Research zeroes in on effects of common food additive

Everyone's heard a lot about questionable food additives lately, but a recent study provides new insight on why emulsifiers are something to avoid.

Commonly found in packaged and processed foods, emulsifiers add texture and extend shelf life but according to the US-based research team, they could alter your composition of friendly gut bacteria -- or gut microbiota -- and lead to inflammation.

"Food interacts intimately with the microbiota so we considered what modern additions to the food supply might possibly make gut bacteria more pro-inflammatory," says co-author Dr. Benoit Chassaing of the Institute for Biomedical Sciences at Georgia State University.

Among the undesirable, long-term side effects besides intestinal inflammation are inflammatory bowel disease (IBD) and metabolic syndrome, according to the study, which was published in the journal Nature.

Metabolic syndrome is a collective term for several disorders commonly related to obesity that can progress to type 2 diabetes, cardiovascular disease and liver problems.

Incidence of IBD and metabolic syndrome has been on the rise since the 1950s, say the researchers.

"The dramatic increase in these diseases has occurred despite consistent human genetics, suggesting a pivotal role for an environmental factor," says Dr. Chassaing.

IBD and metabolic syndrome are also characterized by an imbalance in the composition of friendly gut bacteria -- a population that tops 100 trillion in the intestinal tract of a healthy individual, according to the study.

"A key feature of these modern plagues is alteration of the gut microbiota in a manner that promotes inflammation," says co-author Andrew Gewirtz, also of the Institute for Biomedical Sciences at GSU.

In the experiment, two mice were fed the emulsifiers polysorbate 80 and carboxymethylcellulsose in proportions equivalent to regular human consumption, which is significant since they are used in nearly all processed foods.

Sure enough, after a dousing with emulsifier, entire colonies of the mice's gut bacteria were banished from their habitat in the mucus layer of the gut, migrating to the epithelium and creating a pro-inflammatory environment.

The team is currently testing additional emulsifiers on humans.