Abstract:The digestion, absorption, and utilization of sialic acid (SA) in the ready-to-eat peptide-containing and the traditional stewed edible bird’s nest products were compared. Male SD rats aged 8 weeks (n=32) were divided into four groups randomly, including blank control group (BC), peptide-containing edible bird’s nest group (PB), traditional edible bird’s nest group (TB), and sialic acid standard control group (SC). After oral gavage, the feces and urine were collected over 2 days to evaluate the absorption and retention of SA by calculating its digestion and absorption rates. Blood was collected intermittently during 60-day consecutive gavage to monitor the content alteration of the free and protein-bound SA in plasma and the erythrocyte membrane-bound SA, and the degree of sialyation was adopted to evaluate exogenous SA utilization. The results of the 2-day feces and urine monitoring did not reveal any significant statistical differences in SA digestion and absorption among all groups. The results of 60-day consecutive gavage revealed that the free SA concentration (P<0.005) and protein-bound SA content (P<0.005) in plasma and the erythrocyte membrane-bound SA content (P<0.001) were significantly higher in each intervention group compared to the BC group. After 10 days of intervention, the protein-bound SA content in the PB group was 36.36% higher than that in the BC group (P<0.05), and the erythrocyte membrane-bound SA in the PB group increased by 28.13% and 13.89% compared to the TB and SC groups (P<0.05), respectively. In conclusion, the sialylation of blood can reflect exogenous SA utilization and peptides can promote the utilization of SA. Long-term consumption of all types of edible bird’s nests can effectively improve the sialylation level of the body, surpassing the benefits derived from the intake of free SA.