Researcher Links Digestive Problems to Food Additive

Christine McDonald, PhD

It’s estimated that more than 1.4 million Americans have some form of inflammatory bowel disease (IBD). That number has dramatically increased over the past 50 years, and scientists now think they know why.

“It’s happened too quickly for it to be a genetic change,” says Christine McDonald, PhD, a researcher in Cleveland Clinic’s Department of Pathobiology at the Lerner Research Institute. “This points to something in our modern lifestyle that is promoting disease development.”

Reviewing the results of studies done in livestock to determine the effect of different dietary components on animal health, Dr. McDonald and her team zeroed in on one additive in particular: maltodextrin.

Maltodextrin is a starch-derived food additive that is commonly used as a thickening, coating or filling agent. It’s found in thousands of food items including sports drinks, artificial sweeteners, potato chips, salad dressing and beer.

Is the Western Diet to Blame?

Beginning in the 1950s, Americans increasingly began eating processed, pre-packaged foods high in fat and carbohydrates and low in dietary fiber – now known as the Western diet. Food additives serve to lengthen shelf life, make food look and smell more attractive, and improve flavor and texture.

Dr. McDonald says that food additives generally are considered safe and are not tracked in dietary studies. “So it’s hard to know how much and which food additives we’re really consuming,” she says.

Through her research, Dr. McDonald discovered that maltodextrin alters intestinal bacteria to make them “stickier,” which may present challenges to a normal digestive process, let alone someone with IBD.

In people with IBD, the bacteria in the gut sticks more to the surface of the epithelium – the layers of cells that line the intestines. In healthy people, the bacteria is prevented from sticking to the epithelium because the cells make a layer of mucous, a thick gel-like substance. People with IBD have a much thinner mucous layer or are missing it altogether.

In another recent study, her lab found that maltodextrin promotes survival of salmonella, a bacterium commonly associated with food poisoning. Her research also indicates that maltodextrin can increase the amount of bacteria on the surface of the gut epithelium, as well as decrease antibacterial defenses, creating the ideal environment for developing Crohn’s disease.

Mom Was Right

The saying, “You are what you eat” is true. “What you eat can have a dramatic effect on your health,” Dr. McDonald says. “A balanced diet and fresh food are important. But that doesn’t mean you can’t eat potato chips every now and then.”

Other factors that may contribute to IBD include over-the-counter NSAIDs, alcohol and stress. Smoking also affects digestive health, altering the microbiota in the gut and epithelium. Surprisingly, some environmental exposures, such as pets and household dust, actually can help train the body’s immune system to differentiate normal from abnormal bacteria and decrease IBD risk.

So what’s next? Researchers in Dr. McDonald’s lab now are investigating how environmental factors combine with genetics to affect the body’s immune response.

“We’re working on detailed molecular studies and pre-clinical models,” Dr. McDonald says, adding that they have applied to the National Institutes of Health for a grant to fund the studies. “We hope to soon begin exploratory studies with patients using diet as an adjunctive therapy to determine if removing food additives will be helpful to patients at risk for IBD.”


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