Polysorbate 80 and carboxymethylcellulose: A different impact on epithelial integrity when interacting with the microbiome.

The consumption of dietary emulsifiers, including polysorbate 80 (P80) and sodium carboxymethylcellulose (CMC), has raised safety concerns due to its interaction with the intestinal microbiome. This study demonstrated that increasing concentrations of P80 and CMC added to a dynamic four-stage gut microbiota model (BFBL gut simulator) altered the microbiome composition and impacted epithelial integrity in a dose-dependent manner. 16S rDNA amplicon-based metagenomics analysis revealed that these emulsifiers increased microbial groups with proinflammatory capacities while decreasing microbial taxa known to enhance barrier function. Increasing doses of P80 significantly decreased Bacteroides dorei and Akkermansia, taxa associated with anti-inflammatory potential, while increasing doses of CMC were linked to a higher abundance of Ruminococcus torques and Hungatella, which negatively impact barrier function. Both emulsifiers displayed a different impact on epithelial integrity when interacting with the microbiome. On one hand, supernatants from the BFBL simulator fed with P80 disrupted epithelial integrity to a lesser extent than the additive alone. On the other hand, both the microbiota and the supernatants from the BFBL simulator fed with CMC diminished the epithelial integrity, though the additive itself did not. These findings highlight the need to incorporate the gut microbiome in the risk assessment of these additives.