Evaluation of the impact of the dietary inclusion of salty and sugary former food products on the liver and plasma profile of pigs through OMICS approaches

The research on alternative and sustainable feed ingredients is a challenge to reduce feed-food competition between humans and monogastrics, in particular pigs. Former food products (FFPs) drop out from the industrial production of food such as pasta, bread, snacks, and chips. They have a high nutritional and energetic value and represent an alternative and sustainable feed ingredient. The aim of this study was to apply omics tools to assess the impact of the dietary inclusion of FFPs in pigs’ diet. For the in vivo trial, thirty-six Swiss Large White male castrated pigs were randomly assigned to three dietary groups: control (CTR), 30% replacement of CTR diet with salty FFPs (SA), 30% replacement of CTR diet with sugary FFPs (SU). The trial lasted from the start of the growing phase (22.4 ± 1.7 kg) until slaughtering phase (110 ± 3 kg). After slaughtering, blood and liver tissue samples were collected and processed according to the omics approaches used. The number of differentially regulated proteins in each comparison matrix (SA/SU vs. CTR) indicated a marginal impact on liver function, as measured by proteomics on tissue samples. The peptidomics investigation on plasma samples showed low variability between the peptidome of the three dietary groups and identified three possible bioactive peptides associated with anti-hypertension in the SA dietary group. To conclude, the safety and the limited impact of the SA and SU diets on liver proteome and plasma peptidome strengthened the idea of recycling FFPs as feed ingredients to make pig production more sustainable.