Search Results (6,251)

Osteoarthritis (OA) is increasingly recognized as a mechanically driven whole-joint disease in which abnormal mechanotransduction initiates a cascade of mitochondrial dysfunction, chronic inflammation, and progressive cartilage degeneration. Among the mechanosensitive molecules identified to date, Piezo1 has emerged as a key mechanosensitive regulator linking pathological mechanical loading to intracellular calcium signaling and downstream cellular responses. Growing evidence indicates that persistent Piezo1 activation promotes mitochondrial calcium overload, excessive reactive oxygen species production, ATP depletion, mitochondrial membrane depolarization, and impaired mitophagy, ultimately amplifying chondrocyte dysfunction and extracellular matrix degradation. In parallel, mitochondrial damage triggers immunometabolic reprogramming through activation of the cGAS–STING pathway and the NLRP3 inflammasome. It also promotes pro-inflammatory cytokines, including interleukin-1β, tumor necrosis factor-α, and interleukin-6. Together, these responses may contribute to a self-perpetuating cycle of inflammation and tissue destruction. This review provides a comprehensive synthesis of recent advances regarding the role of Piezo1 in OA, focusing on the mechanistic links between mechanotransduction, mitochondrial dysfunction, mitophagy, and immunometabolic dysregulation. We further discuss the contribution of mitochondrial quality-control pathways, including PINK1/Parkin-, BNIP3-, and FUNDC1-mediated mitophagy, as well as alterations in mitochondrial dynamics involving DRP1, MFN1, MFN2, and OPA1. Emerging experimental models are discussed as valuable tools for accelerating therapeutic discovery. Finally, we critically evaluate current therapeutic strategies targeting the Piezo1–mitochondria axis, including mechanosensitive channel modulation, mitochondrial protection, mitophagy enhancement, gene therapy, biomaterial-assisted delivery, and nanomedicine. Collectively, current evidence supports the Piezo1–mitochondria–immune axis as an important mechanistic framework contributing to OA pathogenesis and as a potential therapeutic target. Integrating mechanobiology, mitochondrial medicine, and precision-engineered experimental models may facilitate the development of next-generation disease-modifying therapies capable of slowing or preventing osteoarthritis progression. Full article

Ozone (O₃) is a prevalent environmental pollutant that can induce oxidative stress and respiratory epithelial injury. Dysregulation of pulmonary microbiota homeostasis plays an important role in the progression of lung damage and inflammatory responses. However, there remains a lack of systematic research on the effects of O₃ exposure on pulmonary microecology and its potential association with pulmonary inflammation. In this study, twenty-three SPF-grade C57BL/6N male mice (aged 6–7 weeks) were randomly divided into a filtered air control group (n = 11) and an O₃ exposure group (n = 12). Mice in the O₃ group underwent whole-body inhalation exposure to 1 ppm O₃ for 4 h daily over 8 consecutive weeks, while control mice were maintained under identical conditions with filtered air exposure. The 1 ppm concentration (equivalent to 0.2–0.3 ppm in humans) and 8-week daily 4 h exposure regimen was selected to model the 2-month summer high-O₃ season with typical afternoon O₃ peaks. The results showed that the O₃-exposed group exhibited marked inflammatory infiltrates in the lung, as well as significantly elevated macrophage inflammatory protein-2 (MIP-2) and tumor necrosis factor-alpha (TNF-α) in bronchoalveolar lavage fluids compared with controls. Pulmonary microbiota sequencing revealed that O₃ exposure significantly elevated the Shannon index of pulmonary microbiota in mice, and four differential genera including Deinococcus, Aerococcus, Enterococcus and Proteiniphilum were identified. Correlation analysis revealed that MIP-2 was significantly correlated with Aerococcus. In conclusion, the findings of this study suggest that exposure to O₃ induces inflammation and significant changes in the microbial composition of the lungs, which provides an experimental basis for further investigating mechanisms linking microbiota dysbiosis to lung injury triggered by ambient air pollutants. Full article

This study investigated the pathological processes by which two Salmonella strains induce orchitis and impair spermatogenesis in mice, with emphasis on inflammation and blood–testis barrier (BTB) integrity. Thirty male Kunming mice were randomly assigned to the human-derived Salmonella enterica serovar Enteritidis H71 group, the sheep-derived Salmonella enterica serovar Agona W42 group, or the phosphate-buffered saline control group (n = 10 per group). An acute orchitis model was established by intrascrotal injection. Histopathological examination revealed marked testicular and epididymal lesions, disruption of the spermatogenic epithelium, and reduced sperm abundance in infected mice. Transcriptomic analysis identified 4546 differentially expressed genes shared by the two infected groups and showed enrichment of the Toll-like receptor (TLR), nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) signaling pathways. Real-time quantitative PCR further showed increased expression of interleukin 6 (Il6), interleukin 1 beta (Il1b), and tumor necrosis factor (Tnf), accompanied by reduced expression of tight junction protein 1 (Tjp1), occludin (Ocln), and synaptonemal complex protein 3 (Sycp3) in infected mice (p < 0.05), except for Tjp1 in the W42 group. These findings indicate that Salmonella-induced inflammatory activation is associated with BTB disruption and impaired spermatogenesis, providing a basis for further investigation of bacterial orchitis and zoonotic reproductive risks. Full article

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine–metabolic disorder frequently associated with insulin resistance (IR) and increased cardiovascular risk. Soluble CD40 ligand (sCD40L) and soluble E-selectin (sE-selectin) are circulating biomarkers reflecting immune activation and endothelial dysfunction, respectively. However, their differential associations with IR in PCOS, particularly in the context of central obesity, remain incompletely understood. This cross-sectional study included 80 women with PCOS stratified according to waist-to-height ratio (WHtR > 0.50 vs. ≤0.50). Clinical, metabolic, hormonal, inflammatory, and endothelial parameters were evaluated. Correlation and multivariable regression analyses were performed to identify independent determinants of circulating sCD40L and sE-selectin. Women with central obesity exhibited significantly higher fasting insulin, homeostatic model assessment for insulin resistance (HOMA-IR), triglycerides, non-high-density lipoprotein (non-HDL) cholesterol, systolic blood pressure (SBP), and sE-selectin concentrations, together with lower HDL cholesterol. No significant differences were observed in tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), or sCD40L. In adjusted regression models, fasting glucose independently predicted sCD40L (β = −0.27, 95% confidence interval (CI): −0.50 to −0.04, p = 0.020), whereas fasting insulin emerged as the strongest determinant of sE-selectin (β = 0.41, 95% CI: 0.17 to 0.65, p < 0.001). These findings suggest distinct associations of immune and endothelial biomarkers with IR in PCOS. Assessment of sCD40L and sE-selectin may provide complementary information for early cardiometabolic risk stratification in affected women. Full article

Joint inflammation and extracellular matrix degradation are major contributors to the development of equine osteoarthritis and reduced athletic performance. Alpha-2-macroglobulin is a naturally occurring broad-spectrum inhibitor of proteases and inflammatory mediators that has emerged as a promising orthobiologic therapy. This study investigated the anti-inflammatory and matrix-protective effects of alpha-2-macroglobulin-enriched plasma in complementary in vitro and ex vivo equine models. Primary equine chondrocytes and synoviocytes isolated from healthy horses were stimulated with interleukin-1β or lipopolysaccharide and treated with alpha-2-macroglobulin-enriched plasma or matched platelet-poor plasma. In parallel, an equine tendon explant model challenged with collagenase was used to evaluate extracellular matrix preservation. Alpha-2-macroglobulin-enriched plasma significantly reduced the production of tumor necrosis factor-α, interleukin-6, and matrix metalloproteinase-13, downregulated interleukin-1β gene expression, and partially restored collagen type II expression in inflamed joint cells compared with platelet-poor plasma. In tendon explants, treatment preserved tissue architecture, reduced collagen degradation, and improved histological indices of matrix integrity under proteolytic challenge. These findings demonstrate that alpha-2-macroglobulin-enriched plasma exerts anti-inflammatory, anti-catabolic, and matrix-protective effects in experimental equine tissues. The results provide mechanistic support for the development of alpha-2-macroglobulin-based orthobiologic therapies as a complementary strategy for the management of synovitis and early osteoarthritis in horses. Full article

Background: Acute respiratory distress syndrome (ARDS) occurs in 20–40% of patients following esophagectomy and is associated with substantial postoperative morbidity and mortality. A major contributor to postoperative ARDS is pulmonary ischemia–reperfusion injury (IRI); however, the role of IRI in ARDS following esophagectomy is not adequately addressed in current experimental models. In this study, we established a large animal model of pulmonary IRI that reproduces key physiological, inflammatory, and histopathological features of pulmonary ischemia–reperfusion-induced acute lung injury relevant to postoperative ARDS after esophagectomy. Methods: Sequential pulmonary ischemia–reperfusion injury was induced in ten anesthetized Landrace pigs using unilateral hilar inflow occlusion. Right lung ischemia was achieved by clamping the hilar inflow for three hours, followed by reperfusion. Subsequently, the left lung underwent two hours of ischemia. Hemodynamic, respiratory, and inflammatory parameters were continuously monitored throughout the experiment. Blood samples were collected to assess leukocyte counts and circulating inflammatory cytokines, including tumor necrosis factor-α and interleukin-6. Lung tissue samples were obtained for histopathological evaluation. Results: ARDS-like lung injury was successfully induced in all animals, with PaO₂/FiO₂ ratios falling below 200 mmHg during the predefined reperfusion observation period. Lung compliance decreased by approximately 50% after ischemia and further declined following reperfusion. Progressive leukocyte elevation and elevated tumor necrosis factor-α and interleukin-6 levels were observed, indicating a systemic inflammatory response. Hallmark features of ARDS were histologically confirmed, including intra-alveolar hemorrhage, interstitial and perivascular edema, and neutrophil infiltration. Conclusions: This porcine model reproduces key physiological, inflammatory, and histopathological features consistent with pulmonary ischemia–reperfusion-induced ARDS-like lung injury. Although it does not reproduce the complete clinical syndrome of post-esophagectomy ARDS, it provides a clinically relevant translational platform for investigating pulmonary ischemia–reperfusion injury and evaluating potential preventive and therapeutic strategies. Full article

Gaseous air pollution is a major environmental risk factor for atherosclerosis, yet the specific molecular networks linking Gaseous air pollution to atherosclerosis are not fully characterized. This study aimed to elucidate how gaseous pollutants drive atherosclerosis using a multi-level framework integrating network toxicology, nine machine-learning algorithms, bulk and single-cell/spatial transcriptomics, molecular docking, clinical tissue/serum validation, and in vitro pollutant-exposure assays. A conserved RXRA–MMP9–TNF axis was identified as a core molecular network linking pollutant exposure to atherosclerosis. Single-cell and spatial transcriptomics showed broad expression of RXRA (Retinoid X Receptor Alpha) in vascular stromal and endothelial cells and its association with xenobiotic and lipid metabolism, whereas MMP9 (Matrix Metallopeptidase 9) and TNF (Tumor Necrosis Factor) were enriched in macrophages, T cells, and mast cells within plaques, correlating with immune cell infiltration. Multiple pollutants displayed high binding affinity to these proteins. Clinical samples showed upregulation of these targets in atherosclerotic tissue and serum. Toluene exposure in THP-1-derived macrophages significantly increased RXRA, MMP9, and TNF mRNA and protein levels. These findings highlight an immune–metabolic interplay centered on the RXRA–MMP9–TNF axis in Gaseous air pollution-driven atherosclerosis, supporting these molecules as candidate biomarkers for environmental health strategies. Full article

Background: Post-cardiac arrest syndrome (PCAS) involves a complex interplay between systemic inflammatory and compensatory anti-inflammatory responses. The hyperacute kinetics of these cytokines and their incremental prognostic value beyond established brain injury biomarkers remain inadequately characterized. We aimed to evaluate whether the 6 h post–return-of-spontaneous-circulation (ROSC) cytokine profile predicts neurological outcome, with the Th1/Th2 ratio largely reflecting the IL-10 signal. Methods: This retrospective analysis of prospectively collected data from a single-center cardiac arrest registry included 56 cardiac arrest survivors (40 out-of-hospital, 16 in-hospital) treated with targeted temperature management (TTM) at 33 °C or 36 °C between January 2024 and December 2025. Serum IL-6, IL-10, IFN-γ (interferon-γ), and TNF-α (tumor necrosis factor-α) were measured at five time points (initial presentation (INIT), and 6, 24, 48, and 72 h post-ROSC). Neurological outcome was assessed using the Cerebral Performance Category (CPC) scale at 6 months after cardiac arrest, with poor outcome defined as CPC 3–5. Results: Eighteen patients (32.1%) had a good outcome (CPC 1–2) and 38 (67.9%) had a poor outcome at 6 months after cardiac arrest. Among the 38 poor-outcome patients, 2 were classified as CPC 3, 8 as CPC 4, and 28 as CPC 5 (death) at 6 months; the 6-month outcome was available for all 56 patients, with no loss to follow-up. Patients with poor outcomes exhibited a synchronized surge of IL-6 and IL-10 peaking at 6 h post-ROSC. IL-10 at 6 h showed the highest discriminative power among cytokines (area under the curve (AUC) 0.844) compared with IL-6 (AUC 0.761). Multivariable analysis using Youden-derived cut-offs revealed that IL-10 ≥ 154.32 pg/mL (adjusted odds ratio (aOR) 15.28, 95% CI 2.02–115.38, p = 0.008) and a Th1/Th2 ratio ≥ 0.0314 (aOR 0.09, 95% CI 0.01–0.61, p = 0.013) were independently associated with neurological outcome after adjustment for age and initial shockable rhythm. Conclusions: The 6 h post-ROSC window is a critical inflection point for immune dysregulation in PCAS. Early IL-10 elevation and collapse of the Th1/Th2 balance are independently associated with poor neurological recovery and add incremental prognostic information to established brain injury biomarkers. External validation in larger prospective cohorts is required. Full article

Background: This study aimed to investigate the effects of E. stephanianum-derived polyphenols on preventing the progression of collagen-induced arthritis (CIA) in mice and its associated metabolic alterations. Methods: The E. stephanianum plant was extracted, fractionated, and screened in vitro for anti-inflammatory, antibacterial, and antioxidant potential. Fraction 5 (identified as ellagic acid by nuclear magnetic resonance) exhibited the most potent activity and was selected for in vivo study. In the in vivo study, male DBA/1JGpt mice were randomized into five groups: control (CON), CIA (Model), low-dose extract (ES-L), high-dose extract (ES-H), and ellagic acid group. ES-L, ES-H, and ellagic acid were administered by daily oral gavage at 375, 750, and 250 mg/kg body weight, respectively, for 8 weeks. Arthritis severity was evaluated based on paw thickness, clinical score, ankle joint histopathology, and serum proinflammatory cytokine levels. To reveal the associated metabolic alterations, serum metabolites were characterized by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Results: Both the whole extract and ellagic acid revealed pronounced anti-inflammatory, antibacterial, and antioxidant properties. In vivo treatment with ES-L, ES-H, or ellagic acid similarly and significantly ameliorated CIA severity, showing smaller paw swelling, reduced clinical arthritis scores, milder joint histopathological injury, and lower serum tumor necrosis factor-α and interleukin-6 concentrations than the model group. Untargeted metabolomics identified 20 differential metabolites, mainly including triacylglycerols (containing n-3 fatty acids), pro-inflammatory phospholipids, and spermic acid 1. Moreover, the treatments significantly altered amino acid and purine metabolism. Conclusions:E. stephanianum derived polyphenols, like ellagic acid, significantly prevented the progress of CIA in mice. These effects were associated with the alteration of metabolic profiles. Full article

Bacterial infection triggered excessive inflammatory responses, yet the mechanisms linking inflammatory activation to immunometabolic adaptation remained incompletely understood. The mitochondrial translocator protein (TSPO) has been implicated in inflammatory activation and cellular metabolism. This study aimed to investigate the role of TSPO in inflammation mediated by Toll-like receptor 4 (TLR4). Herein, we integrated transcriptomic data from the human peripheral blood dataset GSE72829, and single-cell transcriptomic profiles from the CELLxGENE platform with cellular mechanistic experiments in BV2 microglia and RAW264.7 macrophages. Transcriptomic analyses revealed that TSPO expression was markedly upregulated in patients with bacterial infection (n = 52) and exhibited diagnostic potential to distinguish bacterial infection from healthy controls (HCs, n = 16) and viral infection (n = 92). TSPO-correlated genes were enriched in Toll-like receptor (TLR) signaling, inflammatory response, and immunometabolic pathways. Mechanistically, TSPO interacted with TLR4 and selectively modulated TLR4-driven inflammatory activation. TSPO deficiency augmented lipopolysaccharide (LPS) induced tumor necrosis factor‑α (TNF-α) and interleukin‑6 (IL-6) secretion, accompanied by disrupted Ca²⁺ homeostasis, impaired cholesterol balance, and compensatory metabolic remodeling characterized by elevated L-lactate and sustained Adenosine triphosphate (ATP) levels. Collectively, these findings identified TSPO as an immunometabolic regulator bridging TLR4 signaling and metabolic adaptation during inflammatory activation. Besides, TSPO represented a promising biomarker and therapeutic target to limit exaggerated inflammatory responses. Full article

Acinetobacter baumannii, particularly colistin-resistant strains, represents a major therapeutic challenge because of multidrug resistance, biofilm formation, and limited treatment options. This study investigated the antibacterial, antibiofilm, immunomodulatory, and therapeutic potential of Withania somnifera ethanolic root extracts (WSEEs) against drug-sensitive (DS) and colistin-resistant (CR) A. baumannii. WSEE exhibited concentration-dependent antibacterial activity, with MIC/MBC values of 125/250 μg/mL against the DS isolate and 250/500 μg/mL against the CR isolate. Time–kill analysis demonstrated bactericidal activity at 250 μg/mL, and WSEE significantly reduced the biomass of preformed biofilms. In cyclophosphamide-induced leukopenic mice, oral administration of WSEE (100 and 200 mg/kg) restored leukocyte counts and significantly reduced pulmonary bacterial burden following infection with both isolates. The higher dose (200 mg/kg) achieved survival rates of 90% and 70% in mice infected with the DS and CR isolates, respectively, compared with 50% and 30% in the corresponding colistin-treated groups. WSEE also significantly decreased serum levels of the pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), indicating attenuation of infection-associated inflammation. Biochemical analyses further showed that WSEE did not produce detectable hepatotoxicity or nephrotoxicity under the experimental conditions. Collectively, these findings demonstrate that WSEE possesses antibacterial, antibiofilm, anti-inflammatory, and immunomodulatory activities and provides therapeutic benefit in experimental A. baumannii infection. These results support the potential of WSEE as a complementary therapeutic strategy against multidrug-resistant A. baumannii, while further mechanistic, pharmacokinetic, and translational studies are needed to validate its clinical potential. Full article

Cancer-associated cachexia (CAC) is a multifactorial syndrome characterized by systemic inflammation, muscle wasting, and progressive functional decline, affecting up to 80% of patients with advanced cancer. The inconsistent diagnostic criteria limit comparability across studies and hinder translation into clinical practice. Inflammatory biomarkers, including interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), and serum albumin, have been studied as markers of the presence, severity, and progression of CAC. This review synthesizes evidence linking these five biomarkers to key manifestations of CAC, including weight- loss, muscle depletion, fatigue, quality of life, and survival. A structured search of PubMed, Embase, and Web of Science studies published between 2000 and 2025, yielding 20 articles for final synthesis to evaluate biomarker patterns and their potential utility for early detection and risk stratification. IL-6 and CRP show consistent associations with muscle wasting and systemic inflammatory burden. Albumin and NLR demonstrate enhanced prognostic value when incorporated into composite indices such as the Cachexia index. TNF-α remains mechanistically relevant but shows limited predictive utility when assessed independently. CRP, Albumin, and NLR are derived from routine, low-cost tests, whereas IL-6 and TNF-α require specialized cytokine assays. Future research is warranted to standardize diagnostic criteria and validate biomarker thresholds to develop an accessible, multi-biomarker panel for improved detection and monitoring of CAC. Full article

Spinal cord injury is strongly associated with male infertility, traditionally attributed to erectile and ejaculatory dysfunction. However, accumulating evidence demonstrates that infertility in this population extends beyond neurogenic impairment and involves profound biochemical and molecular alterations within the male reproductive system. The objective of this review is to synthesize current evidence on the role of oxidative stress, inflammation, and sperm DNA damage as central mechanisms driving impaired fertility in men with spinal cord injury. A comprehensive evaluation of clinical and experimental studies indicates that seminal plasma in affected individuals is characterized by elevated reactive oxygen species, reduced antioxidant capacity, and a pro-inflammatory cytokine profile, including increased levels of tumor necrosis factor alpha, interleukin 6, and interleukin 1 beta. These alterations are closely linked to leukocytospermia, mitochondrial dysfunction, and disruption of the blood–testis barrier, creating a toxic microenvironment that compromises sperm function. As a consequence, spermatozoa exhibit reduced motility, impaired membrane integrity, and significantly increased DNA fragmentation and chromatin abnormalities. Elevated sperm DNA damage has been consistently associated with poor fertilization outcomes, reduced embryo quality, and increased risk of pregnancy loss in assisted reproductive settings. Importantly, these molecular defects persist even when sperm are retrieved using advanced techniques such as electroejaculation or surgical extraction, highlighting the need for targeted therapeutic strategies. Interventions aimed at reducing oxidative stress and modulating inflammation, including antioxidant supplementation and advanced sperm selection methods, show promise but remain insufficiently standardized. Future research should focus on the development of personalized approaches integrating molecular diagnostics and targeted therapies to improve reproductive outcomes in this population. Collectively, this review reframes spinal cord injury-related infertility as a complex inflammatory and oxidative disorder and underscores the importance of addressing sperm DNA integrity in clinical management. Full article

This study evaluated the effects of replacing whole-plant corn silage with cotton stalk and sugar beet pulp mixed silage at 0, 30, 60, or 90% on growth performance, serum parameters, and rumen characteristics in Suffolk ram lambs, addressing the lack of systematic research on moderate-to-high replacement ratios in sheep diets. Eighty-four 4-month-old ram lambs (32.36 ± 2.92 kg) were assigned to four treatments (3 pens/treatment, 7 lambs/pen) for a 120-day trial after a 15-day adaptation. Based on the growth performance and serum parameter results, the control and 60% replacement groups were selected for further analysis of rumen fermentation and bacterial microbiota via 16S rRNA gene sequencing. Compared with the control, the 60% replacement group showed increased final body weight (+15.7%, p < 0.01), daily weight gain (+38.4%, p < 0.01), and dry matter intake (+8.6%, p < 0.05), and improved feed-to-gain ratio (F:G) (p < 0.01). Serum immunoglobulin A and G increased (p < 0.05), whereas tumor necrosis factor-α and interleukin-1β decreased (p < 0.05) in the 60% and 90% replacement groups. Serum MDA was significantly lower in the 90% CSBPS group than in the control at d 90 (p < 0.05), with no significant differences among groups at d 120. Rumen isobutyric and valeric acid concentrations were greater in the 60% replacement group than in the control (p < 0.05), accompanied by enrichment of fiber-degrading bacteria including the Lachnospiraceae NK3A20 group. Replacing 60% of whole-plant corn silage with cotton stalk and sugar beet pulp silage was associated with improved growth performance, enhanced immune function and antioxidant status, and optimized rumen fermentation in Suffolk ram lambs under the conditions of this study. Full article

This study evaluated the effects of dietary supplementation with a commercial lactoferrin–osteopontin complexes preparation (LF-OPN; LF:OPN mass ratio 8:1; 240 mg/kg body weight) on growth, immune indices, antioxidant status, intestinal barrier-related markers, fecal microbiota, short-chain fatty acids (SCFAs), peripheral lymphocyte subsets, and the whole-blood transcriptome of growing British Shorthair kittens. Sixteen kittens were randomly assigned to either a basal diet group (CON) or a group supplemented with LF-OPN complexes (LFT) for 28 days. LF-OPN supplementation did not significantly affect body weight or average daily gain. On D28, the LFT group had a higher serum immunoglobulin M concentration and a lower tumor necrosis factor-α concentration (p < 0.05). Serum superoxide dismutase and glutathione peroxidase activities and total antioxidant capacity were higher, whereas malondialdehyde was lower (p < 0.05) in the LFT group (p < 0.01). Fecal 16S rRNA gene sequencing revealed no significant difference in alpha diversity; howerer, LEfSe identified selective taxonomic difference, including higher relative abundances of Holdemanella and Erysipelotrichaceae and lower relative abundances of Enterobacteriaceae and Escherichia-Shigella in the LFT group. Fecal short-chain fatty acid concentrations were unchanged. Flow cytometry revealed a higher proportions of peripheral CD4+ lymphocytes and a higher CD4+/CD8+ ratio in the LFT group (p < 0.01), whereas the CD8+ proportion was unchanged. Whole-blood RNA sequencing identified 283 differentially expressed genes (199 upregulated and 84 downregulated), with enrichment of immune-related pathways including hematopoietic cell lineage, antigen processing and presentation, cytokine–cytokine receptor interaction, NF-κB signaling, and IL-17 signaling, but these findings were not independently validated. The tested LF-OPN preparation was well tolerated and was associated with elevated antioxidant status, altered immune indices, and selective modulation of the fecal microbiota in growing kittens. The study does not establish synergy or identify the individual contributions of either protein. Full article