Fighting E. coli the Old-fashioned Way
By Jeff D. Leach
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 strains of E. coli 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 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.
Modern Diet Has Fiber-Poor Grains
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 plow to plate--not to mention that the bad bugs have us outnumbered.
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.
Public Hesitates to Eat Produce
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 the National Cancer Society is 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.
Jeff D. Leach is the Director of the Paleobiotics Lab