Epithelial Barrier Theory

Original articles

Negative impact of professional dishwasher rinse aid on gut health

Gut epithelial barrier damage caused by dishwasher detergents and rinse aids.

Ogulur I, Pat Y, Aydin T, Yazici D, Rückert B, Peng Y, Kim J, Radzikowska U, Westermann P, Sokolowska M, Dhir R, Akdis M, Nadeau K, Akdis CA. J Allergy Clin Immunol. 2023 Feb;151(2):469-484.

According to the epithelial barrier theory, exposure to many toxic substances in humans and animals damages the epithelium, the thin layer of cells that covers the surface of our skin, lungs and intestine. A number of diseases, including food allergy, esophagitis, gastritis, diabetes, obesity, fatty liver, autoimmune hepatitis, liver cirrhosis, rheumatoid arthritis, multiple sclerosis, autism spectrum diseases, chronic depression, Alzheimer’s and Parkinson’s diseases have been linked to defective epithelial barriers in the digestive system and dysbiosis in the microbiota particularly in the gut. In general, it has been proposed that damaged epithelial barriers contribute to the pathogenesis of two billion patients.

Professional dishwashers have become the state of the art for dishwashing in public places including restaurants, schools, military and hotels throughout the whole world. A comprehensive study by Ogulur et al. demonstrated the toxicity of professional dishwasher rinse aids. The substance responsible for this damage was pinpointed as alcohol ethoxylates present in the rinse aid. Using human models, such as induced pluripotent stem cell-derived human intestinal organoids, organ-on-a-chips and liquid-liquid interface cultures, the health hazard of exposure to professional and household dishwasher detergent and rinse aid, and its individual components on cytotoxicity, barrier function, transcriptome and protein expression was investigated.

A worldwide commonly used ingredient, alcohol ethoxylates in the professional dishwasher rinse aid was killing gut epithelial cells in 1:20’000 dilutions. The underlying mechanisms of the epithelial barrier disruption in response to professional dishwasher rinse aid are cell death in high doses and epithelial barrier opening in low doses together with activation of multiple genes and proteins that induce inflammatory responses in the exposed cells. One of the most exciting findings of the present study is after a finalized dishwashing, the researchers were able to extract a significant amount of remaining toxic substances from the washed and ready to use dishware. These findings, which mark the beginning of intestinal epithelial disruption and inflammatory responses in many chronic diseases, may have an important impact on public health. It is now so important to make the public aware of this toxicity and take immediate measures as apparently this substance is commonly used in professional dishwashers. Read more.