Structural and functional alterations of intestinal flora in mice induced by halonitromethanes exposure

Abstract

Halonitromethanes (HNMs) as one typical class of nitrogenous disinfection byproducts (DBPs) have been widely found in drinking water and are receiving more and more attentions because of their high cytotoxicity, genotoxicity, and developmental toxicity. However, the effects of HNMs exposure on the intestinal tract and intestinal flora remain unknown. This study comprehensively determined the effects of trichloronitromethane, bromonitromethane, and bromochloronitromethane exposure on the intestinal tract and intestinal flora. Results showed that the three HNMs induced intestinal oxidative stress and inflammatory response. Further, HNMs exposure could change the diversities and community structure of intestinal flora, thereby triggering intestinal flora dysbiosis, which might be associated with the intestinal damage such as oxidative stress and inflammation. The intestinal flora dysbiosis was accompanied with mark alterations in function of intestinal flora, such as carbohydrate, lipid, and amino acid metabolisms. This research provides a new insight into studying the toxicity of HNMs exposure based on intestinal flora, which will further improve the health risk assessment of DBPs in drinking water.

Gastrointestinal Degradation and Toxicity of Disinfection Byproducts in Drinking Water Using In Vitro Models and the Roles of Gut Microbiota

“…Some studies have shown that DBPs could disrupt the balance of the microbial community and lead to dysbiosis. , However, it is unclear whether the lasting effects of DBPs on the gastrointestinal tract are related to DBP-induced dysbiosis. In this study, SHIME colonizing the gut microbiota made it possible to study the relationship among DBPs, the gut microbiota, and the gastrointestinal tract.…”

“…13 Several studies have shown that DBP exposure could affect the structure and function of the gut microbiota. 14,15 However, there are few reports on how exposure to DBPs affects the gut microbiota and thus indirectly produces enterotoxic effects. Due to the infeasibility of human exposure tests and ethical issues, the in vitro gastrointestinal simulation test method provides an opportunity to study the degradation of environmental contaminants in the gastrointestinal tract.…”

“…Additionally, the colon is colonized by an extremely complex gut microbiota with large biomass and high diversity, which is closely related to the human nutrient cometabolism and immune regulation. , Meanwhile, the gut microbiota is an important participant in the metabolism of environmental pollutants in the human gastrointestinal tract . Several studies have shown that DBP exposure could affect the structure and function of the gut microbiota. , However, there are few reports on how exposure to DBPs affects the gut microbiota and thus indirectly produces enterotoxic effects.…”