Surge in obesity and diabetes could be linked to food additives

https://www.newscientist.com/article/2076906-surge-in-obesity-and-diabetes-could-be-linked-to-food-additives/

9 February 2016

Studies on a simulated human gut have added further evidence that emulsifiers, found in most processed foods, might be linked to obesity, diabetes and inflammatory bowel disorders.

Emulsifiers are used to improve a food’s texture and to prevent mixtures from separating, particularly in ice cream. Last year, Benoit Chassaing of Georgia State University showed that mice that drank water containing one of two emulsifiers underwent changes in gut bacteria and inflammation of the gut – changes that led to obesity and diabetes in these animals.

However, mice that didn’t have any gut bacteria because they had been raised in a sterile environment didn’t become ill when given the same additives, suggesting that it is the emulsifiers’ effect on the microbiome that is to blame. When the ill mice stopped consuming emulsifiers, their gut bacteria gradually returned to normal.

Now Chassaing has supported his findings in mice using a simulation of the human gut. Working with a team in Belgium, he looked at two emulsifiers: carboxymethylcellulose (E566 on EU labels) and polysorbate-80 (E433). When added to a series of flasks that mimic the conditions of the human digestive tract, each caused an increase in the levels of a bacterial protein called flagellin, known to cause inflammation at high concentrations.

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The simulator results are more convincing than the mouse studies, since lab animals and humans have vastly different gut microbiomes, says Glenn Gibson of the University of Reading in the UK, who studies gut disorders. “The definitive test, however, is obviously a human trial.”

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