What’s the best defense against another outbreak of food-borne pathogens? While politicians, scientists and farmers strive to come up with new technological solutions — ranging from electromagnetic processing to radio frequency identification tags — a simpler, far healthier solution is close at hand.
The simple defense is stocked in the produce aisle of your local supermarket: Good old dietary fiber, found in a myriad of healthy fruit and vegetables.
Hold on, you ask, isn’t produce part of the problem? Not necessarily in the way you think.It’s the lack of vegetables in our diets that starves the healthy bacteria in our guts.In other words we’re not feeding our intestinal defense team the fiber they need to fight the bad bacteria.
So, what makes up our intestinal defense team? As you read this, there are trillions of tiny microbes (including billions of harmless strains of E.coli) living throughout your continuous gastrointestinal tract.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 soldiers, 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 plow to plate -– not to mention that the bad bugs have us out numbered.
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 debate about 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 irony is that the rash of media coverage of recent outbreaks of food-borne viruses may have made the problem worse by paving the way for an additional decrease of fiber in the American diet, resulting in poorer gut health and reduced ability to resist infectious agents.
However, the crisis also provides an opportunity for industry and the government to highlight the importance of increasing fiber intake via fruits and vegetables.
To resist E.coli 0157:H7 specifically, our diet needs to support the growth of a group of healthy bacteria in the human gut known as bifidobacterium.We can fortify our natural resistance by increasing our intake of dietary fibers known as oligosaccharides -– found in plants such as bananas, onions, leeks, garlic, chicory, and artichokes.
Bifidobacteria exert powerful effects against pathogens through competition for colonization sites and nutrients in the gut, acid excretion, production of antimicrobial peptides and overall reduction in colonic pH.If properly fed and stimulated, these good 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 why 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.
Jeff Leach is a science writer, anthropologist, and health advocate.He is the co-founder of the newly formed and developing International Fiber Council.
Jeff was recently tapped by the World Health Organization to further develop his theory for reducing human exposure to food-borne pathogens in the global population by reintroducing certain dietary fiber sources in human diet.
Published May 1, 2007