Sensitive to E466? Your microbiota plays a role
When it comes to additives, some people are more sensitive than others. Work by researchers from the Institut Pasteur on the additive E466, a very common emulsifier added to certain foods, shows that our individual sensitivity depends on our gut microbiota.
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Emulsifiers, texturizers, preservatives, colorants: (sidenote: Food additives Food additives are substances primarily added to processed foods, or other foods produced on an industrial scale, for technical purposes, e.g. to improve safety, increase the amount of time a food can be stored, or modify sensory properties of food. Source: World Health Organization ) which are very common in ultra-processed products, have invaded our cupboards. These include E466, or (sidenote: Sodium carboxymethyl cellulose Sodium carboxymethyl cellulose (or cellulose gum, E466) is a food additive with multiple functional properties: firming agent, coating agent, bulking agent, emulsifier, thickener, gelling agent, humectant, stabilizer, etc. Its use is authorized in a wide range of products from dairy products (creams, fresh or processed cheese, dairy desserts, etc.) to cooked fish, from ice creams to dried or canned vegetables, from confectionery to breakfast cereals, from certain meats or fish to mustards and soups, from appetizers to beer or certain spirits, and so on. Source: Food and Agriculture Organization of the United Nations ) , which is used in industrial ice creams and buns. The problem: several studies have alerted us to its potentially harmful effect on our intestinal and metabolic health.
A recent study 1 also points out that the composition of our microbiota could be altered by repeated consumption of this type of emulsifier. In a clinical trial previously carried out on healthy volunteers (7 consuming E466, and 9 controls not consuming it, for comparison), researchers had shown that people’s responses to this additive differ: some people are sensitive, and their gut microbiota is disrupted, while others are resistant and their flora remains unaffected.
This difference is explained by the microbial composition in our gut, according to the latest studies by the same researchers. In other words, your flora predicts whether you're one of the lucky ones who digest fluffy industrial buns without a care in the world or one of those people who react badly to E466!
Do food additives have an impact on behavior?
The gut microbiota predicts... and transmits!
To understand these differences, the researchers used a mini laboratory reactor capable of mimicking the human microbiota and testing the effect of E466 on different microbiota in vitro, in this case using the stools of the 7 volunteers from the previous study. And the experiment was a success! Only the stools of the sensitive patients hyper-reacted to the food emulsifier E466, making it possible to identify sensitive patients. This new approach could eventually allow us to predict the microbiota's response to certain emulsifiers.
What's more, sensitivity to the effects of E466 has been shown to be transmissible to mice, via fecal microbiota transplants. Flora from volunteers who are sensitive to E466 cause severe colitis in animals who consume the emulsifier, illustrating possible direct health consequences. These results also show the extent to which the bacteria in our microbiota can play an active role in the inflammatory response to certain additives.
A signature requiring refinement
It remained to be seen whether analyzing the DNA of the stool bacteria cocktail alone would be sufficient to predict sensitivity to E466. The researchers trained an algorithm to identify differences between the stool DNA of sensitive and non-sensitive volunteers. Results: 78 markers were counted. These bacterial markers, present in the microbiota of certain individuals, could predict sensitivity to emulsifiers. But this signature is not yet perfect: it worked in the clinical trial cohort, but its application to subjects from other studies has not yielded the expected results. Further studies are needed to validate this signature in wider populations.
While we wait for a universal signature that could facilitate screening, and thus avoid intestinal disorders in sensitive individuals, perhaps it's time to start cooking from scratch at home, especially since additives may also contribute to behavioral disorders. Not to mention microplastics in takeaway food packaging. We can't stress this enough: our diet is our primary medicine, and more sensible consumption, with unprocessed products, would also limit exposure to emulsifiers.
The bacteria of the microbiota are therefore much more than a simple reflection of our diet: they are also its main players. This study opens the way to personalized nutrition, based on the composition of our microbiota, and could help to better prevent certain disorders linked to the regular consumption of ultra-processed foods containing emulsifiers.
