Gut microbiome of Sprague-Dawley rats treated with iodoacetic acid

Carcinogenicity of disinfection by-products (DBPs) is of great concern for daily exposure via drinking water. Iodoacetic Acid (IAA) is an emerging and unregulated DBP that has been reported to have potent cytotoxicity and genotoxicity in several lines of mammalian cells. However, no direct evidence about the carcinogenicity of IAA is available. Here we confirmed that IAA is a carcinogen by the OECD-recommended chronic toxicity test. In addition, we found that long-term exposure to IAA significantly altered gut microbiome composition especially in reducing the relative abundance of Lactobacillus in experimental animals, which may impair the intestinal barriers of rat gut and potentially contribute to the incidence of thyroid cancer and pituitary adenoma.