Inside our guts is a diverse ecosystem of bacteria:the microbiome.
But the makeup of the community can depend on what we eat.
Emulsifiers are food additives that extend the shelf life of processed foods.
And now research with mice finds that consuming emulsifiers may throw off the microbiome's delicate balance and thereby contribute to obesity and inflammatory bowel disease.
In the study, mice were fed doses of common emulsifiers in their water and mouse chow.
The substances appeared to make it easier for gut bacteria to chew through the layers of mucus that typically line the intestine.
The result was the triggering of chronic colitis in mice with impaired immune systems that predispose them to the condition.
And even in mice with normal immune systems, emulsifier consumption appeared to trigger mild intestinal inflammation.
These mice then tended to overeat and become obese and insulin resistant.
The study is in the journal Nature.
Could emulsifiers cause the same health consequences in humans and be behind some of the obesity trend?
The researchers hope to find out in future studies.
If nothing else, they write that their new finding suggests that there should be improved testing on the total health effects of chemicals in our food.