Multi-omics analysis revealed coordinated responses of rumen microbiota and epithelium of goats to dietary supplementation of glucosamine selenium

Selenium (Se) is one of the essential trace elements for ruminants. The impact of varying dietary Se levels on rumen epithelium and microbiota remains inadequately studied. This study used multi-omics techniques to investigate the coordinated response of rumen microbiota and epithelium to dietary glucosamine selenium (GASe) supplementation. Sixty female Wanlin White goats (19.90 ± 2.00 kg) at 4 months of age were randomly divided into 4 groups with 15 replications of 1 goat each. Goats in the control (CON), and the low (L), medium (M) and high does (H) groups were supplemented GASe at 0, 0.6, 1.2 and 2.4 mg Se/kg, respectively. After a 60-d feeding trial, 5 goats per group were randomly selected for slaughter and sampling. The results showed that average daily gain, rumen papilla length, and glutathione peroxidase (GPx) activity in the L group were significantly higher than those in the CON and H groups (quadratic; <i>P</i> < 0.05). Microbial analysis revealed that <i>unclassified_Christensenellaceae</i> (quadratic) had higher (<i>P</i> < 0.05) abundances in the L group and showed significant positive correlations with rumen papilla length and GPx activity (<i>P</i> < 0.05). In contrast, the abundances of pathogenic <i>Campylobacter</i> were highest in the H group (linear or quadratic; <i>P</i> < 0.05). Weighted gene co-expression network analysis (WGCNA) identified the gene module MEturquoise and the compound module ME6 as significantly associated with papilla length and GPx activity (<i>P</i> < 0.05). Genes in the MEturquoise module were enriched in ribosome, oxidative phosphorylation, RNA polymerase, and nucleotide sugar biosynthesis pathways, while the ME6 module was mainly associated with amino acid and nucleotide metabolism. Multi-omics analysis revealed that metabolic responses bridged transcriptional regulation and microbial dynamics. Additionally, 2 microbiota-derived substances, actinorhodin and dimethylpropiothetin, were significantly associated with papilla length and GPx activity (<i>P</i> < 0.05). In conclusion, an appropriate amount of GASe can improve goat growth performance, promote rumen epithelial growth and health by enhancing cellular metabolism and increasing beneficial bacteria abundance. However, excessive GASe supplementation may reduce rumen epithelial antioxidative and metabolic capacities, and promote pathogenic bacteria proliferation. Furthermore, this study demonstrates that metabolites mediate the coordinated response of the rumen microbiota and host to dietary GASe supplementation. Supplementation of 0.598 to 0.832 mg Se/kg GASe in the diet is recommended for goats.