Food Additives Affect Gut Bacteria

Research indicates that certain emulsifiers — used in many processed foods — promote colitis, obesity, and metabolic syndrome in mice.


A new study conducted at Georgia State University has shown that certain emulsifiers used in processed foods can promote colitis, obesity, and metabolic syndrome in mice. The study, published in the journal Nature (March 2015), suggests that these widely used food additives may also affect human health, and in particular the human microbiome, which is an important factor in many chronic diseases.

“Food interacts intimately with the microbiota, so we considered what modern additions to the food supply might possibly make gut bacteria more pro-inflammatory,” explains study coauthor Benoit Chassaing, PhD, of the Institute for Biomedical Sciences at Georgia State. Over a period of 12 weeks, the team fed mice two commonly used emulsifiers — polysorbate 80 and carboxymethylcellulose — at doses comparable with what’s in many processed foods. They observed that emulsifier consumption altered the gut microbiome composition to a point that caused inflammation.

The changes in gut bacteria triggered chronic colitis in mice that were genetically prone to the disorder due to abnormal immune systems.

In mice with normal immune systems, emulsifiers triggered mild intestinal inflammation and metabolic syndrome, characterized by increased food consumption, obesity, hyperglycemia, and insulin resistance.

The researchers are now testing other emulsifiers in mice studies and designing experiments to investigate emulsifiers’ effects on humans.

Illustration by Dan Simple

Heidi Wachter is the staff writer for Experience Life.

Illustration by Dan Sipple

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