Edible bird’s nest (EBN), abundant in sialic acid (SA) has been recognized as a natural substance beneficial to brain development and cognitive ability. In order to investigate active component of EBN, sialylated glycopeptides (SCP) were extracted from EBN by 60% ethanol after trypsin hydrolysis and its effects on central nervous system was evaluated in lipopolysaccharide (LPS)-induced neuroinflammation mice. EBN, SCP, and SA pretreatment and intervention reduced interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels in hippocampus and cortex, meanwhile inhibited the activation of microglia, astrogliosis and neuron apoptosis, which were consistent with the learning and memory improvement and anti-depression effects in behavioral tests. The counts of leukocytes, neutrophils and monocytes, as well as IL-1β, TNF-α, and IL-6 levels in peripheral circulation were significantly reduced by SCP. Results of plasma metabolomics suggested SCP up-regulated energy metabolism, promoted the recovery of primary and secondary bile acid metabolism and indole metabolism, where microbiota may involve. 16S rDNA sequencing of colonic contents showed EBN, SCP and SA repaired dysbacteriosis in LPS-treated mice by significantly up-regulating the anti-inflammatory Muribaculaceae and inhibiting pro-inflammatory related Desulfovibrio and Candidatus_Saccharimonas. In addition, both EBN and SCP could significantly enrich Aerococcus, while SA could specifically enrich Prevotellaceae_UCG_001. The gut-brain axis was preliminarily established, and SCP may have the potential to be a functional factor for neuroprotection applied in EBN industry.

Skin is an important barrier organ of the human body. As we age, the appearance and function of our skin deteriorate, which poses health risks. The use of edible bird's nest (EBN) to nourish the skin is an ancient method in Asia. However, the role and mechanism of EBN products in improving human skin aging are still unclear. Therefore, we conducted a randomized controlled trial that included 92 healthy female volunteers aged 25–45 years. They were randomly divided into the high-dose group, the low-dose group, and the control group, and they completed a 12-week treatment. The results showed that the consumption of high-dose EBN significantly improved skin moisture and elasticity by 22.14% and 5.89%, respectively, and significantly reduced the number of deep wrinkles, light wrinkles and spot area by 18.47%, 0.64%, and 3.05%, respectively. ELISA results showed that EBN decreased the expression of inflammatory factors (IL-6 and TNF-α) and serum factors (NO, MMP-1, MMP-9). Moreover, EBN can reverse the aging-induced decreases in SOD and LOX, thus slowing down the aging process. Fecal metagenome results showed that EBN significantly increased the abundance of beneficial bacteria (Bacteroides_uniformis and Bacteroides_finegoldii). Serum and fecal non-target metabolomic results showed that EBN significantly increased serum and fecal metabolite (N-methylnicotinamide, 2-deoxyribose 5-phosphate, and dimethylmalonic acid) concentrations compared with the control group. Furthermore, correlation analysis revealed a positive association between N-methylnicotinamide levels and skin elasticity. These findings suggest that EBN may ameliorate skin aging by enhancing the diversity of beneficial gut bacteria and their metabolites.