Search Results (484)

Cats represent a susceptible host and a possible translational model for investigating coronavirus pathogenesis and therapeutics. Recent immunohistochemical (IHC) and histopathological studies in both human and feline tissues have demonstrated SARS-CoV-2 nucleocapsid protein (NP) and spike protein expression within pancreatic islet cells, following a classic temporal infection course. Notably, IHC analysis also reveals NP expression within exocrine ductal epithelial cells. Given that ductal epithelium functions as an islet progenitor pool during tissue injury or metabolic stress, pancreotropic coronaviruses may gain access to the endocrine compartment by exploiting this intrinsic cellular differentiation pathway. Although the precise mechanisms governing intra-islet viral entry remain to be elucidated, this review highlights the capacity of SARS-CoV-2 to compromise both the exocrine (digestive) and endocrine functions of the pancreas. Finally, we evaluate the therapeutic potential of direct-acting antivirals—specifically RNA-dependent RNA polymerase (RdRp) and protease inhibitors—as monotherapies and in synergistic combination to limit pancreatic injury and mitigate the diabetogenic effects of coronaviruses across both acute infection and post-acute sequelae, such as human long-COVID syndrome. Full article

As the prevalence of type 2 diabetes increases rapidly, the demand for natural origin dipeptidyl peptidase-IV (DPP-IV) inhibitors with fewer side effects is increasing. In this study, protein-rich Limnospira platensis was investigated as a source of bioactive peptides to enhance its value as a functional food ingredient. Hydrolysates were prepared using three food-processing proteases, individually and in two-step combinations, followed by in silico analysis and peptide identification via liquid chromatography–tandem mass spectrometry. Subsequently, the thermal stability, gastrointestinal resistance, and intestinal permeability (using Caco-2 cells) of the identified peptides were evaluated. It was revealed that the Orientase 22BF digest exhibited high DPP-IV inhibitory activity. From the digest, three novel peptides—SPSPN (IC₅₀ = 144.1 ± 2.2 μM), VPSV (IC₅₀ = 93.6 ± 5.8 μM), and IPIGG (IC₅₀ = 13.4 ± 2.3 μM)—were identified, exhibiting DPP-IV inhibitory potencies comparable to or higher than previously reported Limnospira-derived peptides. Although VPSV exhibited low epithelial permeability (P_app = 4.02 ± 0.69 × 10⁻⁸ cm/s), it remained stable under simulated gastrointestinal digestion conditions, suggesting potential local luminal inhibitory activity within the small intestine. Overall, these findings highlight Limnospira-derived VPSV as a promising functional ingredient candidate with high bioactivity and digestive stability. Full article

A total of 96 26-day-old weaned piglets were randomly assigned to four groups with three replicates per group: (1) CON group (basal diet), (2) PRS group (protease supplementation), (3) AMS group (amylase supplementation), and (4) combined protease and amylase group (PAS group) (protease and amylase supplementation). Compared to the CON group, AMS group reduced feed-to-gain ratio (p < 0.05). Additionally, all treatments increased ether extract digestibility (p < 0.05). The PRS and AMS groups reduced serum urea nitrogen level (p < 0.01). PAS group increased total protein, and decreased total cholesterol (p < 0.05). PRS and/or AMS supplementation increased serum glutathione peroxidase. IgM and IgG were higher in the AMS group. Furthermore, levels of D-Lactate and diamine oxidase were reduced (p < 0.05). PRS group exhibited increased fecal acetic acid and valeric acid levels (p < 0.05). Microbiota analysis showed that PRS or/and AMS supplementation enriched bacteria, including Anaerovoracaceae and Blautia. Metabolomics analysis revealed that health-promoting differential metabolites, including S-nitrosoglutathione and kynurenic acid, were further enriched, indicating enhanced immune regulation and intestinal homeostasis. Taken together, PRS or/and AMS supplementation can effectively promote nutrient digestion, intestinal microbiota structure and metabolism, and enhance intestinal barrier, thereby improving growth performance in weaned piglets. Full article

Protein utilization efficiency is a key determinant of metabolic health, body composition, and muscle function, particularly under high-protein dietary conditions and when using plant-based protein sources with lower digestibility. However, the extent to which enhancing early gastric proteolysis translates into improved whole-body protein utilization remains unclear. The present in vivo study investigated whether supplementation with an actinidin-enriched kiwifruit concentrate (Kwd+^®) modulates protein utilization efficiency and physiological outcomes under normoproteic and hyperproteic dietary conditions using casein or pea protein as dietary sources. Rats were fed normoproteic casein (NP), high-protein casein (CHP), or high-protein pea (PHP) diets with or without Kwd+^® supplementation for 8 weeks. Gastric protein hydrolysis patterns were evaluated by SDS–PAGE, while metabolic outcomes were assessed through body composition, plasma amino acid profiling, skeletal muscle morphology, and contractile function. Kwd+^® supplementation enhanced gastric proteolysis in a protein source-dependent manner. Despite the absence of significant changes in circulating amino acid concentrations after multiple comparison correction, Kwd+^® improved markers of protein utilization efficiency depending on dietary protein source. In animals fed a high-protein pea diet, supplementation significantly reduced fat mass relative to accumulated protein intake, indicating improved nutrient partitioning. In contrast, in animals fed a high-protein casein diet, Kwd+^® increased muscle mass relative to protein intake, suggesting enhanced anabolic efficiency. Under normoproteic conditions, Kwd+^® supplementation was associated with an increased muscle fiber cross-sectional area and improved fatigue resistance without alterations in fiber type composition or contractile protein abundance. These findings demonstrate that modulation of early gastric proteolysis through actinidin produces protein source-dependent effects on protein utilization efficiency, nutrient partitioning, and muscle function. This work highlights a novel nutritional strategy to improve metabolic outcomes and muscle performance, particularly in the context of high-protein and plant-based diets. Full article

Mast cells (MCs) are immune cells that produce numerous immunological mediators involved in inflammatory and allergic responses. Increased numbers of MCs are observed in chronic inflammatory reactions in organs such as the colon. There, MCs seem to participate in deleterious immune responses and tissue damage, but the detailed mechanisms of their activation are not known, mostly because procedures to obtain MC primary cultures from the colonic mucosa are expensive and time-consuming and present low yield. Here we describe a protocol to obtain MCs from the colonic mucosa (cmMCs) of C57BL/6 mice with high yield, viability and purity. Mucosal colon cells were dispersed by enzymatic digestion, and cmMCs were isolated by Percoll continuous-gradient centrifugation. This method allowed for the purification of 1,446,667 ± 112,442 cell/g of mucosal tissue, with 87.22% viability and 95.16% purity. The mucosal-like phenotype was predominant in isolated cmMCs, characterized by weak toluidine blue staining but strong expression of MC protease-1 (Mcpt1). Activation assays showed that freshly isolated cmMCs increased intracellular calcium and showed degranulation in response to ATP or IgE-antigen-dependent FcεRI cross-linking. This highly reproducible technique is cost-effective and requires no specialized equipment. This protocol could be applied in research related to inflammatory bowel disease, colon cancer or food allergies. Full article

This study developed a compound enzyme-assisted microbially fermented concentrate for Yanbian steers. The enzyme formulation was optimized using response surface methodology, with acid-soluble protein/crude protein ratio (ASP/CP), ammonia-N/total N ratio (AN/TN), and pH as response variables. The optimized enzyme preparation contained 619.15 U/g protease, 742.08 U/g amylase, and 257.75 U/g β-mannanase. The measured ASP/CP, AN/TN, and pH values were 31.74%, 3.56%, and 4.32, respectively, closely agreeing with the predicted values of 32.00%, 3.55%, and 4.28. Membership function analysis, which normalized positive and negative indicators to a common 0–1 scale and integrated them into a comprehensive score, supported the selection of day 5 as the most balanced fermentation duration under the primary equal-indicator weighting scheme. Thirty Yanbian steers were randomly assigned to receive microbially fermented concentrate without compound enzyme addition (MF) or compound enzyme-assisted microbially fermented concentrate (MEF) at 500 g/head/day on an as-fed basis for 100 days. After adjustment for initial body weight using ANCOVA, MEF increased final body weight by 3.9% and average daily gain by 35.7% compared with MF (both p < 0.001). MEF also increased dry matter intake by 12.1% (p = 0.018) and reduced feed conversion ratio by 18.4% (p = 0.008). MEF increased dry matter, crude protein, neutral detergent fiber, and acid detergent fiber digestibility by 4.3%, 5.4%, 22.6%, and 15.6%, respectively, and reduced blood urea nitrogen by 18.9%. MEF also increased ruminal total volatile fatty acids and decreased ruminal NH₃-N and the acetate-to-propionate ratio (p < 0.05). Observed ASVs, Chao1, and Shannon indices did not differ between treatments, whereas PERMANOVA detected a significant difference in overall rumen bacterial community structure (R² = 0.180, p = 0.023). VIF-based redundancy analysis indicated that variation in rumen bacterial community structure were correlated with crude protein digestibility, total volatile fatty acids, and blood urea nitrogen. Overall, within the microbial-fermentation system evaluated in this study, compound enzyme addition increased growth performance and apparent nutrient digestibility, reduced ruminal NH₃-N and blood urea nitrogen concentrations, and improved feed efficiency in Yanbian steers. Full article

Ulcerative colitis (UC) is a chronic inflammatory bowel disease marked by immune dysregulation, microbiota imbalance, and intestinal barrier damage. Unconjugated bilirubin (UCB) shows promise in treating UC due to its anti-inflammatory properties but is limited by poor solubility and potential toxicity. This study developed a chitosan-based controlled-release microsphere (CBMS) treatment to overcome these issues. CBMS utilizes the mucoadhesive properties of chitosan to achieve targeted, controlled UCB release in the colon, enhancing its stability and bioavailability. In a DSS-induced UC mouse model, CBMS alleviated clinical symptoms, reduced colon shortening, and improved histological outcomes, including reduced inflammation and enhanced mucosal repair. The mechanism involves CBMS retention in the intestinal lumen, UCB inactivation of digestive proteases, and restoration of microbiota balance, suppressing pro-inflammatory pathways. CBMS offers a promising new therapeutic strategy for UC and insights into polysaccharide-based drug delivery systems. Full article

Background: Adult Schistosoma mansoni parasites inhabit the hepatic portal system of the vertebrate host, their deposited eggs causing granulomatous pathology in both the intestines and liver. In the intestines, egg secretions drive inflammatory processes involved in extravasation to the gut lumen. Methods: Here, we investigate parasite-host interactions in a mouse model during the acute phase of a patent infection at 5 and 7 weeks, using parallel histological and proteomic analysis of paraffin-embedded ileal tissues. Results: Histology at week 7 showed infected animals had more inflammation and longer villi than at week 5, as well as more Goblet cells reflecting enhanced mucus production. LC-MS/MS analysis of deparaffinized ileal sections, subjected to in-solution tryptic digestion, revealed a total of 1615 protein groups. Differentially abundant proteins were found early at week 5, coinciding with the onset of egg deposition. A contrasting scenario, dominated by upregulation of protein components from the innate and adaptive immune systems, was seen at week 7; at this point, egg migration and excretion are underway. Among the proteins were mast cell proteases, fibrinogens, arginase-1, and molecules associated with extracellular matrix remodeling. Conclusions: Our findings reflect intestinal proteome changes likely participating in S. mansoni egg passage from the vascular bed to the intestinal lumen. Full article

Bovine milk contains bioactive proteins and encrypted peptide sequences whose abundance and availability may change during mammary or systemic inflammation. This narrative review critically evaluates evidence associated with subclinical mastitis, lameness-causing claw disorders, and periparturient metabolic disorders. Direct milk-level evidence is strongest for mastitis: increased somatic cell count and intramammary inflammation are generally associated with higher concentrations of milk haptoglobin, milk serum amyloid A (including mammary-associated serum amyloid A3, when isoform-resolved), lactoferrin, cathelicidins, and immunoglobulins, together with accelerated casein proteolysis. For lameness and metabolic disorders, evidence is substantially weaker and derives mainly from systemic acute-phase responses, broad milk metabolomic or compositional changes, and mechanistic hypotheses involving blood–milk barrier permeability and protease regulation. The review explicitly separates direct disease-defined milk evidence from systemic, broad omics, and mechanistic evidence. These alterations may influence biomarker performance, whereas processing consequences are best-established for mastitic milk. Their persistence after processing and digestion, and their biological effects in human consumers, remain largely unresolved. Future studies should combine diagnosis-specific cow health monitoring with milk proteomics and peptidomics. They should also assess the stability, bioaccessibility, and functionality of altered proteins and peptides during processing and digestion. Full article

Lentinus edodes stipe is an under-utilised processing by-product that holds potential as a natural umami source. This study systematically compared nine enzymatic hydrolysis combinations, including single proteases, cellulase, and double enzyme systems comprising both protease–protease and protease–cellulase mixtures, to optimise the release of taste-active and volatile flavor compounds from the stipes. The Flavourzyme-only hydrolysate achieved the highest degree of hydrolysis (50.38%), the richest 5′-nucleotides (5.46 mg/g), free amino acids (59.06 mg/g) and volatile compounds (150.23 μg/kg), and an equivalent umami concentration of 288 g monosodium glutamate equivalent per 100 g matter. It also delivered the strongest umami taste and the lowest bitterness in sensory evaluation. The double-enzyme systems consistently underperformed due to competitive substrate binding, suboptimal pH for companion enzymes, and potential mutual protease digestion. Among the volatile compounds, 1,2,4-trithiolane and cedrol were identified as key aroma differentiators by multivariate analysis. These findings demonstrate that Flavourzyme alone constitutes the optimal enzymatic system for producing clean-tasting, umami-rich condiments from L. edodes stipes and caution against indiscriminate enzyme blending without prior compatibility assessment. The optimized hydrolysis process provides a scalable route for the industrial valorisation of mushroom processing by-products. Full article

Butyrate, a short-chain fatty acid (SCFA), is increasingly recognized as a functional feed additive in aquaculture. However, its effects on crustacean health and performance remain unclear. This meta-analysis synthesizes findings from 23 studies (2011–2025) examining butyrate supplementation across four crustacean groups: shrimp, crabs, crayfish, and prawns. Effect sizes were calculated for growth performance (final body weight, specific growth rate, survival rate), feed efficiency (feed conversion ratio, protein efficiency ratio), and digestive enzyme activities (amylase, lipase, alkaline phosphatase, total protease) in freshwater and marine environments. Results indicate that butyrate supplementation generally enhanced the digestive enzyme activity in both freshwater and marine environments, although the magnitude of the effect varied among enzyme types and habitats, with freshwater species showing improvements in alkaline phosphatase, amylase, lipase, and total protease, and marine species showing improvements in amylase, lipase, and total protease. Feed efficiency improved in freshwater (protein efficiency ratio) and marine species (feed conversion ratio). Growth-related outcomes, including final body weight and survival rate, were generally improved across both environments. Dose–response analyses indicated that dietary inclusion levels of 1–2% were associated with the most consistent improvements in digestive enzyme activity and growth performance. These findings support the potential use of butyrate as a functional feed strategy to improve productivity and sustainability in crustacean aquaculture. These effects may be mediated by multiple mechanisms, including improved intestinal epithelial integrity, the modulation of gut microbiota, and the regulation of immune and metabolic processes. Full article

Helicoverpa armigera is one of the most destructive polyphagous pests, yet the transcriptional organization underlying its digestive capacity remains poorly resolved. Here, we compiled 579 publicly available RNA-seq libraries representing 54 independent experiments and quantified transcript abundance across tissues and developmental stages. This complete dataset was used to support broader tissue-level expression profiling. After metadata harmonization and quality filtering, a subset of 130 biologically comparable libraries from five tissue/developmental categories was retained for weighted gene co-expression network analysis. WGCNA identified four biologically informative modules, among which the turquoise module was positively associated with fourth- and fifth-instar larval midgut samples. Independent expression profiling revealed strong midgut-biased expression of several trypsin- and chymotrypsin-like serine proteases, although only a subset of these genes was assigned to the turquoise module. Descriptive functional annotation of this module identified 202 co-expressed loci, including digestive enzymes, nutrient transporters, detoxification-related proteins, epithelial components and putative transcriptional or signaling-associated genes. Phylogenetic analyses and manual inspection of genomic locations further showed that several digestive protease genes occur in local clusters and have closely related counterparts in H. zea, suggesting partial conservation of local genomic organization. Collectively, these results describe a midgut-associated co-expression module containing genes associated with digestive, absorptive and protective functions and provide candidate genes for future functional studies. Full article

This study assessed the effects of adding slightly acidic electrolyzed water (SAEW) to drinking water (0.3 and 0.6 mg/L) for 15 consecutive days on the growth performance, digestive enzyme activity, amino acid transporter gene expression, antioxidant activity, and immune function in weaned piglets. Using a randomized complete block design with pen as the experimental unit, 144 healthy weaned piglets were randomly assigned to three groups with four replicate pens per group according to weight and sex. During the entire experimental period, the average daily gain and average daily feed intake of the SAEW groups were significantly higher than those of the control (CON) group (p < 0.05). As compared to the CON group, the levels of α-amylase, β-amylase, lipase, and proteases in the duodenum increased in both SAEW groups (p < 0.05). Furthermore, 0.6 mg/L SAEW positively affected the mRNA levels of CAT1, PepT1, CAT2, EAAC1, rBAT, b0,+ AT, and 4F2hc in the jejunum and duodenum (p < 0.05). Regarding immune function, SAEW significantly decreased intestinal secretory immunoglobulin A levels in a dose-dependent manner (p < 0.05), while no significant changes were observed in serum immunoglobulin concentrations between the SAEW groups and the CON group. In terms of antioxidant status, SAEW significantly increased superoxide dismutase and glutathione peroxidase activities, but also increased malondialdehyde content in a dose-dependent manner. Despite the stronger promotion of intestinal amino acid transporters under 0.6 mg/L SAEW, this advantage failed to generate extra growth benefits alongside elevated oxidative damage. In conclusion, both tested SAEW concentrations exert positive effects on piglet growth and digestion; comprehensively balancing production benefits and redox safety, 0.3 mg/L SAEW is the optimal drinking water dosage for weaned piglets. Full article

Tilapia (Oreochromis niloticus) scales represent an underutilized by-product with considerable potential as a source of bioactive peptides that can be released through enzymatic hydrolysis. This study evaluated the production of protein hydrolysates from demineralized tilapia scales using Alkaline Protease or Esperase 8.0 L^® (Alkaline Protease and Esperase 8.0 L® were kindly provided by Novozymes, Bagsværd, Denmark), and examined the impact of simulated gastrointestinal digestion (SGID) on their bioactivities. The highest degree of hydrolysis (DH) was obtained with Alkaline Protease (12.4%), generating peptide fractions predominantly below 1000 Da, with a major population around 888 Da. Both hydrolysates exhibited antioxidant activity, with the Alkaline Protease hydrolysate showing higher ferric reducing antioxidant power (FRAP) and Fe(II)-chelating activity. The hydrolysates also displayed significant angiotensin-converting enzyme (ACE) inhibitory activity (IC₅₀: 13–14 µg/mL), dipeptidyl peptidase IV (DPP-IV) inhibitory activity (IC₅₀: 0.66–0.69 mg/mL), and prolyl endopeptidase (PEP) inhibitory activity (IC₅₀: 0.63–0.72 mg/mL). The digests were non-cytotoxic at the concentrations tested (<10 mg/mL) in STC-1 enteroendocrine cells. Following SGID, increased ACE-inhibitory activity was observed, with IC₅₀ values as low as 4.6 µg/mL, whereas DPP-IV and PEP-inhibitory activities decreased. The intestinal digest of the Esperase hydrolysate also exhibited significant cellular antioxidant activity in the ROS assay. Overall, these results indicate that tilapia scale hydrolysates are a promising source of peptides associated with in vitro enzyme inhibitory and antioxidant activities. However, the specific bioactive peptides responsible for these effects were not identified. Therefore, further studies involving peptide characterization, bioavailability assessment, and in vivo validation are required to establish their physiological relevance and potential applications as functional ingredients. Full article

The sea cucumber Apostichopus japonicus is of great economic value and is mainly cultivated in China. The application of formulated feeds has been widely used in massive sea cucumber aquaculture in recent years. With the attempt to investigate and evaluate the potential of mulberry leaf powder (MLP) as a dietary supplement for sea cucumber aquaculture (especially in winter), a 45-day feeding trail was carried out in winter in this study. Growth performance, digestive and redox-related enzyme activities, and the microbiota of intestinal contents were determined and compared between a basic diet and diets with different MLP-administration levels. The results showed that (1) MLP supplementation has a positive effect on the growth performance of sea cucumber; (2) increased activities of protease and lipase were observed in sea cucumber fed with MLP diets; (3) increased redox-related enzyme activities were observed in sea cucumber fed with 2% MLP diets; and (4) MLP supplementation has a regulatory effect on the diversity and relative abundance of microbiota in the intestinal contents of sea cucumber. The optimal dose of dietary MLP for growing sea cucumbers in winter was 2% dry weight. All data observed in this study will provide new clues for developing formulated feeds for massive sea cucumber aquaculture. Full article