The intestinal barrier is crucial for homeostasis. This study aimed to investigate the protective effects of earthworm protein hydrolysates (EWPH) on the intestinal mucosal barrier and elucidate the underlying mechanisms. We first hydrolyzed earthworm protein using alcalase and identified the primary peptide components of EWPH through Nano LC-MS/MS analysis. Network pharmacology and bioinformatics approaches were employed to predict potential targets associated with the intestinal mucosal barrier. Experimentally, we demonstrated that EWPH effectively protects against dextran sulfate sodium (DSS)-induced intestinal barrier damage in mice. The protective mechanisms involve not only the inhibition of the Toll-like receptor 4 (TLR4)-nuclear factor-κ (NF-κ)/mitogen-activated protein kinases (MAPK) signaling pathway in the intestinal epithelium but also the suppression of other key molecules implicated in intestinal mucosal barrier damage, including phosphorylated-SRC proto-oncogene (p-SRC), phosphorylated-signal transducer and activator of transcription 3 (p-STAT3), Caspase-3, and matrix metalloproteinase-9 (MMP9), thereby mitigating intestinal inflammation and mucosal barrier injury. This study provides evidence that EWPH have the potential to safeguard the intestinal barrier hemostasis.

Aluminum is the most abundant environmental pollutant. Recent studies suggest that aluminum exposure increases the risk of multiple diseases, including intestinal barrier dysfunction. We investigated whether Pueraria lobata extract (PLE) is effective in safeguarding against aluminum chloride exposure-exacerbated intestinal barrier dysfunction. Using an experimental colitis model of aluminum-exacerbated dextran sulphate sodium (DSS)-treated mice, clinical and pathological evidence suggested that the administration of PLE counteracted aluminum exposure-induced intestinal barrier damage. In addition, we found that aluminum toxicities, including loss of tight junction molecules (TJs), upregulated pro-inflammatory cytokines, and enhanced myeloperoxidase (MPO) activity, were significantly suppressed by PLE administration. Furthermore, PLE administration was identified to inhibit activation of MAPKs and NF-κB signal pathways, which contribute to upregulation of myosin light-chain kinase (MLCK) in inflamed intestine. Taken together, these results suggest that PLE might be a potential candidate for aluminum exposure-related intestinal barrier dysfunction.