Sensitivity to the additive E466: the role of the microbiota
When it comes to additives, some people are more sensitive than others. And this sensitivity, which varies from one individual to another, seems to be largely based on our gut microbiota. Does this mean that we can predict who is sensitive or not, based on a simple stool analysis?
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While (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 ) improve the texture and shelf life of many foods, they also raise health concerns. Some are suspected of promoting chronic inflammatory diseases by acting directly on our gut microbiota.
Nevertheless, the effects vary widely from one individual to another, according to a previous randomized controlled trial in humans (FRESH study: acronym for Functional Research on Emulsifiers in Humans). The additive used: (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 ) (or E466).
How can this sensitivity be explained or even predicted? The team 1 has continued its previous work by focusing on the microbiota. Their in vitro demonstration used a mini laboratory reactor capable of mimicking the human gut microbiota.
2500 The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has evaluated over 2,500 food additives, approximately 40 contaminants and naturally occurring toxicants, and residues of approximately 90 veterinary drugs. ²
The reactor predicts sensitivity or resistance
When the researchers exposed the microbiota collected from the FRESH study volunteers to carboxymethylcellulose in the bioreactor, they found the same difference in sensitivity as observed in vivo in the FRESH trial: the microbiota of the same 2 of the 7 volunteers exposed to E466 were disturbed when exposed to the emulsifier.
In other words, the microreactor faithfully reproduces the variations between individuals observed in the FRESH trial, making it possible to predict whether a given microbiota is sensitive to E466, without the need for in vivo studies..
Transplanted flora transmit sensitivity to mice
To confirm that this intestinal flora was responsible for the intestinal inflammation observed in some FRESH trial subjects exposed to E466, the microbiota of 2 E466-"sensitive" individuals and 2 non-sensitive individuals were transplanted into flora-free mice.
Only mice given the "sensitive" flora and exposed to the additive developed intestinal inflammation and severe colitis:
- shortening of the colon
- damage to the mucosa
- macrophage infiltration
Certain bacteria, including Adlercreutzia equolifaciens and Frisingicoccus caecimuris, were associated with this inflammation.
A signature?
It remained to be seen whether a
(sidenote:
Metagenomics
A method of studying the genetic material in samples taken directly from complex natural environments (intestines, oceans, soil, air, etc.), as opposed to samples grown in a laboratory. It produces a description of the genes contained in the sample, as well as an insight into the functional potential of the microbial community.
Source: Riesenfeld CS, Schloss PD, Handelsman J. Metagenomics: genomic analysis of microbial communities. Annu Rev Genet. 2004;38:525-52.
)
signature in stools could have predicted the outcome. Training an algorithm (with the stools of the 7 FRESH volunteers who had consumed E466) identified 78 functional markers of sensitivity.
This signature does make it possible to predict which individuals among the controls in the same study (those not exposed to E466) are sensitive to the additive. However, its application in other cohorts has not been conclusive.
Pending a possible signature, this study highlights new links between the gut microbiota and healthy eating. It also points to the need to consume fewer ultra-processed products (which, like some sweeteners, appear to be detrimental to the health of the gut microbiota).
