Common additives in ice cream, margarine, packaged bread, and many processed foods may promote the inflammatory bowel diseases ulcerative colitis and Crohn's disease, as well as a group of obesity-related conditions, say scientists.

In mouse experiments, researchers found emulsifiers — chemicals added to many food products to improve texture and extend shelf life — can change the species composition of gut bacteria and induce intestinal inflammation. Such inflammation is associated with the frequently debilitating Crohn's disease and ulcerative colitis, as well as metabolic syndrome, a group of conditions that increase risk for Type 2 diabetes, heart disease, and stroke.

Consuming emulsifiers increased the risk of colitis, mimicking human inflammatory bowel disease, in mice genetically susceptible to the condition, the study found.

Georgia State University microbiologist Benoit Chassaing, whose study appears in the journal Nature, said the effects seen in mice “may be observed in humans as well.”

Incidence of inflammatory bowel disease and metabolic syndrome started rising in the mid-20th century, roughly the same time food manufacturers began widespread emulsifier use.

“We were thinking there was some non-genetic factor out there . . . that would be explaining the increase in these chronic inflammatory diseases,” Georgia State immunologist Andrew Gewirtz said. “And we thought that emulsifiers were a good candidate because they are so ubiquitous and their use has roughly paralleled the increase in these diseases. But I guess we were surprised at how strong the effects were.”