Background: Glutamine peptides refer to a series of peptides containing glutamine, and the activity of glutamine peptides is characterized by the content of non-nitrogen terminal glutamine in the peptide. It has been found that glutamine peptides are a stable substitute for glutamine monomer, and they are increasingly studied in nutrition and physiology due to their functional properties. Methods: An extensive search of the literature was conducted in the PubMed, Web of Science, Scopus, and Google Scholar databases up to December 2024. Inclusion criteria focused on the role of glutamine peptides in intestinal health, and the included literature was screened and summarized. Results: This study systematically reviews the current status of research on the preparation, analysis, applications of glutamine peptides and their role in intestinal barrier protection. Furthermore, the challenges faced by the current research and the development direction in the future are discussed. Conclusions: Glutamine peptides can play a role in protecting the intestinal barrier by regulating tight junctions, mucin, inflammatory response, and intestinal flora. In addition, further and intensive investigations are urgently required to address the current challenges pertaining to the structure–activity relationships of glutamine peptides and their transport and absorption mechanism in the gut. This review contributes to a better understanding of the mechanism of glutamine peptides to protect intestinal barrier function and also provides a reference for the development of functional foods with protective effects of intestinal barrier function.

Objectives: This study investigated the antithrombotic properties of a fibrinolytic enzyme (CFE) purified from the culture supernatant of Coprinus comatus using a zebrafish thrombosis model. Methods: A phenylhydrazine-induced thrombosis model was employed to evaluate the in vivo thrombolytic efficacy and mechanisms of CFE. Results: CFE significantly attenuated thrombogenesis by inhibiting erythrocyte aggregation in the caudal vessels, reducing staining intensity (3.61-fold decrease) and staining area (3.89-fold decrease). Concurrently, CFE enhanced cardiac hemodynamics, increasing erythrocyte staining intensity (9.29-fold) and staining area (5.55-fold) while achieving an 85.19% thrombosis inhibition rate. Behavioral analysis confirmed improved motility, with CFE-treated zebrafish exhibiting 2.23-fold increases in total movement distance and average speed, alongside a 3.59-fold extension in active movement duration. Mechanistically, ELISA revealed the multi-pathway activity of CFE, promoting fibrinolysis through reductions in plasminogen, fibrinogen, and D-dimer; inhibiting platelet activation via downregulation of prostaglandin-endoperoxide synthase (PTGS), thromboxane A2 (TXA2), P-selectin, and von Willebrand factor (vWF); and modulating coagulation cascades through elevated protein C and tissue factor pathway inhibitor (TFPI) with concurrent suppression of coagulation factor VII (FVII). Conclusions: These results indicate that the fibrinolytic enzyme CFE, derived from Coprinus comatus, exerts potent antithrombotic effects, supporting its potential as a basis for fungal-derived natural antithrombotic functional food ingredients.

In this study, corn protein hydrolysates (CPT) were prepared via enzymatic hydrolysis using Alcalase and Protamex, and then fractionated by ultrafiltration into three molecular weight components: >5 kDa (CPT1), 3–5 kDa (CPT2), and <3 kDa (CPT3). The physicochemical, functional and in vitro antioxidant properties of each component were systematically compared. Subsequently, glutamine peptides were isolated and identified from CPT3 using LC-MS/MS technology, and the structural characteristics of the identified peptides were further analyzed. The results showed that the ultrafiltration fractionation effectively enriched peptides with lower molecular weights from the enzymatically hydrolyzed products, which may potentially enhance their bioavailability. In addition, CPT3 exhibited superior foaming ability, emulsifying ability, dispersibility, and zeta potential, along with lower particle size and viscosity. Moreover, CPT3 exhibited strong antioxidant activity, with IC₅₀ values for ABTS radical scavenging and hydroxyl radical scavenging of 0.042 ± 0.003 mg/mL and 0.807 ± 0.019 mg/mL, respectively. Finally, 205 glutamine peptides were further identified from CPT3, and their structural characterization revealed that the identified peptides were rich in hydrophobic amino acids and had a high affinity for membrane proteins, which could serve as potential ligands for regulating intestinal barrier dysfunction. In summary, CPT3 possesses excellent functional properties and antioxidant activity, indicating its potential for development and application in functional and health foods.