Hydroxypropyl starch enhances gut health in geese.

This study aimed to investigate the effects of hydroxypropyl starch (HPS) on intestinal morphology, serum biochemical parameters, gut microbiota, and ileal content metabolome in Yangzhou geese. A total of 240 30-day-old Yangzhou geese with similar body weight were randomly assigned to three groups: control group (CG), hydroxypropyl starch group (HS), and sodium urate group (SU). Each group had four replicates with 20 geese per replicate. After a 21-day feeding period, serum, kidney, and terminal ileum samples were collected for analysis. The results showed that HPS reduced serum uric acid levels and improved intestinal structural integrity, although the changes in both parameters did not reach statistical significance (P > 0.05), but showed a certain trend of improvement. Histological examination revealed that the HS group maintained intact cell morphology with no inflammatory cell infiltration, cell infiltration, or glomerular epithelial cell shedding. In contrast, the CG group exhibited nearly complete shedding of glomerular epithelial cells, enlarged intercellular spaces, and some cell infiltration, while the SU group showed glomerular epithelial cell shedding, blurred cell boundaries, and presence of inflammatory cells. HPS supplementation exhibited a tendency to increase the operational taxonomic unit (OTU) index, and significantly increased the abundance of Rothia (P < 0.05). Ileal content metabolomics analysis revealed that in the HS group, differentially expressed metabolites were mainly enriched in multiple amino acid biosynthesis pathways, with cysteine identified as a key metabolite (P < 0.05); whereas in the SU group, differentially expressed metabolites were mainly enriched in the primary bile acid biosynthesis pathway, with bile acids as key metabolites (P < 0.05).