Food additive: E415 would be able to modify our intestinal microbiota

During their manufacture, so-called processed foods are often processed by various food additives which are there to modify their texture, enhance their aromas or to improve their shelf life. Among them is xanthan gum, or E415, pointed out in a scientific study

Accused of affecting the gut microbiota

Marketed since the 1960s, xanthan gum is used in salad dressings, ready meals, meats and many other products, to thicken foods from the food industry. Until now considered harmless, it has just been implicated by researchers in the modification of the intestinal microbiota.

The additive E415 is produced by the fermentation of sugar using the bacterium Xanthomonas campestris. This process then creates a gelatinous liquid which, once dried and turned into a powder, will be added to food.

An additive digested by the bacteria of the microbiota

As said before, xanthan gum was considered harmless due to the inability of gut bacteria to digest it. But the authors of this study have just called this assertion into question by demonstrating that bacteria are now able to degrade this additive made up of several sugars.

Two targeted bacteria

This work, which was led by two researchers from the University of Michigan in the United States, was published in the journal naturemicrobiology. They targeted two bacteria capable of destroying xanthan gum, by working on mouse models and by bioinformatics analyses. The first bacterium belongs to the Ruminococcaceae family and the second bacterium is Bacteroides intestinalis. Both are capable of reducing the E415 molecule in the intestine.

“The bacterium that can digest xanthan gum has been isolated from the gut microbiota of a surprisingly large number of people in industrialized countries.”, explains Sabina Leanti La Rosa, one of the researchers who participated in the project. “We were surprised at how well human gut bacteria have adapted to this additive since it was introduced into the modern diet only fifty years ago.“, she added.

Higher caloric intake

Through this research, scientists have also revealed the fate of xanthan gum, once “digested” by bacteria. Xanthan gum then becomes constituent monosaccharides, which are then fermented to produce short chain fatty acids that can be assimilated by the human body. But, points out Sabina Leanti La Rosa, “these fatty acids are known to provide up to 10% of calories for humans”. Xanthan gum would therefore also be responsible for a greater caloric intake, once digested.

What consequences on health?

For the scientist,based on this study, we cannot conclude if and how xanthan gum affects our health. But we can say that this additive affects the gut microbiota of people who ingest it through food.”.

As a reminder, xanthan gum was reassessed in 2017 by the European Food Safety Authority (EFSA), the European food safety authority, which concluded that it was not dangerous, although it could have laxative effects. Further complementary studies are therefore necessary. For Sabian Leanti LaRosa, “authorities should perhaps take this new knowledge into consideration when evaluating commonly used food additives”.

Slide: Food Additives Guide