Our gut bacteria could be at risk due to a common food additive.
Our gut bacteria could be at risk due to a common food additive.

Common food additive may be ‘harmful’ for health

A common food additive found in more than 900 products including chewing gum and mayonnaise could be doing significant damage to people's gut health and even cause serious diseases such as cancer.

An alarming University of Sydney study has found the food additive "E171" - commonly used in high quantities in foods and some medicines as a whitening agent - may have a "substantial and harmful" influence on human health.

The colourant is composed of titanium dioxide nanoparticles which are widely used in the food industry.

In France, health experts are so concerned about the effects of E171 that the government is banning its use from next year.

The university mice study found the consumption of food containing E171 has an impact on the "gut microbiota" - the trillions of bacteria that inhabit the gut - which could trigger inflammatory bowel diseases and bowel cancer.

Nanotoxicology expert Wojciech Chrzanowski from the university's school of pharmacy said while it was known that dietary composition impacts health, "the role of food additives is poorly understood".

"There is increasing evidence that continuous exposure to nanoparticles has an impact on gut microbiota composition … since gut microbiota is a gate keeper of our health, any changes to its function have an influence on overall health," Dr Chrzanowski said.

Health researchers say dementia, auto-immune diseases, cancer metastasis, eczema, asthma and autism are among a growing list of diseases that have been linked to soaring exposure to nanoparticles.

Associate Professor Laurence Macia said the consumption of E171 should be better regulated.

"Our research showed that titanium dioxide interacts with bacteria in the gut and impairs some of their functions which may result in the development of diseases," she said. "This study … found that titanium dioxide did not change the composition of gut microbiota, but instead it altered bacteria activity and promoted their growth in a form of undesired biofilm."

Biofilms are bacteria that stick together and have been reported in diseases such as colorectal cancer.