Differentially expressed proteins in the blood serum of piglets in response to a diet supplemented with inulin

In the present study we introduced a two-dimensional electrophoresis and matrix-assisted laser desorption/ionisation time of flight mass spectrometry-based proteomic workflow to identify proteins that show altered expression as a result of the addition of 2% of water extract of inulin-type fructans to the diet of growing piglets. This analysis allowed us to detect an average of 240 spots per gel with a mass range from 10 to 250 kDa and a pH ranging from 3 to 10. Twenty protein spots were found to show statistically significant differences in their expression. Of these, 7 protein spots were up-regulated, whereas 13 showed down-regulation in response to the experimental diet. In total, 13 spots were identified, representing 8 distinct gene products. The experimental diet caused a significant change in proteins directly or indirectly involved in hemostasis and the innate immune response. Increased levels of fibrinogen along with decreased plasminogen expression may indicate that a fructan-rich diet favours the deposits of fibrin and promotes blood clotting. We also found increased expression of vitronectin and the alpha subunit of the complement component C8 which may protect the host organism against excessive cytolitic activity of the activated complement. The piglets from the experimental group had slightly increased values of IgG and IgA, whereas the IgM level tended to be decreased. The fructan-rich diet did not have any influence on plasma total cholesterol, HDL and LDL cholesterol and triglyceride levels.