Project description:The brown seaweed Laminaria digitata is a novel feedstuff for weaned piglets. It can help prevent dysbiosis in addition to improve overall health and performance. However, it has a recalcitrant cell wall that is not easily digested by the piglet digestive system. Alginate lyase has promising effects for the supplementation of in vivo diets in order to address this issue. The objective of this study is to evaluate the effect of 10% dietary Laminaria digitata inclusion and alginate lyase supplementation on the hepatic proteome and metabolome of weaned piglets in a physiological study. The diets caused incipient differences on the metabolome of piglets, with the proteome having the most significant changes. Feeding seaweed provided a source of n-3 PUFA that accumulated in the liver, signalling for increased fatty acid oxidation (FABP, ACADSB, ALDH1B1). This contributed at least in part to reduce oxidative stability of the tissue, demanding the higher abundance of GST to maintain it. Reactive oxygen species possibly damaged proteins, which caused hepatocytes to increase proteasome activity (LAPTM4B, PSMD4), recycling their amino acids. Providing alginate lyase to the diet increased the number of differentially abundant proteins, including GBE1 and LDHC that contributed to the maintenance of circulating glucose through mobilization of glycogen stores and branched chain amino acids. Enzymatic supplementation enhanced the baseline effects of feeding seaweed alone.
Project description:Laminaria digitata is a brown seaweed with prebiotic properties that has the potential to improve the response of weaned piglets to nutritional stress. However, its cell wall polysaccharides are not digested by the endogenous enzymes of monogastric animals. Alginate lyase has shown promise in degrading them under in vitro conditions. The objective of this study is to evaluate the effect of a 10% incorporation of L. digitata, and alginate lyase supplementation on the ileum proteome and metabolome, in a hypothesis generating approach. Control piglets increased the use of glucose as an enteric source of energy, demonstrated by the higher abundance of PKLR and PCK2 proteins and the lower concentration of glucose found in the tissue. Furthermore, seaweed inclusion promoted an increased abundance of proteins related with improved enterocyte structural integrity (ACTBL2, CRMP1, FLII, EML2 and MYLK), peptidase activity (NAALADL1, CAPNS1) and anti-inflammatory activity (C3), demonstrating improved intestinal function. Coherently, they lowered the abundance of apoptosis (ERN2) and proteolytic (DPP4) proteins. Alginate lyase supplementation seems to magnify the baseline effects of feeding the seaweed alone, by increasing the number of differential proteins in the same pathways, possibly as a consequence of increased intracellular nutrient release.
