Search Results (2,353)

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

This study was designed to assess the protective efficacy of dihydromyricetin (DHM) against intestinal injury in Chinese soft-shelled turtles (Pelodiscus sinensis) caused by partial replacement of fishmeal (FM) with fermented rapeseed meal (FRM), and to uncover the molecular mechanisms involved. Turtles were fed an FM-based control diet, an FRM-substituted diet, or FRM diets supplemented with DHM at 0.5‰ (DHMT1), 1.0‰ (DHMT2) or 2.0‰ (DHMT3) for 8 weeks. Growth performance, digestive enzyme activities, antioxidant parameters, inflammatory cytokines, and intestinal histomorphology were assessed, and intestinal transcriptomics and metabolomics were also performed. FRM replacement significantly improved growth performance; however, this beneficial effect was accompanied by notable intestinal mucosal oxidative damage, as evidenced by decreased villus height, increased lumen space, and lamina propria edema, along with elevated pro-inflammatory cytokines (IL-1β and TNF-α) and MDA content, alongside reduced GSH and CAT activities. DHM supplementation dose-dependently ameliorated these adverse effects by restoring mucosal integrity, digestive enzyme activities, redox homeostasis, and inflammatory balance, ultimately improving growth performance. Transcriptomic KEGG analysis revealed that DHM enriched pathways related to glycerophospholipid metabolism, glutathione metabolism, drug metabolis-cytochrome P450, and polyunsaturated fatty acid metabolism. Metabolomics further confirmed dose-dependent remodeling of phospholipids and bile acids. Integrated omics demonstrated that DHM likely regulates detoxification, anti-inflammatory, membrane repair, and antioxidant pathways. In conclusion, DHM demonstrates a protective effect against FRM-induced intestinal mucosal oxidative damage in P. sinensis, which may be mediated by a synergistic combination of enhanced detoxification, anti-inflammatory modulation, restoration of phospholipid membrane integrity, and reinforcement of antioxidant defenses. Full article

Marine rest raw materials are often undervalued or wasted despite their nutrient and bioactive composition. Calanus finmarchicus, harvested primarily for its omega-3-rich oil, yields a side-stream protein hydrolysate, C. finmarchicus hydrolysate (CFH), during commercial enzyme-assisted extraction. Although currently used as a feed ingredient, CFH contains low-molecular-weight peptides and free amino acids with potential for human health applications. This study evaluated the gastrointestinal stability of CFH and the impact of digestion on bioactivity using a static in vitro gastrointestinal digestion model. Fresh-frozen and freeze-dried C. finmarchicus were included to provide comparative data. Antioxidant capacity was measured by ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assays, and antidiabetic activity by dipeptidyl peptidase-IV (DPP-IV) and protein tyrosine phosphatase 1B (PTP1B) inhibition assays. The hydrolysate maintained its antioxidant capacity throughout digestion (at 165 min: FRAP: 27.5 ± 0.6 µmol TE/g dry weight (DW); ORAC: 411 ± 37 µmol TE/g DW). Digestion increased its DPP-IV inhibitory activity, with the inhibitory concentration (IC₅₀) decreased from 3.73 to 1.96 mg/mL (p ≥ 0.05). PTP1B inhibitors were nonselective and detected only at 0 and 30 min. These findings support our hypothesis that CFH may serve as a nutraceutical for humans and provide a rationale for subsequent in vivo studies. However, further identification of bioactive components and in vivo validation are warranted. Full article

Medicinal plants are being investigated as a source of compounds with biological activities related to diabetes. The antidiabetic properties of the plant Carica papaya have been reported in experimental models. This study aimed to evaluate the phytochemical composition, antioxidant activity, and inhibitory activity of extracts from C. papaya leaves against α-glucosidase and pancreatic lipase. Plant material was collected in Tabasco, Mexico, and extracted by sequential maceration with solvents of increasing polarity: hexane, dichloromethane, methanol, and methanol:water. The extracts were fractionated by column chromatography, and the most active fractions were selected for further purification. The phytochemical identification of the active compounds was performed, and their structures were elucidated using spectroscopic and spectrometric techniques. The methanolic extract, rich in phenols and flavonoids, showed the highest antioxidant capacity (DPPH: 8.99 mmol TE/g; ABTS: 35.94 mmol RE/g; FRAP: 48.62 mmol Fe²⁺/g). The hydroalcoholic extract exhibited α-glucosidase inhibitory activity (38.44%), and bioassay-guided fractionation led to the identification of clitorin. The dichloromethane extract showed pancreatic lipase inhibition (52.2%), and the most active fraction contained loliolide. These findings demonstrate that C. papaya leaves contain bioactive compounds with antioxidants and digestive enzyme inhibitory activities, suggesting they could be candidates for further research in the management of diabetes. 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

Saline–alkaline aquaculture is a promising strategy to alleviate freshwater shortages; however, such environments severely impair fish growth and physiological homeostasis. Nutritional regulation has been proposed to improve stress tolerance, yet the benefits of single additives are often limited under the multifactorial challenges imposed by saline–alkaline conditions. Therefore, a compound feed additive (CFA) consisting of glutamate, cholesterol, β-glucan, myo-inositol, zinc methionine, and curcumin was developed and evaluated in Nile tilapia (Oreochromis niloticus). To assess the robustness and practical applicability of this nutritional strategy, three independent feeding trials were conducted using different commercial basal diets as validation systems. Within each dietary system, fish were reared under freshwater (FW), saline–alkaline water (SAW), or saline–alkaline water supplemented with CFA (SAW+CFA). Saline–alkaline stress significantly reduced WG and SR, increased FCR, and elevated VSI and HSI, indicating impaired growth performance and metabolic burden. These changes were accompanied by increased serum glucose and ion concentrations (Na⁺, K⁺, Cl⁻), elevated ammonia levels, and reduced crude protein content. Dietary CFA improved growth and feed utilization under saline–alkaline conditions. It enhanced hepatic glycogen content and reduced serum glucose levels. Meanwhile, it downregulated glycolysis-related genes (hk, pfk1, pk) and upregulated genes involved in gluconeogenesis and the pentose phosphate pathway (g6pase, pc, g6pdh), indicating altered glucose metabolism and improved energy homeostasis. Saline–alkaline stress induced oxidative stress, apoptosis, and histological damage in the liver, whereas CFA alleviated these alterations by reducing MDA levels, enhancing antioxidant enzyme activities (CAT, GSH-Px, T-SOD) and suppressing apoptosis-related genes (caspases, p53, c-myc). In addition, CFA alleviated saline–alkaline stress-induced gill structural damage and reduced serum ion concentrations while modulating ion transport-related gene expression, suggesting improved osmoregulatory capacity. It also enhanced ammonia metabolism and transport, as reflected by reduced serum ammonia levels and altered expression of related genes. Furthermore, Saline–alkaline stress impaired intestinal structure and function, whereas CFA improved intestinal villus structure, increased digestive enzyme activities (amylase, trypsin, lipase), and suppressed pro-inflammatory genes (il-1β, il-8). Importantly, similar beneficial response patterns were observed across the three independently analyzed dietary systems. Overall, CFA improved saline–alkaline adaptability of Nile tilapia and was associated with improvements in energy metabolism, oxidative homeostasis, osmoregulation, ammonia detoxification, and intestinal function, providing a practical nutritional strategy for saline–alkaline aquaculture. Full article

Momordica charantia L. is a medicinal plant rich in bioactive compounds, including steroidal glycosides, flavonoids, phenolics, triterpenoids, saponins, and polysaccharides, which exhibit antidiabetic, antioxidant, anti-inflammatory, hepatoprotective, and anticancer activities. This review summarizes its nutritional and phytochemical composition, green extraction technologies, molecular mechanisms, and industrial applications based on literature from Google Scholar, PubMed, Scopus, Web of Science, ScienceDirect, and other scientific databases. Ultrasound-assisted extraction is an efficient and eco-friendly method that provides higher recovery of bioactive compounds from M. charantia and improved bioavailability compared with enzyme-assisted, microwave-assisted, and conventional methods. The phytochemicals of M. charantia regulate oxidative stress, inflammation, lipid peroxidation, and glucose homeostasis. Studies show that its antidiabetic effects involve improved insulin sensitivity, enhanced glucose uptake, and inhibition of carbohydrate-digesting enzymes. These compounds also exhibit antioxidant activity through free radical scavenging and anti-inflammatory effects via inhibition of the NF-κB and MAPK pathways. M. charantia further demonstrates anticancer activity by inducing apoptosis, causing cell-cycle arrest, and downregulating proliferation pathways in several cancer cell lines, including MCF-7, HCT-116, HepG2, A549, and PANC-1. Beyond medicinal uses, it is applied in the food industry as a functional ingredient in products such as yogurt, cookies, pickles, bread, juice, oil, and beverages. Overall, M. charantia shows strong potential for therapeutic applications, including functional foods and pharmaceutical formulations targeting diabetes, inflammation, liver diseases, and cancer; however, further studies are needed to confirm its clinical efficacy. Full article

Ilyonectria is a common soil-inhabiting fungal genus that comprises numerous plant phytopathogenic species capable of infecting a wide array of crops, medicinal herbs, and horticultural plants. However, the lack of a reliable and efficient genetic transformation method has severely hindered the elucidation of the pathogenic mechanisms of Ilyonectria pathogens. In this study, we established an efficient protoplast-mediated genetic transformation method for two dominant Panax root rot pathogens, I. robusta and I. vredehoekensis. Key parameters governing high-quality protoplast preparation, including mycelium culture time, enzyme composition, osmotic stabilizer type, digestion speed, and digestion time, were systematically optimized. Subsequently, orthogonal experiments were conducted to optimize the PEG-CaCl₂-mediated transformation conditions and to screen regeneration media for protoplasts. The optimal enzymatic system is composed of 20 mg/mL driselase and 10 mg/mL lysing enzyme, with 0.7 M NaCl as the osmotic stabilizer. Under these conditions, high-viability and high-quality protoplasts were obtained from I. vredehoekensis after 3 h of digestion at 150 rpm, and from I. robusta after 2 h of digestion at 100 rpm, yielding 5.52 × 10⁷ CFU/mL and 5.75 × 10⁷ CFU/mL protoplasts, respectively. Efficient transformation was achieved using a mannitol-prepared STC buffer mediated by 40% PEG4000. PCR and fluorescence microscopy verified positive transformants. Additionally, pathogenicity assays showed no significant differences in virulence between the transformed and wild-type strains, suggesting that the transformation procedure did not alter virulence. To the best of our knowledge, this is the first study to successfully establish genetic transformation methods for I. robusta and I. vredehoekensis, providing an essential technical platform for functional gene analysis, pathogenicity studies, and host–pathogen interaction research. In addition, the optimized transformation strategy may serve as a valuable reference for studies on other Ilyonectria species. Full article

Hydrogen-rich water (HRW) has growth-promoting, antioxidant, anti-inflammatory, and microbiota-modulating properties; however, its effects on juvenile snakeheads (Channa argus) remain underexplored. In this experiment, we investigated the effects of HRW on the antioxidant capacity, immune response, and gut microbiota of juvenile snakeheads. A total of 360 fish (15.32 ± 0.50 g) were randomly assigned to three groups: a control group (aerated water), a low-hydrogen group (H1, 280 ± 50 ppb), and a high-hydrogen group (H2, 550 ± 50 ppb). The results revealed that, compared with the control group, H1 significantly reduced serum levels of total protein, triglycerides, glucose, and urea nitrogen (P < 0.05). In the liver, H1 upregulated tir-2 expression and downregulated tnf-α expression (P < 0.05). Furthermore, serum SOD activity was significantly increased in both H1 and H2 groups compared with the control (P < 0.05), while serum CAT activity was significantly elevated only in the H2 group (P < 0.05). No significant alteration was detected in intestinal morphology (P > 0.05), and similarly, digestive enzyme activity did not change significantly (P > 0.05). Regarding gut microbiota, the H1 group increased the relative abundance of Actinobacteria (P < 0.05); at the genus level, it decreased the abundance of Acinetobacter and Pseudomonas, while increasing the abundance of Agathobacter, Faecalibacterium, and Anaerostipes (P < 0.05). In summary, our findings revealed that optimal HRW supplementation enhances immunomodulatory and antioxidant functions and improves intestinal health, thereby establishing HRW as a promising functional water conditioner for sustainable aquaculture applications. Full article

The intestine, particularly the gut microbiota, and the liver play key roles in digestion, nutrient transformation, and immune regulation in fish. However, limited information is available regarding how different ornamental fish species regulate these systems under identical aquaculture conditions. Therefore, this study systematically compared gut microbiota diversity, structural variation, and predicted ecological functions among eight ornamental fish species reared in the same environment, using 16S rRNA high-throughput sequencing combined with digestive enzyme indices and histological analysis of intestinal and liver tissues. The results showed that goldfish (Carassius auratus) and crucian carp exhibited efficient digestive and absorptive capacities, supported by a thickened muscularis and prominent mucosal layers (p < 0.001). High goblet cell density was observed in red swordtail (Xiphophorus hellerii) and Mickey Mouse platy (Xiphophorus hellerii × X. maculatus) (p < 0.001). Larger hepatocyte perimeter and area were observed in red swordtail (p = 0.022, p = 0.015), whereas platinum mini parrot cichlid and sapphire mini parrot cichlid showed significant hepatocyte vacuolization. Microbial analysis showed that the eight fish species had similar α diversity indices, while the gut microbial profiles of Mickey Mouse platy and golden crucian carp differed the most. At the genus level, beneficial taxa such as Lactococcus, Paracoccus, and Cetobacterium were significantly enriched in red swordtail, sailfin molly, and goldfish, respectively, whereas opportunistic pathogens, including Edwardsiella, Aeromonas, and Acinetobacter, were enriched in Mickey Mouse platy, sapphire mini parrot cichlid, and golden crucian carp, respectively (p < 0.05). Functional prediction based on KEGG pathways indicated that sailfin molly and Mickey Mouse platy exhibited the broadest functional enrichment, primarily involving amino acid metabolism, fatty acid metabolism, and antibiotic biosynthesis. Crucian carp and golden crucian carp showed higher activity in amino acid biosynthesis and glycolysis/gluconeogenesis pathways. The two parrot cichlid species were characterized by enrichment in biofilm formation pathways of pathogenic bacteria and amino sugar and nucleotide sugar metabolism pathways. Goldfish and red swordtail were mainly associated with quorum sensing and ABC transporter pathways. These results provide a theoretical foundation for optimizing aquaculture conditions for ornamental fish and improving fish health and production efficiency. Full article

Type 2 diabetes (T2D), a major global health challenge, represents approximately 96% of all cases of diabetes worldwide. Epidemiological forecasts indicate the prevalence of this disease could rise by almost 45% over the next 25 years. T2D is a chronic metabolic disorder characterised by insulin resistance and progressive impairment of β-cell function. Untreated T2D can lead to serious microvascular and macrovascular complications. Traditional therapies have focused primarily on glycaemic control, whereas modern treatment strategies are increasingly centred on the broader pathophysiology of T2D. Among new therapeutic approaches, triazine derivatives have gained significant attention as versatile scaffolds for the development of antidiabetic drugs. This article provides a comprehensive review of triazines (mainly 1,2,4-triazines and 1,3,5-triazines) as promising compounds for the treatment of T2D and its complications. Three databases (Scopus, PubMed, and Web of Science) were searched for the period of 2000–2025. Over the past 25 years, numerous compounds have been described. They were primarily investigated as inhibitors of digestive enzymes and factors that cause diabetic complications. The individual sections discuss the biological activity of these compounds, focusing on SAR analysis and the studies conducted (in vitro, in silico, and in vivo). During this period, two compounds, fotagliptin and imeglimin, have entered clinical use. The results show that triazines have great potential to become antidiabetic drugs. They can not only regulate blood sugar levels (by acting on digestive enzymes, insulin secretion or glucose transport) but also directly prevent serious complications of diabetes. Full article

Anti-nutritional factors (ANFs) in terrestrial plant feeds constrain efficient herbivore production, an issue intensified by rising feed costs and growing demand for animal products. Unlike previous reviews that focus on single ANFs or feed types, this review provides an integrated, cross-species framework linking ANF chemistry, rumen microbial interactions, and mitigation strategies. It examines major ANF classes—tannins, phytates, saponins, oxalates, protease inhibitors, lectins, glucosinolates, and gossypol—and their distribution and biochemical modes of action. Mechanistic pathways are grouped into digestive effects (reduced palatability and enzyme inhibition), microbial effects (altered rumen microbiota and fermentation), metabolic effects (impaired absorption), and mineral interactions (nutrient complexation and chelation). Species-specific responses are evaluated, emphasizing the partial detoxification capacity of the rumen microbiome and the dose-dependent nature of ANF effects. Mitigation strategies—physical, chemical, microbial, enzymatic, probiotic, and genetic—are critically assessed for efficacy, scalability, and sustainability. Emerging metabolomic and metagenomic evidence shows that certain ANFs confer functional benefits at controlled doses; for example, tannins improve nitrogen retention, saponins reduce methane, and phytic acid scavenges free radicals. This synthesis supports strategic management rather than complete elimination, informing safe and sustainable use of terrestrial feeds under evolving food-security and environmental challenges. Full article

Heat and Cd²⁺ stress are major environmental challenges for marine benthic invertebrates. This study examined their combined effects on growth, physiology, and transcriptomic responses in the peanut worm (Sipunculus nudus). After 30 days, Cd²⁺ reduced survival at 26 °C without significantly affecting growth, whereas at 32 °C, both survival and growth declined with increasing Cd²⁺ concentration, indicating that heat stress exacerbates Cd²⁺ toxicity. Cd accumulation increased with exposure concentration but was not affected by temperature. Heat stress increased immune (AKP) and antioxidant (SOD, CAT) enzyme activities, although significant increases in SOD and CAT were observed only under Cd²⁺ exposure. AKP activity rose at low Cd²⁺ concentrations and fell at high Cd²⁺ concentrations at 26 °C, whereas no significant difference occurred at 32 °C between 0 and 0.25 mg/L Cd²⁺. At the same temperature, SOD and CAT activities were significantly higher under high Cd²⁺ exposure than under low Cd²⁺ exposure. Transcriptome analysis showed that Cd²⁺ exposure activated longevity-related pathways, protein processing, and translation initiation. Heat stress activated Jak-STAT signaling and endoplasmic reticulum protein processing while inhibiting the ribosome pathway. Under combined stress, pathways related to xenobiotic metabolism, nutrient digestion and absorption, and amino acid derivative metabolism were broadly suppressed. These results highlight that heat stress exacerbates Cd²⁺ toxicity, affecting growth, enzyme activity, and transcriptomic responses, and provide insights into the adaptive strategies of marine benthic organisms under the combined pressures of climate change and heavy metal pollution. Full article

Iron deficiency is a major global health concern, primarily attributable to inadequate dietary intake and limited absorption of iron. Foliar fertilization of vegetables like bell pepper (Capsicum annuum) may increase their iron content. When especially rich in ascorbic acid, intestinal iron absorption might be improved even further. However, iron content in foods and/or bioaccessibility after in vitro digestion alone would be unreliable predictors of iron bioavailability. Consequently, it seems to be necessary to reconsider digestion models and bioavailability evaluation. The objective of this study was to establish a mucin-enhanced in vitro digestion model to assess the bioavailability of non-heme iron from food matrices in combination with the widely utilized Caco-2 model of intestinal iron absorption. Compared with Fe(III), incubation with 20 µM and 200 µM Fe(II) sulfate increased ferritin formation (normalized to total protein (TP)) in differentiated Caco-2 cells by 80% and 130%, respectively. Furthermore, no loss of cellular viability was observed across the tested Fe(II) and Fe(III) concentrations (20–2000 µM). Three in vitro digestion models (DIN, DIN-lite, and DIN+G), differing mainly in digestive enzyme content, were evaluated for iron bioaccessibility and bioavailability. Only DIN-lite and DIN+G were compatible with Caco-2 cells. Although DIN-lite yielded 25% higher bioaccessible iron than DIN+G, both models resulted in comparable ferritin formation in Caco-2 cells. The DIN+G/Caco-2 model was applied to bell pepper cultivars (‘Ferrari’, ‘Morbidelli’, and ‘Jack Miller’), treated with foliar Fe(II) sprays during cultivation, achieving up to 3.9-fold increased iron content. However, this increase did not translate into enhanced in vitro iron bioavailability in the bell pepper pericarp. Consistent with previous studies, these findings indicate that iron content and bioaccessibility alone are insufficient predictors of iron bioavailability in plant-based foods. At the same time, the mucin-enhanced DIN+G/Caco-2 model proved to be a suitable approach for investigating iron bioavailability in plants. Full article

This study evaluated the responses of growing pigs to a matched compound enzyme in two feeding systems: a corn–soybean meal diet and a diversified diet. Two independent experiments were conducted, each using 80 pigs (Duroc × [Landrace × Yorkshire]; average body weight, 33.0 kg), which were assigned to two treatments in a randomized complete block design (RCBD) according to initial body weight and sex, with five replicate pens per treatment and eight pigs per pen. In Exp. 1, pigs were fed a corn–soybean meal diet without or with 0.02% compound enzyme formulated (including xylanase, β-glucanase, β-mannanase, cellulase and pectinase) for this diet type. In Exp. 2, pigs were fed a diversified diet without or with 0.02% compound enzyme (including xylanase, β-glucanase, β-mannanase, cellulase, pectinase, amylase and protease). The supplemental level of the compound enzyme was selected according to the substrate characteristics of each diet, especially the content of fibrous components, and was further aligned with the inclusion rate recommended for practical feed production. Growth performance, apparent total tract digestibility (ATTD), serum immune and inflammatory indices, jejunal digestive enzyme activities, and cecal microbiota were evaluated. In Exp. 2, the G:F was higher during days 15–28 (p < 0.05) and tended to increase the overall G:F (p = 0.06). In Exp. 1, dietary compound enzyme supplementation increased the ATTD of dry matter (DM), ether extract (EE), and gross energy (GE) on day 28 (p < 0.05), elevated serum immunoglobulin A (IgA) concentration (p < 0.05) on day 14, reduced serum concentrations of interleukin (IL)-1β, IL-6, and IL-8 on day 28 (p < 0.05), and increased jejunal amylase activity (p < 0.05). In Exp. 2, dietary compound enzyme supplementation increased the ATTD of DM, organic matter (OM), crude protein (CP), and GE (p < 0.05), and enhanced the activities of amylase and chymotrypsin on day 28 (p < 0.05). Enzyme supplementation reduced the abundance of Erysipelotrichaceae in Exp. 1 (p < 0.05) but increased the abundance of Chlamydiaceae in Exp. 2 (p < 0.05). In conclusion, matched compound enzyme supplementation improved nutrient utilization in both diet systems, but the response profiles differed. The diversified diet system showed clearer improvements in feed efficiency and protein-related digestibility. Full article