Acute Exposure to Commonly Ingested Emulsifiers Alters Intestinal Mucus Structure and Transport Properties

Abstract

The consumption of generally regarded as safe emulsifiers has increased, and has been associated with an increased prevalence of inflammatory bowel and metabolic diseases, as well as an altered microbiome. The mucus barrier, which selectively controls the transport of particulates and microorganisms to the underlying epithelial layer, has been previously shown to be altered by dietary salts and lipids. However, the potential impact of emulsifiers on the protective mucus barrier, its permeability, and associated structural changes are not clear. In this study, we analyzed changes in the mucus barrier to both passively diffusing nanoparticles and actively swimming E. coli upon exposure to two emulsifiers, carboxymethylcellulose (CMC) and polysorbate 80 (Tween). When exposed to CMC, mucus pore size decreased, which resulted in significantly slower E. coli speed and particle diffusion rates through mucus. Tween exposure minimally impacted mucus microstructure and particle diffusion, but increased E. coli speed in mucus. Moreover, both emulsifiers appeared to alter mucus amount and thickness in rat intestinal tissue and mucus-producing cell cultures. These results indicate that acute exposure to emulsifiers impacts barrier and structural properties of intestinal mucus, modulating interactions between intestinal lumen contents, microbes, and underlying tissue, which may contribute to development of intestinal inflammation.

Gut microbiota, dietary intakes and intestinal permeability reflected by serum zonulin in women

“…Furthermore, besides micro- and macronutrients, food additives such as emulsifiers should be carefully monitored in future studies as they could negatively influence the gut barrier [52]. …”

“…Another major influence factor which should be carefully considered in future studies is the effect of food combinations, which could lessen the unfavorable effects of dietary fat and protein such as flavonoids, prebiotics and probiotics. Furthermore, besides micro- and macronutrients, food additives such as emulsifiers should be carefully monitored in future studies as they could negatively influence the gut barrier [ 52 ].…”

Impact of Developmental Age, Necrotizing Enterocolitis Associated Stress, and Oral Therapeutic Intervention on Mucus Barrier Properties

“…Escherichia coli MG1655 (E. coli, ATCC ® 700926 ™ ) was transformed with a plasmid containing green fluorescent protein (GFP) and ampicillin resistance gene (gift from Marcia Goldberg, Harvard Medical School) using standard heat-shock protocol to obtain fluorescent E. coli for tracking 70 . Briefly, a 16 hr overnight culture of E. coli www.nature.com/scientificreports www.nature.com/scientificreports/ was diluted 1:100 in Luria Bertani (LB) broth (Fisher BioReagents ™ ) and cultured for 2 hrs.…”

“…A standard curve of bovine serum albumin (0-2000 µg/ml) was used to calculate sample protein amount. Mucin amount was quantified using an alcian-blue assay 70,75 . Each sample or standard (0-250 µg/ml of mucin from bovine submaxillary glands, Sigma Aldrich) was added (100 µl) in triplicate to a 96 well plate followed by 33.3 µl of alcian blue (Sigma Aldrich).…”

Mannosylated Nanoparticles for Oral Immunotherapy in a Murine Model of Peanut Allergy

“…This result may be explained by a rapid release of peanut extract components located on the surface of the nanoparticles and their disturbing effects on the structural properties of the mucus gel. In fact, peanut proteins possess important emulsifying properties and oil binding capabilities 40 that may negatively affect to the viscoelastic properties of mucus 41 . These effects, as well as their resistance to enzymatic degradation, would facilitate the ability of some peanut proteins (e.g., Ara h2, Ara h6, Ara h7, oleosins) to cross the mucus barrier and the intestinal epithelium, before exposition to underlying immune cells [42][43][44] .…”