Dietary resistant starch ameliorating lipopolysaccharide-induced inflammation associated with alteration in gut microbiome and glucagon-like peptide 1 signaling

Background: Consumption of resistant starch (RS) has been associated with various intestinal and systemic health benefits, but knowledge of its effects on intestinal health and inflammatory response in stressed birds is limited. Here, we examined how dietary RS supplementation modulated inflammatory severity induced by lipopolysaccharide (LPS) in meat ducks. Results LPS administration at 14, 16, and 18 d (chronic challenge) decreased body weight and glucagon-like peptide 1 receptor (GLP-1R) with higher intestinal permeability and inflammation, evidenced by higher pro-inflammatory cytokine levels. Dietary RS supplementation enhanced Claudin-1 and GLP-1R expression, along with lower level of inflammatory factors in both ileum and serum. Microbiome analysis showed that RS treatment shifted microbial structure reflected by enriched the proportion of Firmicutes, Bifidobacterium , Ruminococcus , etc. Dietary RS addition also significantly increased the concentrations of propionate and butyrate during chronic LPS challenge. Further, handling LPS-challenge only at 14 d (acute challenge) confirmed LPS elevated the concentration of endotoxin and inflammatory cytokines in serum, accompanying with upregulated Toll Like Receptor 4 ( TLR4 ) transcription. Analogous to GLP-1 agonist liraglutide, dietary RS administration decreased endotoxins and inflammation cytokines, whereas it numerically increased serum GLP-1 level and upregulated the GLP-1 synthesis related genes expression. Meanwhile, dietary RS supplementation suppressed the acute LPS challenge-induced TLR4 transcription. Conclusions These data suggest that dietary RS supplementation could attenuate the LPS-induced inflammation as well as intestinal injury of meat ducks, which might involve in the alteration in gut microbiota, SCFAs production and the signaling pathways of TLR4 and GLP-1/GLP-1R.