Western diets that include significant amounts of the additive maltodextrin, a filler compound added to the sweeteners Splenda and Equal, may contribute to an increased susceptibility to Crohn’s disease, according to new research from the Cleveland Clinic Lerner Research Institute, OH. There is a clear link between bacteria and inflammatory bowel disease (IBD), with previous studies reporting differences in the types of bacteria and location of bacteria in the intestines of individuals with Crohn’s disease.
Investigators led by Christine McDonald, PhD, assistant staff, pathobiology department, Lerner Research Institute, looked at how bacteria were altered by components of the Western diet to better understand how diet affects bacteria associated with IBD, an area of research not well understood. They reviewed how certain components of this diet alter E. coli bacteria to increase their ability to form biofilms and adhere to intestinal epithelial cells — features associated with the disease.
The investigators grew E. coli bacteria isolated from a Crohn’s disease patient in the lab with different substances found in a Western diet and tested their ability to form biofilm structures similar to those found in the gut of Crohn’s disease patients. Initially, they compared bacteria that were fed glucose (the simplest form of sugar) to bacteria that were fed artificial sweeteners. Surprisingly, Dr. McDonald’s group found that the sweeteners alone didn’t have an effect, but maltodextrin dramatically changed the bacteria.
When the researchers looked at how well the bacteria adhered to plastic or live intestinal cells, they found that bacteria grown in maltodextrin were stickier, resulting in thicker biofilms, and a greater number of bacteria piled up on the surface of intestinal cells. This finding is significant since maltodextrin is in a wide variety of products ranging from sweeteners and processed foods to medications and other products. Dr. McDonald cautioned that it is too early to conclude that maltodextrin promotes disease, though their results suggest that maltodextrin can cause E. coli to gain features associated with disease and therefore, potentially, increases an individual’s overall risk of developing IBD. Studies are planned to test this more directly in experimental mouse models of IBD. “While dietary additives like maltodextrin are generally considered safe, these findings suggest that perhaps people who are prone to develop IBD should consider limiting their maltodextrin intake,” Dr. McDonald said.
Previous research suggests that consumption of a Western diet — one that is high in fat, low in fiber and rich in processed foods — is associated with the development of Crohn’s disease. Other studies have observed striking differences between the bacteria found in healthy intestines and those affected by Crohn’s disease. In a healthy gut, the normal bacterial community is separated from direct contact with the intestinal cells, while in Crohn’s disease patients, gut bacteria form a dense structure (a biofilm) in close contact with the cells. Additionally, some studies have shown an increase in the amounts of E. coli and demonstrated that Crohn’s disease-associated E. coli has special features, making the strain more adhesive and invasive.
This study received no pharmaceutical funding. It was supported by the National Institutes of Health (R01DK082437) and the Howard Hughes Medical Institute “Med into Grad” Initiative.
Dr. McDonald will present these data on Tuesday, May 22 at noon PT in Halls C-G of the San Diego Convention Center.