Impact of polyunsaturated fatty acids, lipid oxidation products, haem-Fe and nitrite salt in muscle foods on oxidative stress and the colon microbiome in rats.

Red meat and fish are widely consumed, nutritious muscle-based foods with, however, opposing
epidemiologic associations with a range of chronic diseases. The underlying mechanisms are not
yet elucidated, but it is assumed that oxidative stress and alterations in the colon microbial
communities interfere. Previously, we showed through simulations of meat and fish
gastrointestinal digestion, that the fatty acid profile, haem-Fe, and nitrite salt in muscle foods
strongly influence the amount and type of formed oxidation products. Also, an influence of these
dietary factors on the colon microbial community is strongly suspected, yet not well explored. The
present research proposal will subject rats to some well-defined meat- or fish-based diets with
varying profiles of fatty acids and lipid oxidation products, haem-Fe, and nitrite salt. Special
interest will be given to the oxidation products 4-hydroxy-2-hexenal (from n-3 PUFAs) and 4-
hydroxy-2-nonenal (from n-6 PUFAs). The general goal of this project is to disentangle the
intertwining effects of these dietary factors on the colon microbial composition, oxidative stress
and associated events such as low-grade inflammation and insulin resistance. Furthermore, in the
colon tissue of rats, DNA adduct formation and the expression of selected genes will be measured
in the context of an already established research consortium.