Epithelial Barrier Theory

Original articles

Negative impact of common food emulsifiers on gut health

Mechanisms of gut epithelial barrier impairment caused by food emulsifiers polysorbate 20 and polysorbate 80

Ogulur I, Yazici D, Pat Y, Bingöl EN, Babayev H, Ardicli S, Heider A, Rückert B, Sampath V, Dhir R, Akdis M, Nadeau K, Akdis CA. Allergy. 2023 Aug 2. doi: 10.1111/all.15825.

Compounds present in everyday consumer products like processed foods, detergents, household cleaners and cosmetics have the potential to damage the protective cellular linings of the skin, respiratory tract and gut, which are referred to as epithelial barriers. This impairment can lead to microbial dysbiosis, bacterial migration, chronic microinflammation, and immune dysfunction. The concept of the epithelial barrier theory suggests that the widespread use of these barrier-damaging agents, including emulsifiers, surfactants, preservatives, and microplastics, is a key factor behind the significant and global increase in chronic health condition observed over the past 65 years.

Polysorbates are a type of nonionic surfactant often used in food preparation to improve the texture and consistency of foods, as well as to act as an emulsifier to help mix ingredients that might not otherwise blend well, such as oil and water. Originally incorporated as a food additive during mid-20th century, their utilization has since become widespread globally. Today, they are found in a wide range of processed foods, including ice cream, baked goods, salad dressings, and sauces, at concentrations up to 1%.

A comprehensive study by Ogulur et al. demonstrated the impact of P20 and P80, the most common types of polysorbates used in foods, on epithelial barriers and inflammatory response. Using human models, such as induced pluripotent stem cell-derived human intestinal organoids, colon organoids, organ-on-a-chips, and liquid-liquid interface cultures, it was revealed that P20 and P80 damage the gut barrier. This disruption is due to cell death and molecular toxicity, as well as the triggering of numerous genes and proteins that stimulate inflammatory responses in epithelial cells (known as ‘epithelitis’). The food emulsifiers also triggered a range of cellular processes, including tissue damage, alterations in cell signaling and communication, and induced inflammation. The study highlights that these effects occurred even at doses much lower than those approved for public use.

Considering that a defective epithelial barrier can facilitate the entry of allergens and induce an inflammatory response that can initiate or aggravate many chronic inflammatory diseases, the need to further evaluate the health hazards of these barrier-damaging compounds –– and the search for safer alternatives –– is all the more urgent. Read more.