2006;42(11):885-94. Review.
Introducing inulin-type
fructans.
Br J Nutr. 2005
Apr;93 Suppl 1:S13-25. Review.
Non-toxic potentiation
of cancer radiotherapy by dietary oligofructose or inulin.
Anticancer Res.
2002 Nov-Dec;22(6A):3319-23.
Inulin/oligofructose
and anticancer therapy.
Br J Nutr. 2002
May;87 Suppl 2:S283-6. Review.
The association of
Helicobacter pylori infection with the development of gastroesophageal
reflux disease (GERD).
J
Egypt Public Health Assoc. 2001;76(3-4):265-79.
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