Meat and fish are protein sources rich in sulfur-containing amino acids, which are essential in the diet When sulfur compounds enter the large intestine, the growth of sulfate-reducing bacteria (SRB) is promoted, favoring the formation of hydrogen sulfide (H2S), a key regulator of intestinal health High concentrations of large intestinal H2S may damage the intestinal mucus layer, leading to inflammation and DNA damage Present proposal will investigate the influence of different meat characteristics (eg protein oxidative stability and digestibility) and other dietary compounds on the outgrowth of SRB and formation of H2S and other sulfur-containing compounds First, in vitro digestion studies will be conducted to gain insight in oxidative and proteolytic reactions during enzymatic digestion of meat, and in the formation of volatile sulfur compounds during large intestinal fermentation, in interaction with other food compounds (WP1) Next, rats will be subjected to meat- or fish-based diets in three feeding experiments (WP2), after which the large intestinal microbial community will be characterized, along with an evaluation of intestinal histology, DNA adducts, inflammation and oxidative stress parameters (WP3) The larger goal is to elucidate the mechanisms responsible for the association between high red and processed meat consumption and various chronic diseases, in order to develop nutritional strategies to reduce these health risks