Dietary Emulsifier Consumption Promotes Colon Cancer Development

A commonly-used food additive has been linked to intestinal inflammation and colon cancer in mice.

Emulsifiers are often added to a majority of processed foods to aid texture and extend shelf life. However, findings from a new study published in Cancer Research indicated that the regular consumption of dietary emulsifiers exacerbated tumor development in mice.

“The incidence of colorectal cancer has been markedly increasing since the mid-20^th century,” said lead researcher Emilie Viennois. “A key feature of this disease is the presence of an altered intestinal microbiota that creates a favorable niche for tumorigenesis.”

The authors noted that the findings suggest dietary emulsifiers are partially responsible for inflammatory bowel disease promoting colon tumorigenesis.

“The dramatic increase in these diseases has occurred amidst constant human genetics, suggesting a pivotal role for an environmental factor,” said researcher Benoit Chassaing.

Since prior research suggests low-grade inflammation in the intestine is promoted by the consumption of dietary emulsifiers, the researchers hypothesized in the current study that emulsifiers may affect the gut microbiota in such a way that it leads to the promotion of colorectal cancer.

For the study, researchers fed mice with 2 commonly used emulsifiers: polysorbate 80 and carboxymethylcellulose. The administered dose modeled the broad consumption of the numerous emulsifiers found in most processed foods.

The results of the study showed the emulsifiers drastically changed the composition of gut microbiota in mice by making it pro-inflammatory, and creating a niche that favored cancer induction and development. Furthermore, changes in bacterial species caused the bacteria to express more flagellin and lipopolysaccharide.

While using a model of colorectal cancer, the researchers found that consumption of dietary emulsifier was enough to make the rodents more susceptible to the development of colonic tumors, because it created a pro-inflammatory environment associated with an altered proliferation/apoptosis balance.

The findings demonstrated that emulsifier-induced alterations in the microbiome were sufficient enough to drive alterations in intestinal epithelial cell homeostasis. The effects of the emulsifiers were found to be eliminated in mice without microbiota.

Furthermore, transplanting microbiota from emulsifier-treated mice to germ-free mice transferred alterations in intestinal epithelial cell homeostasis.

The authors noted that this suggests a central role played by the microbiota in tumor development. Furthermore, the findings support that agitating the host-microbiota interactions, causing low-grade gut inflammation, can promote colon carcinogenesis, according to the study.

The researchers next plan to investigate which microbiota members are triggering the detrimental effect to identify the mechanism of altered microbiota-induced cancer promotion.