Abstract
The host-gut microbiota relationship is an important determinant of intestinal homeostasis, and perturbations in this equilibrium are associated with numerous chronic inflammatory diseases such as inflammatory bowel diseases (IBD) and metabolic syndrome. Intestinal microbiota perturbations can be triggered by environmental factors, especially through dietary habits. Ultra-processed food, which includes many synthetic and non-nutritional ingredients such as dietary emulsifiers, is associated with alterations in microbiota composition as well as a higher risk for development of IBD.
Among the food additives used by the food industry, dietary emulsifiers are widely used in order to improve organoleptic properties and extend shelf-life, with the most commonly used being lecithin, mono- and diglycerides of fatty acids, guar gum, xanthan gum, carrageenan, polysorbate-80 (P80) and carboxymethylcellulose (CMC)(109,110). In recent years, dietary emulsifiers have received particular attention due to their possible implication in the pathogenesis of IBD and metabolic dysregulations.
When investigating their impact on the development of chronic inflammatory disease, several studies from Dr. Chassaing's and other laboratories have revealed that the administration of CMC and P80 to mice is sufficient to drive microbiota alterations in a way that increases its pro-inflammatory potential. Furthermore, emulsifiers consumption is sufficient to induce microbiota encroachment, characterized by microbiota penetration of the normally sterile mucus layer lining the intestinal mucosa. Altogether, these microbiota alterations ultimately lead to chronic intestinal inflammation which manifest as colitis in genetically susceptible host and metabolic dysregulations in wild-type host.
Moreover, a recent double-blind controlled-feeding study investigated the impact of CMC consumption on the intestinal microbiota and intestinal health in healthy human participants. Results obtained demonstrated that CMC consumption is sufficient to detrimentally alter the intestinal microbiota composition and fecal metabolome, suggesting the dire need for further studies focusing on the role played by long-term emulsifier consumption in healthy individuals as well as in various diseases characterized by a chronic intestinal inflammation state (IBD, metabolic syndrome, etc....).
